Our webpages must be accessible so we have our documents in printable/downloadable PDF version first, then we have the document in a webpage version. You may need to scroll through the page to find the document you are looking for.

Documents on this page:

  1. 4-H Permission to Travel Form
  2. 4-H Chaperone Medical Release Form
  3. 4-H Chaperone Media Release Form
  4. Shooting Sports Release Form
  5. Market Livestock Project: Small Livestock Scale Use Contract Check Out Form
  6. Market Livestock Project: Sheep Sheer Use Contract & Check Out Form
  7. 4-H Name and Emblem Use Handbook: Find and download at https://www.montana.edu/extension/4h/resources/4-H_brand.html 
  8. Pasture Management: Pasture Management Tips
  9. Pasture Management: Overgrazing Article
  10. Spiders, Insects and Plant Disease: Grasshopper Insecticide Module
  11. Spiders, Insects and Plant Disease: Grasshopper Management Module
  12. Spiders, Insects and Plant Disease: Grasshopper Scouting Module
  13. Spiders, Insects and Plant Disease: Bark Beetle
  14. Spiders, Insects and Plant Disease: Douglas Fir Tussock Moth
  15. Spiders, Insects and Plant Disease: How to Identify a Hobo Spider
  16. Spiders, Insects and Plant Disease: Managing Mountain Pine Beetle
  17. Spiders, Insects and Plant Disease: Montana Bee Identification Guide
  18. Spiders, Insects and Plant Disease: MSU IPM Biological Controls
  19. Spiders, Insects and Plant Disease: Needle Cast Diseases of Conifers
  20. Spiders, Insects and Plant Disease: Powdery Mildew (Colorado State Extension)
  21. Spiders, Insects and Plant Disease: Raspberry Cane Borer New Hampshire
  22. Spiders, Insects and Plant Disease: the use of BT for Spruce Bud Worm
  23. Spiders, Insects and Plant Disease: Western Spruce Bud Worms
  24. Weeds: Blueweed download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Blueweed-EB0195__EB0195.aspx 
  25. Weeds: Curly Leaf Pond Weed download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Curlyleaf-Pondweed-EB0223__EB0223.aspx 
  26. Weeds: Eurasian Watermilfoil download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Eurasian-Watermilfoil-EB0193__EB0193.aspx 
  27. Weeds: Flowering Rush download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Flowering-Rush-EB0201__EB0201.aspx 
  28. Weeds: Hoary Alyssum download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Hoary-Alyssum-EB0194__EB0194.aspx 
  29. Weeds: Montana Knapweed download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Montana-Knapweeds-EB0204__EB0204.aspx 
  30. Weeds: Scotch Broom download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Scotch-Broom-EB0202__EB0202.aspx 
  31. Weeds: The Knotweed Complex download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-the-Knotweed-Complex-EB0196__EB0196.aspx 
  32. Weeds: Western Salsify download at https://store.msuextension.org/Products/Western-Salsify-MT201113AG__MT201113AG.aspx 
  33. Weeds: White Bryony 
  34. Weeds: Whitetop download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Whitetop-EB0138__EB0138.aspx 
  35. Weeds: Yellow Starthistle download at https://store.msuextension.org/Products/High-Priority-Invasive-Species-Yellow-Starthistle-MT201808AG__MT201808AG.aspx 
  36. Weeds: Yellowflag Iris download at https://store.msuextension.org/Products/Biology-Ecology-and-Management-of-Yellowflag-Iris-EB0203__EB0203.aspx 
  37. Weeds: Oxeye Daisy download at https://store.msuextension.org/Products/Oxeye-Daisy-Identification-Biology-and-Integrated-Management-MT200002AG__MT200002AG.aspx 
  38. Yard and Garden: Composting Article
  39. Yard and Garden: Frost free Days Chart-MSU Creston research Station
  40. Yard and Garden: Ground Squirrels
  41. Yard and Garden: Home garden Soil Testing MontGuide download at https://store.msuextension.org/Products/Home-Garden-Soil-Testing-and-Fertilizer-Guidelines-MT200705AG__MT200705AG.aspx 
  42. Yard and Garden: Proper Watering 
  43. Yard and Garden: Spray Schedule for Apple Trees-WSU
  44. Yard and Garden: Spray Schedule for Cherry Trees-WSU
  45. Yard and Garden: Spray Schedule for Peach and Apricot Trees-WSU
  46. Yard and Garden: Spray Schedule for Pear Trees-WSU
  47. Yard and Garden: Spray Schedule for Plum and Prune Trees-WSU

4-H Documents

Permission to Travel Form

Printable version of Permission to Travel Form (PDF)


Date: ____________

County:  Flathead                            

Name of Participant: _____________________________________

MSU Extension 4H programs schedule a number of activities and events which involve travel by way of motor vehicle. When part of the activity or event, the authorized organizers of these activities and events may coordinate, arrange, and/or provide transportation for 4H participants.

All participants are expected to utilize this transportation, as it is provided, unless written permission from the 4H participant's parent(s) or legal guardian is obtained by use of this form.

MSU Extension 4H recognizes that there are circumstances wherein the 4H participant may be required or chooses to provide his/her own transportation in conjunction with scheduled 4H activities or events. MSU Extension 4H may allow 4H participants to opt out of the transportation provided by the authorized 4H event organizers. In order to opt out of the travel requirements set forth by the authorized 4H activity or event organizers, the participant and parent/legal guardian must authorize and request this alternative to 4H provided transportation by completion of the following:

As a Participant:

I hereby request to be allowed to provide for my own travel to any or all events or activities scheduled by a 4-H club or MSU Extension 4-H. This includes operating my own vehicle, a vehicle provided by       another, or traveling with an individual of my choice. By doing so, I understand the risks associated with this travel option and hereby agree to hold harmless, Montana State University, MSU Extension 4H, the State of Montana, 4H leaders, volunteers, officials, sponsors, supervisors or other MSU Extension 4H authorized individuals for any personal injury or claim resulting from my travel to or from any 4H activity or event.

Participant's Signature___________________________________________ Date_____________ 

As Parent or Legal Guardian:  

I hereby request and authorize my minor child to travel to any or all MSU Extension 4H activities or events organized, scheduled, or arranged by a 4-H club or MSU Extension 4-H by traveling with the person of my child's choice or by operating his/her own motor vehicle or a motor vehicle provided by another. In requesting and authorizing travel not arranged or provided by the authorized 4H activity or event organizers or officials, I clearly understand the risks associated with my child's travel and assume all risks thereof. I hereby agree to hold harmless, defend and indemnify Montana State University, MSU Extension 4H, the State of Montana, 4H leaders, volunteers, officials, sponsors, supervisors or other MSU Extension 4H authorized individuals for any personal injury or claim resulting from my child's travel to or from any 4H activity or event. 

Parent/Legal Guardian Signature __________________________________ Date_____________

Both participant and parent/legal guardian must sign

The Montana State University Extension Service is an ADA/EO/AA/Veteran’s Preference Employer and Provider of Educational Outreach. 

Chaperone Medical Release Form

Printable version of the Chaperone Medical Release Form Fillable (PDF)


Medical Release Form for 4-H Youth & Adults


Name:______________________________________________ County:____________


Name of Parent or Legal Guardian: (YOUTH ONLY):_____________________________

Primary Physician:_________________________________________________ Phone:

Dentist:__________________________________________________________ Phone:


Primary Contact:__________________________________________ Phone:______________________

Relationship:___________________________ City:_____________________________________ State:

Alternate Contact:__________________________________________ Phone:_____________________

Relationship:___________________________ City:_____________________________________ State:

Name of Insurance Carrier:

Policy Holder Name:_______________________________________ Policy #:

Date of Last:

To the Best of my knowledge, accurate information has been provided in all areas of this form.

Participant Signature (youth/ adult)___________________________________________ Date

IF YOUTH: Parent/Guardian Signature__________________________________________ Date


The Montana State University Extension Service is an ADA/EO/AA/Veteran's Preference Employer and Provider of Educational Outreach.

Chaperone Media Release Form

Printabe version of the Chaperone Media Release Form Fillable (PDF)


Media Release Form

Montana State University Extension



Name of participant





Name of event or activity


Date and Location of event or activity


The MSU Extension Service—4-H may like to use photos or video of your child that was taken during the above event or activity to use in a press release and other publicity related to this event. The photo or film may be used for the following purposes:


  • Website
  • Press Release
  • News Story
  • Marketing materials
  • Other




Do you authorize the use of photos or video of your child at this event or activity?


YES                     NO



I consent and agree, individually and, as a parent or guardian of the minor named above, to the foregoing terms and provisions. By signing below, I hereby waive any right that I (and a minor) may have to inspect or approve the copy and/or finished product or products that may be used in connection therewith or the use to which it may be applied. I warrant that I am of full legal age and have every right to contract for the minor in the above regard. I

have also read and understand the conditions of use listed below.




Parent or Guardian Signature                                                                            Date                         





  1. We will not use personal details or full names (first name and last name) of any child in a photograph on our web site.
  2. We will not include personal e-mail or postal addresses, telephone or fax numbers on our web site or in other printed publications.
  3. We may use the name of the child in accompanying text or a photo caption.
  4. We may use group or photographs with very general labels.
  5. We will only use images of children in suitable dress, to reduce the risk of inappropriate use of images.




The Montana State University Extension Service is an ADA/EO/AA/Veteran's Preference Employer and Provider of Educational Outreach.

Shooting Sports Release Form

Printable version of the Shooting Sports Release Form (PDF)

Flathead County 4-H Shooting Sports

Release, Assumption of Risk & Agreement to Hold Harmless


I am aware that my child’s participation in 4-H Shooting Sports events can be a dangerous activity involving many risks to injury. I fully recognize, appreciate and understand the dangers and risks inherent in 4-H Shooting Sports events, and during transportation to and from the 4-H event site included, but are not limited to, death or serious bodily injury. I understand that the dangers and risks of participating in 4-H events and/or travel may result in not only serious injury, but in a serious impairment of my child’s future abilities to earn a living, to engage in other businesses, social and recreational activities and generally to enjoy life.


In consideration of my child’s being permitted to participate in 4-H Shooting Sports events and/or travel, I hereby assume all the risks associated with participation and necessary travel and agree to hold MSU Extension, Flathead County, their trustees, officers, employees, agents, representatives and volunteers harmless from any and all liability, actions, causes of action, debts, claims, or demands of any nature whatsoever which may arise by or in connection with my child’s participation in 4-H events and/or travel. The terms hereof shall serve as a release and assumption of risk for me, my heirs, estate, executor, administrator, assignees and for all members of my family.


I, the undersigned parent(s) and lawful guardian(s) hereby execute the foregoing Release and to Consent for and on behalf of my minor child and/or ward. I have carefully read the foregoing release and consent and sign on my own free act. I hereby certify that I am lawfully empowered to enter into this release and do consent to bind my child and myself hereby.


Parent/Legal Guardian Printed Name 



Signature                                                   Date 



Child’s Name                                              Date of Birth 


 The Montana State University Extension Service is an ADA/EO/AA/Veteran’s Preference Employer and Provider of Educational Outreach.

Small Livestock Scale Use Contract Check Out Form

Printable version of Small Livestock Scale Use Contract Check Out Form (PDF)

USE CONTRACT FOR Flathead County 4-H Council Small Livestock Scale

Notice – By signing this document you may be waiving certain legal rights, including the right to sue.

Release and Waiver of Claims; Assumption of the Risk; Indemnification Agreement

In consideration of being allowed to use the equipment provided by Flathead 4-H Council, the Participant, and the Participant’s parent(s) or legal guardian(s) if the Participant is a minor, do hereby agree to the fullest extent permitted by law, as follows:

1) TO ASSUME ALL RISKS associated with the handling of animals and the use equipment in weighing small livestock, even those risks caused by faulty equipment or lack of training administered to the user. The Participant and his/her parent(s) or legal guardian(s) understand that there are inherent risks associated with animal handling and shearing equipment, which may be both foreseen and unforeseen and include serious physical injury and death to the lamb and serious injury to the equipment user.

2) TO RELEASE the owner, affiliates, operators, and agents from all liability for any loss, damage, injury, death, or expense that the Participant (or his/her next of kin) may suffer, arising out of his/her use of the Equipment. The Participant and his/her parent(s) or legal guardian(s) specifically understand that they are releasing any and all claims that arise or may arise from any negligent acts or conduct of the owners, affiliates, operators, and agents to the fullest extent permitted by law. However, nothing in this Agreement shall be construed as a release for conduct that is found to constitute gross negligence or intentional conduct; and

3) TO BE HELD LIABLE in the case of any damage caused to the Equipment during travel, use, storage, etc, the Participant and his/her parent(s) or legal guardian(s) understand that they are responsible for monetary compensation for either the replacement or repair of the Equipment. The Participant is also under the understanding that they are responsible to report any problems associated with the Equipment that occurred under their care and that they are thus responsible for any damages found between the point of equipment check out and the inspection upon the return of said equipment.  

Personal Responsibility

The Flathead 4-H Small Livestock Scale may not be moved from its location.

Non-4-H users agree to pay a $35 use fee to the Flathead 4-H Council.

Users agree to thorough cleaning and disinfecting of the equipment by removing all animal waste from the equipment and its immediate surrounding. Users will also agree to use a disinfectant solution on the equipment.  

The Participant and his/her parent(s) or legal guardian(s) certify that Participant has no physical or mental condition that precludes him/her from using the equipment and that he/she is not participating against medical advice.

The Participant and his/her parent(s) or legal guardian(s) understand that Participant’s use of equipment is voluntary and further understand that they have the opportunity to inspect the Equipment before use.

The Participant and his/her parent(s) or legal guardian(s) understand that Participant is obligated to follow the rules and instructions of the Equipment and that he/she can minimize his/her risk of injury and injury to their animal by doing so and through the exercise of common sense and by being aware of his/her surroundings.

The Participant and his/her parent(s) or legal guardian (s) understand that the knowledge of proper use and handling of the equipment is the full responsibility of themselves and the owner is at no obligation to be held liable for harm or damage to either the Equipment or the participant/animal from misuse or lack of knowledgeable handling.    

If, while using the Equipment, the Participant or his/her parent(s) or legal guardian(s) observe any unusual hazard or malfunction, which they believe jeopardizes the user’s personal safety or that of others/animals, the user and/or his/her parent(s) or legal guardian(s) will remove the animal from the equipment and stop the use of all equipment and shall also bring said hazard or malfunction to the attention of the owner.

To the extent that any portion of this Agreement is deemed to be invalid under the law of the applicable jurisdiction, the remaining portions of the Agreement shall remain binding and available for use by the owner in any proceeding. I HAVE READ AND UNDERSTAND THIS AGREEMENT AND I AM AWARE THAT BY SIGNING THIS AGREEMENT I MAY BE WAIVING CERTAIN LEGAL RIGHTS, INCLUDING THE RIGHT TO SUE.

By signing below, I agree to accept liability for the equipment listed below. I understand that should any damages occur while the equipment is in my possession, I will be held fully responsible and liable for the

Signature       ______________________________________    Date ________________

Contact Name ______________________________________________________

Event & Date _______________________________________________________

Contact Number _____________________________________________________

Sheep Sheer Use Contract and Check Out Form

Printable version of Sheep Sheer Use Contract & Check Out Form (PDF)


Notice – By signing this document you may be waiving certain legal rights, including the right to sue.

Release and Waiver of Claims; Assumption of the Risk; Indemnification Agreement

In consideration of being allowed to use the equipment provided by Flathead 4-H Extension and Flathead Sheep Committee, the Participant, and the Participant’s parent(s) or legal guardian(s) if the Participant is a minor, do hereby agree to the fullest extent permitted by law, as follows:

1) TO ASSUME ALL RISKS associated with the handling of animals and the use equipment in shearing lambs, even those risks caused by faulty equipment or lack of training administered to the user. The Participant and his/her parent(s) or legal guardian(s) understand that there are inherent risks associated with animal handling and shearing equipment, which may be both foreseen and unforeseen and include serious physical injury and death to the lamb and serious injury to the equipment user.

2) TO RELEASE the owner, affiliates, operators, and agents from all liability for any loss, damage, injury, death, or expense that the Participant (or his/her next of kin) may suffer, arising out of his/her use of the Equipment. The Participant and his/her parent(s) or legal guardian(s) specifically understand that they are releasing any and all claims that arise or may arise from any negligent acts or conduct of the owners, affiliates, operators, and agents to the fullest extent permitted by law. However, nothing in this Agreement shall be construed as a release for conduct that is found to constitute gross negligence or intentional conduct; and

3) TO BE HELD LIABLE in the case of any damage caused to the Equipment during travel, use, storage, etc, the Participant and his/her parent(s) or legal guardian(s) understand that they are responsible for monetary compensation for either the replacement or repair of the Equipment. The Participant is also under the understanding that they are responsible to report any problems associated with the Equipment that occurred under their care and that they are thus responsible for any damages found between the point of equipment check out and the inspection upon the return of said equipment.  

Personal Responsibility

The Participant and his/her parent(s) or legal guardian(s) certify that Participant has no physical or mental condition that precludes him/her from using the equipment and that he/she is not participating against medical advice.

The Participant and his/her parent(s) or legal guardian(s) understand that Participant’s use of equipment is voluntary and further understand that they have the opportunity to inspect the Equipment before use.

The Participant and his/her parent(s) or legal guardian(s) understand that Participant is obligated to follow the rules and instructions of the Equipment and that he/she can minimize his/her risk of injury and injury to their animal by doing so and through the exercise of common sense and by being aware of his/her surroundings.

The Participant and his/her parent(s) or legal guardian (s) understand that the knowledge of proper use and handling of the equipment is the full responsibility of themselves and the owner is at no obligation to be held liable for harm or damage to either the Equipment or the participant/animal from misuse or lack of knowledgeable handling.    

If, while using the Equipment, the Participant or his/her parent(s) or legal guardian(s) observe any unusual hazard or malfunction, which they believe jeopardizes the user’s personal safety or that of others/animals, the user and/or his/her parent(s) or legal guardian(s) will remove the animal from the equipment and stop the use of all equipment and shall also bring said hazard or malfunction to the attention of the owner.

To the extent that any portion of this Agreement is deemed to be invalid under the law of the applicable jurisdiction, the remaining portions of the Agreement shall remain binding and available for use by the owner in any proceeding. I HAVE READ AND UNDERSTAND THIS AGREEMENT AND I AM AWARE THAT BY SIGNING THIS AGREEMENT I MAY BE WAIVING CERTAIN LEGAL RIGHTS, INCLUDING THE RIGHT TO SUE.

The U.S. Department of Agriculture (USDA), Montana State University and the Montana State University Extension prohibit discrimination in all of their programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital and family status. Issued in furtherance of cooperative extension work in agriculture and home economics, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Jeff Bader, Director of Extension, Montana State University, Bozeman, MT 59717

By signing below, I agree to accept liability for the equipment listed below. I understand that should any damages occur while the equipment is in my possession, I will be held fully responsible and liable for the full amount of the repairs/replacement of the equipment.

Date Out





Date In





























































































































































Agruiculture Documents

Pasture Management Tips

Printable version of Pasture Management Tips (PDF)

Pasture Management Tips

Small parcels of land less than 100 acres continue to be a land management challenge. Often people that move into the valley have never cared for more than a residential lot. They tell me that they have moved to the Flathead to “live the Montana Dream.” Often this means, to them, owning horses and/or cattle. What I’d like to address is that there is a discrepancy between what is allowed by law and what are good land stewardship practices.

Flathead County zoning department states that certain residential areas are approved to have two horses per acre. Real estate agents use this to sell property. “sure you can put 10 horses on this five-acre piece of ground. Why not?” When the five acre ranchette becomes a dry lot filled with weeds, the resident doesn’t always know what happened. Montana State University range specialist, Jeff Mosely, said that with the rainfall in the Flathead, the stocking rate should be one animal unit per 10 acres. An animal unit is a 1,000 lb. cow-calf pair. A horse is considered 1.5 animal units. A horse rarely stops grazing while cows lay down to ruminate several times a day. Stocking rates can be adapted depending on a land owner’s willingness to use alternative methods such as using a dry lot, rotational grazing, irrigation and assorted grass varieties.

Understanding the physiology of grass and the impact of over grazing is critical to good management. Grasses do not store all of their carbohydrates (energy) in their roots like other plants. The grass stores most of its carbohydrates in the lower 2-3” of the blade. Livestock prefer eating this lower portion because it is sweeter to the taste and more palatable. Once this area of the plant is removed, there is no energy to regrow the plant. Additionally, roots grow in proportion to the top growth. Grass that has been eaten to about ¼”, have about ½” roots. Grasses that have been allowed to grow to 8-10” have about 12” roots. It’s easy to visualize how over grazed grass is easily pulled from the ground when the roots are barely holding on. Scalped grass also succumbs to drought quickly. Open areas of soil that occur when grass dies or is pulled out, is fertile ground for weed seeds to blow in and become established. Another trait often unrecognized is that our traditional cool season pasture grasses lose their roots after the solstice of June 21 each year. Farmers often call it the “summer slump”. The grass just doesn’t grow. This is due to their preference for cool weather and that they don’t have an active root system. This is the time that the grass needs to rest and recover and not be under pressure by livestock.

Livestock do not eat most of Montana’s noxious weeds. Some are actually poisonous to livestock. When these weeds find an over grazed pasture it is a perfect setting to flourish since the competition for water and nutrients has been eliminated. Jed Fisher, Flathead County Weeds and Parks, says that a high percentage of their calls come from poorly managed livestock facilities. The weeds contain tannins and other compounds that taste bitter to the animal. When left with no other food source, livestock will eventually eat the noxious weed and can become seriously ill or die.

Pasture grass must be allowed to get to 10” or so in the spring before livestock are put on it. When the ground is soft from winter snow melting and early season rains, it is easily compacted by hooves. The grass can be removed by the roots and the carbohydrate stores eliminated. There is no time for the blades of grass to grow and photosynthesize the carbohydrates necessary for survival. I’ve seen pastures made completely useless in less than 2 years by putting livestock on too early. The fall is an important time to be careful of overgrazing also. As mentioned, if the top growth of the grass is too short, there will not be enough roots to survive the winter and no carbohydrates for spring growth.

There is no time of year that over grazing is acceptable. The use of a dry lot to allow pastures to rest is necessary on most farms of limited acreage. The use of electric fence to keep animals rotating through an area can be helpful.

Dr. Emily Glunk is the MSU forage specialist. She is available via email for questions and is planning to continue collaborating with Flathead Extension Agent Pat McGlynn to provide an annual pasture management workshop in Kalispell.

Overgrazing Article

Printable version of Overgrazing Article (PDF)

Overgrazing a common problem on local small-acreage farms


Daily Inter Lake

Ranchettes are plentiful in the Flathead Valley, but if pastures aren’t managed correctly, weeds can also be plentiful. A group of more than 30 small-acreage

horse and cattle owners gathered near Foy’s Lake last week to learn how to avoid overgrazing their land. The free workshop was offered by the Montana State University Extension Service and will become an annual event. “A problem that is increasing in the Flathead Valley has been the number of people who buy small acreage— five to 20 acres — and put several horses on it, wishing to live the ‘Montana Dream,’” said Pat McGlynn, MSU Extension agent for Flathead County. “These horses quickly eat all of the available plants and this is when the problem begins.” Once the grass has been consumed, noxious weeds move in where the soil has been disturbed. “Landowners may not realize that grasses do not store their carbohydrates, or energy in their roots like other plants,” McGlynn said. The grass stores carbohydrates in the lower two to three inches of the blade. When people allow horses, cattle, goats or sheep to eat the grass below a 3-inch level, all the way to the soil, the grass cannot grow back, McGlynn explained. “It has no energy reserves and the meristem, where the plant begins, has been eliminated,” she said. “Only weeds can grow. The weeds are not palatable to the livestock so they avoid them. This is the perfect storm as far as the noxious weed problem in

our area.” McGlynn said she gets calls about pasture management several times a week. She plans to offer the free workshop each summer during the third

week in July. “It was such a good group,” she said of the workshop participants. “So many people said, ‘I have to tell my neighbor about this.’” According to MSU Range Management Specialist Jeff Mosley, 10 acres for one horse, with a five- to sixmonth grazing season, is the recommended stocking rate for the Flathead Valley. But the matter of how many animals a pasture can sustain depends on the length of the grazing season, whether the property is irrigated or not, and whether the animals alternate between a dry lot and grazing land. Flathead County zoning regulations, however, allow two horses per acre in several zoning districts, including suburban agriculture 5- and 10-acre zones and some residential zones. That ratio puts Flathead pasture land at a greater risk of overgrazing if property owners don’t fully understand pasture management, McGlynn said. As summer days get shorter late in the season, grasses shed their roots and that’s when it’s most important to rest pastures. “People really should have their animals on a dry lot in July to August 1 and then put them back out [to pasture],”

McGlynn said. “But no one wants to feed hay when they can see grass ... as soon as the overgrazed land gets a tiny bit of green, animals will overeat because the new growth is more palatable, so the pasture never gets to rest.” Animal owners also may underestimate how much horses eat in a short amount of time, McGlynn said. “They eat so much when they first get out there; they’re nonstop mowing machines,” she said. “Grazing a couple of hours a day isn’t actually resting the pasture. It’s actually hurting it worse than leaving [horses or cattle] out for three days and then taking them off. They can eat 2 percent of their body weight in the first couple of hours.” An added problem with overgrazing is the potential for horses to get sand colic from inhaling sand into their stomachs when the plant material is gone, McGlynn added. “They will also begin eating poisonous weeds if that is all that is left in the pasture,” she said. “Livestock normally instinctually will avoid poisonous material, but if left in an enclosed area with no other choices, they will consume deadly weeds.” More information about stocking rates and

grazing recommendations is available through the local MSU Extension Service; call 758-5553.

Features editor Lynnette

Hintze may be reached at

758-4421 or by email at lhintze@


Grasshopper Insecticide Module

Printable version of Grasshopper Insecticide Module (PDF)


A seed treatment product for protection against damage from, or control of, listed

insects on barley, corn, cotton, cucurbit vegetables, legume vegetables (including

soybean), oilseed crops (black mustard seed, borage seed, crambe seed, field mustard

seed, flax seed, Indian mustard seed, Indian rapeseed seed, Rapeseed seed, and

safflower seed), potatoes, rice (dry-seeded), sorghum, sugarbeets, sunflower and wheat

Active Ingredient:

Thiamethoxam1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47.6%

Other Ingredients: 52.4%

Total: 100.0%

1CAS No. 153719-23-4

Cruiser 5FS contains 5 pounds thiamethoxam per gallon.



See additional precautionary statements and directions

for use in booklet.

EPA Reg. No. 100-941

EPA Est. 100-NE-001MHA Product of India

EPA Est. 46073-TN-003NTM Formulated in the USA

Superscript is the first three letters of batch code

on container.

SCP 941B-L3N 0909 301231

1 gallon

Net Contents


If inhaled • Move person to fresh air.

  • If person is not breathing, call 911 or an ambulance, then give

artificial respiration, preferably by mouth-to-mouth, if possible.

  • Call a poison control center or doctor for further treatment


If swallowed • Call a poison control center or doctor immediately for treatment


  • Have person sip a glass of water if able to swallow.
  • Do not induce vomiting unless told to do so by the poison control

center or doctor.

  • Do not give anything by mouth to an unconscious person.

If on skin or


  • Take off contaminated clothing.
  • Rinse skin immediately with plenty of water for 15-20 minutes.
  • Call a poison control center or doctor for treatment advice.

If in eyes • Hold eye open and rinse slowly and gently with water for 15-20


  • Remove contact lenses, if present, after the first 5 minutes, then

continue rinsing eye.

  • Call a poison control center or doctor for treatment advice.

Have the product container or label with you when calling a poison control center

or doctor, or going for treatment.


For 24-Hour Medical Emergency Assistance (Human or Animal)

or Chemical Emergency Assistance (Spill, Leak, Fire or Accident)




Hazards to Humans and Domestic Animals


Harmful if inhaled, swallowed, or absorbed through the skin. Causes moderate eye

irritation. Avoid breathing vapor or spray mist. Avoid contact with skin, eyes, or clothing.

Wash thoroughly with soap and water after handling, and before eating, drinking,

chewing gum, using tobacco, or using the toilet. Remove contaminated clothing and

wash before reuse.


Personal Protective Equipment (PPE)

Applicators, Other Handlers and Re-entry Workers Must Wear:

  • Long-sleeved shirt and long pants
  • Chemical-resistant gloves made of any waterproof material - Category A (e.g.,

natural rubber ≥ 14 mils)

  • Shoes plus socks

Multiple Task Workers must wear:

( Multiple task workers perform multiple tasks in one day such as mixing, bagging/

filling seed containers, product application, bag sewing, and clean up)

  • Chemical resistant gloves
  • Chemical-resistant coveralls over long sleeved shirt and long pants
  • Shoes plus socks

User Safety Requirements

Follow manufacturer’s instructions for cleaning/maintaining PPE. If no such instructions

exist for washables, use detergent and hot water. Keep and wash PPE separately from

other laundry.

Engineering Control Statements

When handlers use closed systems in a manner that meets the requirements listed in the

Worker Protection Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(4-6)],

the handler PPE requirements may be reduced or modified as specified in the WPS.

User Safety Recommendations

Users should:

  • Wash thoroughly with soap and water after handling.
  • Wash hands before eating, drinking, chewing gum, using tobacco, or using

the toilet.

  • Remove clothing immediately if pesticide gets inside. Then wash thoroughly

and put on clean clothing.

  • Remove PPE immediately after handling this product. Wash the outside of

gloves before removing. As soon as possible, wash thoroughly and change

into clean clothing.

Environmental Hazards

This product is toxic to wildlife and highly toxic to aquatic invertebrates.

Do not contaminate water when disposing of equipment wash water.



NOTICE: Read the entire Directions for Use and Conditions of Sale and Limitation

of Warranty and Liability before buying or using this product. If the terms are not

acceptable, return the product at once, unopened, and the purchase price will be


The Directions for Use of this product must be followed carefully. It is impossible to

eliminate all risks inherently associated with the use of this product. Crop injury, ineffectiveness

or other unintended consequences may result because of such factors as

manner of use or application, weather or crop conditions, presence of other materials

or other influencing factors in the use of the product, which are beyond the control

of SYNGENTA CROP PROTECTION, Inc. or Seller. To the extent permitted by applicable

law, Buyer and User agree to hold SYNGENTA and Seller harmless for any claims relating

to such factors.

SYNGENTA warrants that this product conforms to the chemical description on the label

and is reasonably fit for the purposes stated in the Directions for Use, subject to the

inherent risks referred to above, when used in accordance with directions under normal

use conditions. To the extent permitted by applicable law: (1) this warranty does not

extend to the use of the product contrary to label instructions, or under conditions


reasonably foreseeable to or beyond the control of Seller or SYNGENTA, and (2) Buyer

and User assume the risk of any such use. TO THE EXTENT PERMITTED BY APPLICABLE





To the extent permitted by applicable law, in no event shall SYNGENTA be liable for

any incidental, consequential or special damages resulting from the use or handling











SYNGENTA and Seller offer this product, and Buyer and User accept it, subject to the

foregoing Conditions of Sale and Limitation of Warranty and Liability, which may not

be modified except by written agreement signed by a duly authorized representative



It is a violation of Federal law to use this product in a manner inconsistent with its


Cruiser 5FS may be applied by closed or open system seed treatment application processes.

DO NOT apply more than 215 gallons of Cruiser 5FS per 8-hour day for seed

treatments utilizing a closed system. DO NOT apply more than 38 gallons of Cruiser 5FS

per 8-hour day for seed treatments utilizing an open system.


Use this product only in accordance with its labeling and with the Worker Protection

Standard, 40 CFR part 170. This Standard contains requirements for the protection

of agricultural workers on farms, forests, nurseries, and greenhouses, and handlers

of agricultural pesticides. It contains requirements for training, decontamination,

notification, and emergency assistance. It also contains specific instructions and

exceptions pertaining to the statements on this label about personal protective

equipment (PPE) and restricted-entry interval. The requirements in this box only

apply to uses of this product that are covered by the Worker Protection Standard.

Do not enter or allow worker entry into treated areas during the restricted-entry

interval (REI) of 12 hours. Exception: If the seed is treated with the product and the

treated seed is soil-injected or soil-incorporated, the Worker Protection Standard,

under certain circumstances, allows workers to enter the treated area if there will

be no contact with anything that has been treated.

PPE required for early entry to treated areas that is permitted under the Worker

Protection Standard and that involves contact with anything that has been treated,

such as plants, soil, or water is:

  • Coveralls
  • Chemical-resistant gloves made of any waterproof material - Category A (e.g.,

natural rubber ≥ 14 mils)

  • Shoes plus socks





Treatment of highly mechanically scarred or damaged seed, or seed known to be of low

vigor and poor quality, except for the purpose of curative control of existing disease

pests, may result in reduced germination and/or reduction of seed and seedling vigor.

Treat a small quantity of seed using equipment similar to that planned for treating the

total seed lot. Conduct germination tests on a small portion of seed before committing

the total seed lot to a selected seed treatment. Due to seed quality, crop or variety

sensitivity, and seed storage conditions beyond the control of Syngenta, no claims are

made to guarantee the germination of carry-over seed or propagating material for all

crop seed.


Cruiser 5FS is a systemic seed treatment insecticide belonging to the neonicotinoid class

of chemistry. Cruiser 5FS controls certain chewing and sucking insects through contact

and ingestion. The plant rapidly takes up the active ingredient in Cruiser 5FS as it starts

to emerge and establish. Cruiser 5FS is a selective seed treatment insecticide, and its

use is compatible with integrated pest management programs. The length of control

of the major insect pests will vary depending on the product use rate, insect pressure,

crop growth and maturity, and soil and environmental conditions. When rate ranges

are given, use the higher rate when insect pressure is expected to be high.


Important: Thoroughly shake the container of Cruiser 5FS prior to use.

Apply Cruiser 5FS as a water-based slurry utilizing standard slurry seed treatment

equipment which provides uniform seed coverage. Uneven or incomplete seed coverage

may not give the desired level of insect or disease control. Thoroughly mix the


amount of Cruiser 5FS into the required amount of water for the slurry

treater and dilution rate to be used. The typical density of Cruiser 5FS is 10.5 pounds

per gallon. Consult the manufacturer of the application equipment you plan to use

for suitability for this application and for instructions on operation and calibration of

the equipment.

  • Use an EPA-approved dye or colorant that imparts an unnatural color to the seed

as stated in 40 CFR 153.155 (c).

  • Allow seed to dry before bagging.
  • Store away from feed and foodstuffs.

Cruiser 5FS has been found to be compatible with some liquid inoculant products.

Cruiser 5FS may be mixed or applied sequentially with approved liquid inoculants.

Consult the maker of the liquid inoculants and a Syngenta Crop Protection representative

for directions before applying Cruiser 5FS with inoculants.


The Federal Seed Act requires that bags containing treated seeds shall be labeled with

the following statements:

  • This seed has been treated with Thiamethoxam insecticide.
  • Do not use for feed, food or oil purposes.
  • User is responsible for ensuring that the seed bag meets all requirements under

the Federal Seed Act.

In addition, the U.S. Environmental Protection Agency requires the following statements

on bags containing seeds treated with Cruiser 5FS (thiamethoxam):

  • Store away from food and feedstuffs.
  • Wear long-sleeved shirt, long pants and chemical-resistant gloves when handling

treated seed.

  • Treated seeds exposed on soil surface may be hazardous to wildlife. Cover or


treated seeds spilled during loading.

  • Dispose of all excess treated seed.
  • Do not contaminate water bodies when disposing of planting equipment wash


  • Dispose of seed packaging in accordance with local requirements.
  • In the event of crop failure or harvest of a crop grown from Cruiser 5FS treated

seed, the field may be replanted immediately to barley, canola, corn, cotton,

cucurbit vegetables, fruiting vegetables, legume vegetables, mint (peppermint

and spearmint), oil seed crops (black mustard seed, borage seed, crambe seed,

field mustard seed, flax seed, Indian mustard seed, Indian rapeseed seed, Rapeseed

seed, and safflower seed), rice, root vegetables, sorghum, strawberry, sunflowers,

tobacco, tuberous and corm vegetables and wheat. For any other crop, the minimum

plant back interval is 120 days from the date the Cruiser 5FS treated seed was

planted. A cover crop other than the crops listed above that is planted for erosion

control or soil improvement may be planted sooner than the 120 day interval;

however, the crop may not be grazed or harvested for food or feed.

  • Do not allow children, pets, or livestock to have access to treated seed.
  • Treated seed must be planted into the soil at a depth greater than 1 inch.
  • Dispose of all excess treated seed. Leftover treated seed may be doublesown

around the headland or buried away from water sources in accordance with

local requirements. Do not contaminate water bodies when disposing of planting

equipment washwaters.

  • With the exception of cotton and soybeans, do not make any soil or foliar application

of products containing thiamethoxam to crops grown from seed treated with

Cruiser (thiamethoxam).

  • Do not use at a rate that will result in more than 0.266 lb. thiamethoxam per acre

(120.66 grams a.i./A) per season.

Sunflower Seed Bags Only:

  • To protect the Preble’s Meadow Jumping Mouse, sunflower seed treated with

Cruiser 5FS may not be planted in Elbert or Weld Counties in Colorado. Treated

sunflower seed must be planted at a minimum depth of one inch.


Resistance Management

Some insect pests are known to develop resistance to products after repeated use.

Because resistance development cannot be predicted, the use of this product should

conform to sound resistance management strategies established for the crop and use

area. Syngenta encourages responsible product stewardship to ensure effective longterm

control of the insects on this label.

If resistance to this product develops in your area, this product, or other products with

a similar mode of action, may not provide adequate control. If poor performance cannot

be attributed to improper application or extreme weather conditions, a resistant

strain of insect may be present. If you experience difficulty with control and resistance

is a reasonable cause, immediately consult your local company representative or agricultural

advisor for the best alternative method of control for your area.

Cruiser 5FS contains a Group 4A insecticide (thiamethoxam, belonging to the neonicotinoid

class of chemistry). Insect biotypes with acquired or inherent resistance to Group

4A insecticides may eventually dominate the insect population if Group 4A insecticides

are used repeatedly as the predominant method of control for targeted species. This

may result in partial or total loss of control of those species by Cruiser 5FS or other

Group 4A insecticides.

In order to maintain susceptibility to this class of chemistry:

n Avoid using Group 4A insecticides exclusively for season long control of insect species

with more than one generation per crop season.

n For insect species with successive or overlapping generations, apply Cruiser 5 FS or

other Group 4A insecticides using a “treatment window” approach. A treatment

window is a period of time as defined by the stage of crop development and/or the

biology of the pests of concern. Within the treatment window, depending on the

length of residual activity, there may either be single or consecutive applications

(seed treatment, soil, foliar, unless otherwise stated) of the Group 4A insecticides. Do

not exceed the maximum Cruiser 5 FS allowed per growing season.

n Following a treatment window of Group 4A insecticides, rotate to a treatment window

of effective products with a different mode of action before making additional

applications of Group 4A insecticides.

n A treatment window rotation, along with other IPM practices for the crop and use

area, is considered an effective strategy for preventing or delaying a pest’s ability to

develop resistance to this class of chemistry.

n If resistance is suspected, do not reapply Cruiser 5FS or any other Group 4A


Other Insect Resistance Management (IRM) practices include:

n Incorporating IPM techniques into your insect control program.

n Monitoring treated insect populations for loss of field efficacy.

n Using tank-mixtures or premixes with insecticides from a different target site of

action group as long as the involved products are all registered for the same crop

outlet and effective rates are applied.

For additional information on Insect Resistance Management:

n Contact your local extension specialist, certified crop advisor and/or product manufacturer

for additional insect resistance management recommendations.

n Visit the Insecticide Resistance Action Committee (IRAC) on the web at:


Use Restrictions

Cruiser 5FS may be applied by closed or open system seed treatment application processes.

DO NOT apply more than 215 gallons of Cruiser 5FS per 8-hour day for seed

treatments utilizing a closed system. DO NOT apply more than 38 gallons of Cruiser 5FS

per 8-hour day for seed treatments utilizing an open system.

Commercial treatment of sorghum seed requires the use of a closed system.


To provide early season protection of seedlings against injury by bird cherry-oat aphids,

English grain aphid, greenbug, Hessian fly, Russian wheat aphid, and wireworm, and

to reduce potential spread of barley yellow dwarf virus due to aphid vectors, apply

Cruiser 5FS at 0.75-1.33 fluid ounces per 100 pounds of seed. At the high rate, Cruiser

5FS will reduce grasshopper damage in barley during the early season. For early season

wireworm protection, apply Cruiser 5FS at 0.19 to 0.25 fluid ounces per 100 pounds

of seed.

Corn (Field, Pop, Seed and Sweet Corn)

NOTE: If corn seed to be treated with Cruiser 5FS has existing infestations of stored

grain pests, fumigate the seed prior to treating with Cruiser 5FS and bagging.

NOTE: When treated according to the following directions for post-planting protection

against listed pests, Cruiser 5FS will also provide protection during post treatment storage

of the seed against damage from the following insects: Indian Meal Moth (Plodia

interpunctella), Lesser Grain Borer (Rhyzoperthadominica), Red Flour Beetle (Tribolium

castaneum), and Rice Weevil (Sitophilus oryza).

Consult your Syngenta Seed Treatment representative for specifics on slurry additives

to use during application of Cruiser 5FS.

Follow planter manufacturer instructions for use of talc, graphite, or other hopper box

additives at planting.

It is highly recommended to use registered seed treatment fungicides such as Apron XL®,

Dynasty® and Maxim® XL as the broad spectrum seed treatment fungicide with Cruiser

5FS applications on corn.

To provide early season protection of seedlings against injury by wireworm, seedcorn

maggot, southern corn leaf beetle, chinch bug, corn flea beetle, grape colaspis, white

grub (including Japanese beetle larvae, European Chafer larvae, true white grub,

annual white grub, May/June beetle larvae), black cutworm, thrips, southern green

stinkbug, seedcorn beetle, sugarcane beetle, and corn leaf aphid, apply Cruiser 5FS at

a rate to achieve between 0.250 and 0.80 milligrams thiamethoxam

per kernel (each

fluid ounce of Cruiser 5FS contains 17.7 grams thiamethoxam).

To provide corn rootworm (including Mexican, Northern, Southern, and Western corn

rootworm) and billbug protection, apply Cruiser 5FS at a rate to achieve 1.25 milligrams

thiamethoxam per kernel (each fluid ounce of Cruiser 5FS contains 17.7 grams


Cotton (Delinted Only)

To provide early season protection of seedlings against injury by cotton aphid, tobacco

thrips, western flower thrips, wireworm, and the suppression of cotton fleahopper and

plant bugs, apply Cruiser 5FS at a rate to achieve between 0.30 and 0.34 milligrams

thiamethoxam per seed (each fluid ounce of Cruiser 5FS contains 17.7 grams thiamethoxam).

Plant Cruiser 5FS-treated cotton seed based on specified planting dates and soil


made by your state agricultural extension agent. In areas that have a


of high thrips pressure or when cotton is grown in North Carolina or Virginia,

use Cruiser 5FS seed treatment followed by a foliar insecticide spray when cotton is

between the 1st and 3rd leaf stage.

Do not apply a neonicotinoid insecticide within 45 days of planting seed treated with

Cruiser 5FS.

Cucurbit Vegetable Group


Chinese Waxgourd

Citron Melon



Edible Gourd (includes hyotan, cucuzza, Chinese Okra, and hechima)

Momordica spp. (includes balsam apple, balsam pear, bitter melon, Chinese cucumber)

Muskmelon (includes true cantaloupe, cantaloupe, casaba, Crenshaw melon, golden

pershaw melon, honeydew melon, honey balls, mango melon,

Persian melon, pineapple melon, Santa Claus melon, and snake melon)


Summer Squash (includes crookneck squash, scallop squash, straightneck squash,


marrow, and zucchini)

Winter squash (includes butternut squash, calabaza, hubbard squash, acorn squash

and spaghetti squash)


To provide early season protection of seedlings against injury by Cucumber Beetle

apply Cruiser 5FS at a rate to achieve between 0.25 to 0.75 milligrams thiamethoxam

per seed* (each fluid ounce of Cruiser 5FS contains 17.7 grams of thiamethoxam).

*Based on an average range of 4,000 to 27,000 cucurbit seeds per pound.

Do not apply a neonicotinoid product (including Actara and Platinum) to cucurbits

previously treated with a Cruiser 5FS seed treatment.

Legume Vegetable Group

Bean (Lupinusspecies) (includes grain, sweet, white, white sweet lupin).

Bean (Phaseolus species) (includes field bean, kidney bean, lima bean, navy bean, runner

bean, snap bean, tepary bean, wax bean)

Bean (Vigna species) (includes adzuki bean, asparagus bean, blackeyed pea, catjang,

Chinese longbean, cowpea, Crowder pea, moth bean, mung bean, rice bean, southern

pea, urd bean, yardlong bean)

Broad bean (fava bean)

Chickpea (garbanzo bean)



Lablab bean (hyacinth bean)


Pea (Pisum species) (includes dwarf pea, edible-pod pea, English pea, field pea, garden

pea, green pea, snow pea, sugar snap pea)

Pigeon pea

Sword bean

To provide early season protection of seedlings against injury by aphids, bean leaf


leafhoppers, leaf miner, Mexican bean beetle, pea leaf weevil, plant leaf


seed corn maggot, thrips, white grub and wireworm, apply Cruiser 5FS at 1.28

fluid ounces per l00 pounds of seed.

It is highly recommended to use Cruiser 5FS with compatible and registered seed treatment

fungicides proven to control seed and seedling diseases. These fungicides must

show safety on treated seed, alone and in combination with Cruiser 5FS.


To provide early season protection of seedlings against injury by aphids, bean leaf

beetle, grape colaspis, leafhoppers, seedcorn maggot, threecornered alfalfa hopper,

thrips, white grubs, and wireworm, apply Cruiser 5FS at 1.28 fluid ounces per 100

pounds of seed. Alternatively, for those who wish to treat on a milligram per seed basis,

apply 0.0756 to 0.1512 mg. a.i. per seed.

It is highly recommended to use Cruiser 5FS with compatible and registered seed

treatment fungicides, like Apron XL and Maxim or ApronMAXX® brand formulations,

proven to control seed and seedling diseases. These fungicides must show safety on

treated seed, alone and in combination with Cruiser 5FS.

Do not apply a neonicotinoid insecticide within 45 days of planting seed treated with

Cruiser 5FS.

Oil Seed Crops (black mustard seed, borage seed, crambe seed, field mustard seed, flax

seed, Indian mustard seed, Indian rapeseed seed, Rapeseed seed, and safflower seed)

To provide early season protection of seedlings against injury by crucifer flea beetles

and wireworms, apply Cruiser 5FS at 10.24 fluid ounces per 100 pounds of seed.

It is highly recommended to use Cruiser 5FS with compatible and registered seed treatment

fungicides proven to control seed and seedling diseases. These fungicides must

show safety on treated seed, alone and in combination with Cruiser 5FS.


Note: Do not use, sell or distribute this product for use on potatoes, within, or into,

Nassau County or Suffolk County, New York.

Cruiser 5FS potato seed treatment is to be used as an integral part of a potato pest

management strategy.

This strategy includes the use of certified seed, proper crop rotation,

insect population thresholds, appropriate control measures, optimal harvest time

for tubers and proper handling of tubers without bruising. Consult your local agricultural

extension agent for more detailed information on insect management practices.

Application Procedure

Apply Cruiser 5FS using only Syngenta approved equipment that is designed to apply

liquid seed treatment products to potatoes. Follow the equipment instructions for

set-up and calibration. Cruiser 5FS may require dilution prior to atomization and

application to potatoes (see equipment use instructions). Ensure that spray nozzles

are properly hooded and shielded to prevent any spray from moving off target. Apply

Cruiser 5FS only in well-ventilated areas. Syngenta Crop Protection will not warranty

the field performance of Cruiser 5FS if the application is made through non-Syngenta

approved equipment. The mixture is applied as a fine spray over the cut or whole seed

tubers. The quantity of water and Cruiser 5FS volume is adjusted based on the amount

of seed moved under the hood. It is mandatory that the equipment be calibrated to

deliver a maximum of 4 fluid ounces of the mixture per 100 pounds of seed consistently.

Applying excess moisture may predispose the seed to rotting, resulting in poor

emergence and stand. Generally, liquid based fungicides (such as Maxim 4FS), can be

applied with Cruiser 5FS, however check compatibility of the fungicides with Cruiser

5FS before use. If inert dust (fir bark, talc, etc.) or a dust-based fungicide is used, apply

the Cruiser 5FS seed treatment before applying the dust.

It is highly recommended to use Cruiser 5FS with compatible and registered seed treatment

fungicides proven to control seed and seedling diseases. These fungicides must

show safety on treated seed.

Use Cruiser 5FS seed treatment to provide protection against injury from Colorado

potato beetles, flea beetles, green peach aphids, leafhoppers, leafminers, potato

aphids, psyllids, and whiteflies. Cruiser 5FS will also control wireworms that feed on

the seed piece.

The expected length of protection is dependent upon the rate used, soil and environmental

conditions and insect pressure. Select the appropriate Cruiser 5FS rate based

upon the history of pest pressure in the region and the length of the growing season.

In general, use the high rate of Cruiser 5FS in the following table for areas where

high insect pressure is expected. Consult your Syngenta representative for information


to your area or region.

Choose the appropriate Cruiser 5FS rate from the following chart, based

upon your seeding rate:

Potato Seeding Rate:

100 lbs. per Acre

Fluid Ounces of Cruiser 5FS

per 100 lbs. of Potato Seed Tubers

16-19 0.11-0.16

20-21 0.11-0.15

22-24 0.11-0.13

25-26 0.11-0.12

27-29 0.11

For seeding rates not covered by the above table, do not use a Cruiser 5FS rate that will

result in more than 0.125 pounds thiamethoxam per acre.

Treated Seed Storage

If the treated seed needs to be stored or held for a few days, make sure that there

is adequate cool air (60°F) movement through the pile of cut seed potatoes at relative

humidity of 85-90%. Do not pile cut and treated seeds above 6 feet in height.

Best results are obtained if potatoes are planted immediately after Cruiser 5FS seed


When transporting cut and Cruiser 5FS treated seed, make sure the seed

is covered.

Rice (dry-seeded use only)

To provide early season protection of seedlings against injury by grape colaspis rice

water weevil, chinchbugs, and thrips, apply Cruiser 5FS at a rate to achieve 0.03 milligrams

thiamethoxam per seed* (each fluid ounce of Cruiser 5FS contains 17.7 grams


Cruiser 5FS is not labeled for use in water seeded rice production.

Do not plant or sow Cruiser 5FS treated rice seed by aerial application equipment.

Do not use treated fields for the aquaculture of edible fish and crustacean.

*Not to exceed 120 lb. seed/Acre Seeding Rate.


To provide early season protection of seedlings against injury by chinch bug, corn leaf

aphid, fire ants, greenbug, seed corn maggot, stored grain insects, wireworm, and

yellow sugarcane aphid, apply Cruiser 5FS at 5.1 to 7.6 fluid ounces per 100 pounds of

seed or 0.062 to 0.093 milligrams thiamethoxam per seed* (each fluid ounce of Cruiser

5FS contains 17.7 grams of thiamethoxam).

*Based on an average of 14,500 sorghum seeds per pound.

Follow planter manufacturer instructions for use of talc or other hopper box additives

at planting.

A closed system must be used for commercial treatment of sorghum seed.


Cruiser 5FS is a seed treatment insecticide that provides early season protection against

injury from sugarbeet root maggot, leaf miners, wireworms, root aphids, white grubs,

spring tails, and beet leaf hopper. Cruiser 5FS protects sugarbeets from beet leaf hoppers

which may spread curly top virus. Thorough seed coverage will offer the best

protection of the seed from insect damage.

Apply Cruiser 5FS at 3.39 to 3.95 fl. oz. (equivalent to 60 to 70 grams a.i. of thiamethoxam

respectively) per unit of sugarbeet seed. A unit of sugarbeet seed is 100,000 seeds.

For protection against Pythium damping-off or Rhizoctonia species seed and seedling

diseases in sugarbeets, Cruiser 5FS may be applied with Apron XL® and Maxim 4 FS

fungicide seed treatments.

Cruiser 5FS may be applied in conjunction with polymers, pelleting materials and seed

coating materials that are approved as food-use inert ingredients by EPA and listed in

40 CFR 180.910-960. These materials must show safety on treated seed. The end product

that combines Cruiser 5FS with labeled fungicides must be tested for seed safety

without any detrimental effects on seed germination or plant stand establishment.

Pre-test the germination of a small sample of seed lot with Cruiser 5FS prior to large

scale commercial application.


To provide early season protection of sunflower seedlings against injury by flea beetle,

stored grain insects, sunflower beetle, and wireworm, apply Cruiser 5FS at 0.25 milligrams

thiamethoxam per seed (each fluid ounce of Cruiser 5FS contains 17.7 grams


It is highly recommended to use Cruiser 5FS with compatible and registered seed

treatment fungicides such as Apron XL®, Dynasty and Maxim 4FS which are proven to

control seed and seedling diseases.

Follow planter manufacturer instructions for use of talc or other hopper box additives

at planting.


To provide early season protection of seedlings against injury by bird cherry-oat aphids,

English grain aphid, greenbug, Hessian fly, and Russian wheat aphid, and to reduce

potential spread of barley yellow

dwarf virus due to aphid vectors, apply Cruiser 5FS at

0.75-1.33 fluid ounces per 100 pounds of seed. At the high rate, Cruiser 5FS will reduce

grasshopper damage in wheat during the early season. For early season wireworm protection,

apply Cruiser 5FS at 0.19 to 0.25 fluid ounces per 100 pounds of seed.


Do not contaminate water, food, or feed by storage, disposal, or cleaning of equipment.

Pesticide Storage

Store in a cool, dry place. Do not store above 90°F for extended periods.

For minor spills, leaks, etc., follow all precautions indicated on this label and clean up

immediately. Take special care to avoid contamination of equipment and facilities during

cleanup procedures and disposal of wastes.

Pesticide Disposal

Wastes resulting from the use of this product may be disposed of on site or at an

approved waste disposal facility. If these wastes cannot be used according to label

instructions, contact your State Pesticide or Environmental Control Agency or the

Hazardous Waste representative at the nearest EPA Regional Office for guidance in

proper disposal methods.

Container Handling (<5 gallons)

Non-refillable container. Do not reuse or refill this container. Triple rinse container (or

equivalent) promptly after emptying. Triple rinse as follows: empty the remaining contents

into application equipment or a mix tank and drain for 10 seconds after the flow

begins to drip. Fill the container 1/4 full with water and recap. Shake for 10 seconds.

Pour rinsate into application equipment or a mix tank or store rinsate for later use or

disposal. Drain for 10 seconds after the flow begins to drip. Repeat this procedure two

more times. Then offer for recycling if available or puncture and dispose of in a sanitary

landfill, or by incineration, or if allowed by state and local authorities, by burning. If

burned, stay out of smoke.

Container Handling (>5 gallons)

Non-refillable container. Do not reuse or refill this container. Triple rinse container

(or equivalent) promptly after emptying. Triple rinse as follows: empty the remaining

contents into application equipment or a mix tank and drain for 10 seconds after the

flow begins to drip. Fill the container 1/4 full with water. Replace and tighten closures.

Tip container on its side and roll it back and forth, ensuring at least one complete

revolution, for 30 seconds. Stand the container on its end and tip it back and forth

several times. Turn the container over onto its other side and tip it back and forth

several times. Empty the rinsate into application equipment or a mix tank or store

rinsate for later use and disposal. Repeat this procedure two more times. Then offer for

recycling if available or puncture and dispose of in a sanitary landfill, or by incineration,

or if allowed by state and local authorities, by burning. If burned, stay out of smoke.


Apron XL®, Cruiser®, Dynasty®, Maxim®, the Syngenta logo, and the CP FRAME

are trademarks of a Syngenta Group Company

U.S. Patent Nos. 5,852,012 and 6,022,871

©2009 Syngenta

For non-emergency (e.g., current product information), call

Syngenta Crop Protection at 1-800-334-9481.

Manufactured for:

Syngenta Crop Protection, Inc.

P.O. Box 18300

Greensboro, North Carolina 27419-8300

SCP 941B-L3N 0909


Grasshopper Management Module

Printable version of Grasshopper Management Module (PDF)

Managing Grasshoppers in Montana’s Rangeland and Cropland

Kevin Wanner, Assistant Professor, Entomology

Extension Specialist, Cropland Entomology

Department of Plant Sciences & Plant Pathology

Montana State University

Grasshoppers are common pests in Montana particularly in the central and eastern

regions. During 2010 - 2012, however, Montana has been facing a potential outbreak in

size not witnessed since the mid 1980’s. Managing grasshoppers during severe

outbreaks can be challenging. Ranches may have to consider alternative sources of

forage. At severe outbreak levels even repeated insecticide applications may not

salvage spring planted crops that are surrounded by grassland.

Rangeland: A total of 15-20 grasshopper nymphs per square yard is considered an

economic threshold for treatment. At these densities grasshoppers can result in 200 –

500 pounds of lost forage per acre of rangeland, depending on their duration and

conditions such as precipitation. Reduced Agent and Area Treatment strategies

(RAATs) can be used to control grasshoppers in rangeland. USDA research has

demonstrated that RAATs, a “skip pass” approach that also uses lower rates of

insecticide, can achieve 80 to 95% control (compared to 85-99% control with complete

blanket coverage at the full insecticide rate) at a lower cost. RAATs can be applied by

ground or air. The insecticide dimilin is most commonly used in large-scale grasshopper

spray operations. Dimilin is an insect growth regulator that is only effective against

juvenile insects that are molting. It is NOT effective against adult insects that no longer

molt, so timing is critical. Ideally the majority of grasshoppers should be in the 3rd instar

stage during treatment. Commercial honeybee colonies are often placed on ranchland.

A benefit of dimilin’s mode of action is that it is relatively safe to adult honeybees.

Spring Wheat: Grasshoppers are notorious for their ability to move into cropland from

surrounding grassy areas; cropland surrounded by grass is particularly at risk. The

treatment threshold for immature nymphs is different from thresholds for adults, and

also depends on whether the grasshoppers are within the field or around the edges.

The attached High Plains IPM Guide contains a table for thresholds in spring and winter

planted wheat. Crop protection is typically achieved by applying a boarder treatment of

insecticide to keep the grasshoppers from entering the crop. A border width of 150 feet

surrounding the crop may be adequate for control, but if grasshopper densities are high,

control may require up to a 1/4 mile border treatment where ground applied RAATs can

be considered. Under extreme pressure, control may be difficult and multiple border

treatments may be required. Border areas and crop margins should be monitored after

treatment to ensure that grasshoppers do not re-enter the field. Insecticide baits can

also be effectively used but USDA research has found that the effectiveness of

insecticidal baits can depend on grasshopper densities. Baits are not recommended

when grasshopper densities are higher than 30-40 per square yard.

Winter Wheat: Emerging winter wheat can be particularly vulnerable to damage by

grasshoppers. The larger adult stage grasshoppers are more difficult to control and can

move into emerging winter wheat fields from surrounding grassy areas. Treatment

thresholds for emerging winter wheat are lower, 3-7 per square yard within the field, or

11-20 per square yard around the margin probably requires treatment. Border

treatments applied as insecticidal sprays or seed treatments are the main

recommendation for protecting emerging winter wheat. Typically, spraying 150 feet

beyond the edge of the crop or 1-2 passes with treated seed around the perimeter of

the field is a sufficient border. Adult grasshoppers are more difficult to control, and the

higher end of the label rate is recommended. If grasshopper populations are very high

they are difficult to control, borders up to ¼ of a mile and repeated applications may

need to be considered. When applying border sprays, timing is important. Border sprays

beyond the edge of the crop need to be applied just before the wheat emerges; if it is

applied too early there may not be enough residual, it is applied too late, the damage

may have already occurred. Systemic seed treatments eliminate the timing concern, but

systemic insecticides require feeding to be active, but damage should be slowed

considerably. Commonly used insecticides are listed in the attached High Plains IPM

pest notes.

Treatment Thresholds: The number of insects that require treatment to prevent

economic damage can depend on factors such as the weather, crop health and crop

stage. For example, damage to rangeland by the same density of grasshoppers is more

severe during drought periods. Fewer grasshoppers can cause economic damage to

crops if they are feeding at sensitive developmental times. In some cases grasshoppers

in spring wheat crops can clip the developing heads, for example. One research study

reported that grasshoppers in lentil fields during flowering feed preferentially on the

flowers and developing pods, and a treatment threshold of only 2 per square yard was

recommended. Therefore treatment thresholds should be used as a sound guide

tempered with experience and observations of damage.

Additional information can be found on the USDA ARS Sidney grasshopper website,

http://www.sidney.ars.usda.gov/grasshopper/. The High Plains IPM Guide website,

http://wiki.bugwood.org/HPIPM, provides detailed information on sampling, thresholds

and management. RAATs brochures and management guides are provided as

attachments below.

Grasshopper Scouting Module

Printable version of Grasshopper Scouting Module (PDF)

Scouting Grasshoppers in Rangeland and Cropland

Kevin Wanner, Assistant Professor, Entomology

Extension Specialist, Cropland Entomology

Department of Plant Sciences & Plant Pathology

Montana State University

Vigilant scouting is important during grasshopper outbreaks. Egg hatch typically begins

sometime during May and can continue throughout the summer depending on the

weather and species of grasshopper. Small newly hatched grasshoppers are more

difficult to see due their size and require more careful attention. Grasshopper activity

occurs earlier and can be concentrated on warmer south facing slopes. As

grasshoppers get larger, particularly when winged adults are present, it can be more

difficult to estimate their numbers. Early in the morning when its cool grasshoppers are

less active and it can be easier to estimate their numbers. Later in the season, when

winter wheat is planted, most of the population can be winged adults and damaging

populations can fly in with little notice.

Grasshoppers tend to move into crops from surrounding grassland and damage is more

pronounced on crop edges. In some cases weeds can attract grasshoppers into fallow

fields before winter wheat is planted. Cropland intermixed with grassland, such as

Conservation Reserve Program (CRP) areas, is at higher risk of continued invasion and


The square foot method of surveying grasshoppers is used by USDA-APHIS to estimate

grasshopper densities in rangeland and produce hazard maps. With practice it is

considered accurate. The number of grasshoppers in a one square foot area is

estimated visually and randomly repeated 18 times while walking a transect. The total

number of grasshoppers is tallied and divided by two to give the number per square

yard. Alternatively, since it is difficult to estimate the number of grasshoppers per

square yard when population densities are high, sweep nets can be used. Four 180-

degree sweeps with a 15-inch diameter sweep net is considered equivalent to the

number of adult (or nymph) grasshoppers per square yard (NDSU Extension).

A total of 15-20 nymphs per square yard (correlates to about 10 adults) is considered

the economic threshold for rangeland. However, the actual threshold in can depend on

weather, the same number of grasshoppers can cause more damage to rangeland

during a dry period. A table with estimates of forage loss for different densities of

grasshoppers is provided below. Also provided below is a table with economic

thresholds for spring and fall planted grains. Again, actual damage can depend on crop

stage and condition and treatments may be required at lower numbers if there are signs

of economic damage.

Treatment thresholds for grasshoppers infesting grains (source: High Plains IPM Guide,


Table 1. Spring treatment guidelines for immature and adult grasshoppers in spring wheat (modified from

University of Minnesota information).

Immatures/yd2 Adults/yd2

Rating Margin Field Treat? Margin Field Treat?

Nonthreatening <25 <15 No <10 <3 No

Light 25-35 15-25 No 10-20 3-7

Yes, if there is potential for

head clipping

Threatening 50-75 30-45

Depends on prices,

crop condition

21-40 8-14

Yes, if there is potential for

head clipping

Severe >100 >60

Yes, monitor for


>41 >15

Yes, consider wider border

treatments and

Table 2. Fall treatment guidelines for adult grasshoppers in winter wheat (modified from University of Minnesota



Rating Margin Field Treat?

Nonthreatening <10 <3 No

Light 10-20 3-7 Yes

Threatening 21-40 8-14 Yes, consider wider border treatments

Severe >41 >15

Yes, use wider border treatments and

monitor for retreatment.

Bark Beetle

Printable version of Bark Beetle (PDF)

Bark Beetles

Are Your Trees at Risk?

Many species of bark beetles are causing widespread tree mortality throughout the Intermountain West. Although sometimes viewed by hu­mans as catastrophic, outbreaks of native forest insects are natu­ral events. Native insects and the plants they use for food and reproduction have evolved togeth­er. Unlike some introduced pests, native insects kill individual trees but do not threaten the ex­istence of an entire plant species. Native insect outbreaks only pose a problem when they con­flict with human resource values for a particular area (i.e., recreation, aesthetics, wildlife habitat, wood production, property values, etc). A tree in the wilderness is not subject to the same human values as a tree in your backyard.

Bark beetle populations have increased in forested areas of the western U.S. An abundance of larger-diameter trees in dense stands across broad landscapes and periodic drought have caused this increase in bark beetle populations.

Bark beetles causing widespread mortality in the forests of the Intermountain West are all native. Principal species include: mountain pine beetle, spruce beetle, Douglas-fir beetle, western pine beetle, fir engraver, western balsam bark beetle, pine engraver, and pinyon ips.

How can something so small

kill something so big?

These insects are small, brown and often difficult to see since most of their life is spent under the bark. Individual bark beetles are about the size of a grain of rice. In low numbers (latent populations) bark beetle populations are often associated with newly dead, dying or stressed trees caused by wind, snow, lightning, disease, feeding by other insects, or damage created by human activities. Single-tree and small-group mortality widely dispersed over the landscape is associated with these low level populations.

Beetle populations rise as susceptible hosts become more abundant. Disturbance (i.e. drought, windthrow, fire or insect defoliation) often initiates this population increase. Over large susceptible landscapes abundant tree mor­tality can occur, often affecting most, if not all, of the overstory trees.

When beetle populations are low, healthy and vigorous trees produce sufficient resinous pitch to drown or “pitch out” attacking adult in­sects. As trees become stressed, pitch production declines and the number of successful beetle at­tacks increases. During bark beetle outbreaks, however, even healthy trees are overwhelmed by many adult beetles “mass attacking” the tree. In addition to damage created by the beetles and their offspring, many beetles also harbor fun­gi that further limit the tree’s ability to transport needed nutrients and water.

DOUGLAS-FIR mortality (outbreak)

A Douglas-fir beetle

A “pitchout”

A “pitchout”

This publication is a collaborative effort between Forest Health Protection and National Forests to inform the public about tree-killing bark beetles, emphasising the northern Rocky Mountain and Intermountain regions (Utah, Ne­vada, western Wyoming, Idaho and Montana).

This information will assist you in identify­ing probable causes of tree mortality and determining your treatment options. It also lists contact information for your respective State and Federal Forest Health Specialists and other sources of information available to the public.

Fading trees attacked by bark beetles

Does this affect you? Look inside

Are my trees at risk?................................page 2

Have my trees been attacked?..........page 5

How to prevent Attacks.........................page 6

What is a bark beetle?............................page 8

What are land managers doing?......page 10

What causes similar attacks?............page 11

Who Should I Contact?............................page 12





Forest Health Protection – Intermountain West & Northern Rocky mountains

Are Your Trees atRisk to Bark Beetles?

WhatShould You Do?

Step 1: Identify Your Trees

The first step in determining whether or not your tree is susceptible to insect attack is to know what species of tree you have. The following lists are the principal evergreen species found in the Intermountain West and Northern Rocky Mountain regions.

Most pines have more than one needle attached to the tree together in a “bundle”. The number of needles per bundle is often important in determining the pine species.

Pines (native):


Needles are two per bundle, 1-3" long. The small ¾-2" long cones have very short stalks and stay attached to the tree for many years. Cones feel prickly.

Natural Range: ID, MT, WY, northern UT, spots along the Sierra Nevada Range in NV.

PINYON (Colorado and Singleleaf)

Colorado pinyon, found mainly in Utah have two, 1-2" long nee­dles per bundle. Singleleaf pinyon, found mainly in Nevada, have one sharp, rounded needle per bundle, >1" long. Cones are not spiny.

Natural Range: Colorado pinyon in UT; Singleleaf pinyon in NV, western edge of UT, scattered spots in southern ID.

SIngleleaf pinyon

Foliage with MALE and female CONES

Closed and open cones

Colorado pinyon

5-NEEDLED (e.g. limber, whitebark, and western white pines)

Several pine species with 5-needle bun­dles are native to the Intermountain West, but Limber is the more commonly planted species around homes. Needle length ranges from 1.5-4". Cones vary.

Natural Range: various throughout In­termountain West.

PONDEROSA (and Jeffrey)

Ponderosa needles are 2-3 to a bundle, ranging from 3-10" in length. Cones are 2-6" long and prickled. Jeffrey pine (3-needles) is found along the Sierra Nevada’s, overlapping with ponderosa pine’s broad range. Jeffrey generally has larger, stouter cones (5-9") with incurved spines (pokey ponderosa; gentle Jeffrey).

Natural Range: ID, MT, UT, spots in eastern NV and the Sierra Nevadas, isolated spots in WY.



oPEN PONDEROSA CONES 3 Forest Health Protection – Intermountain West & Northern Rocky mountains

Pines (exotic):

Austrian pine


These European pines have 2-needles per bundle, 1.5-3" and 3-6" longs, respectively. Scotch cones are smaller (1.5-2" long) than Aus­trian cones (2-3"). Cones of both species are not spiny (vs. ponderosa). Scotch pine is noted for the strong orange coloration of the bark.

Natural Range: As exotic species there is no native range but they can be found planted throughout the Intermountain West.

Scotch pine

Firs and spruce have only one needle (no ‘bundles’) but the shape of that needle can differ by tree species.

SPRUCES (native):

FIRS (native):

Subalpine fir

The short (1-1.5"), single, flat needles also have rounded tips but are thick at their base (vs. white fir). The dark purple cones (2.25-4" long) are borne upright on the up­per branches and are not dropped.

Natural Range: ID, western MT, west­ern WY, UT, spots in northern NV.

WHITe fir

The 2-3" long, single, flat needles nar­row to a stalk at their base and have round­ed tips (vs. sharp spruce or notched grand fir). The needles tend to curve upward, leav­ing few needles below the stem. The green­ish purple or yellow cones (3-5"), found in the upper branches, point up and are not dropped. Rather, they fall apart on the tree (vs. Douglas-fir cones that drop off).

Natural Range: UT, eastern NV, south­east corner of ID.

Engelmann and Blue Spruce

Single needles are square and sharp, leaving ‘bumps’ on the small twigs when they fall off. Blue spruce needles tend to be stiffer and sharper than Engelmann needles. Cones hang down, measuring 1- 2.5" in length for Engelmann and 2.5-4" for blue. In the wild, blue spruce prefers moist stream edges.

Natural Range: Engelmann spruce in ID, MT, WY, UT, and NV; blue spruce in UT and WY.




Upright cones stay on branches


The single, flat needles of grand fir are 1.25-2 inches long and distinguished by having a notched end. Needles tend to grow out to the sides giving the branch­lets a flattened appearance. Cones are also 2-4" long, green-brown in color, and extend up­ward.

Natu­ral Range: north­ern two-thirds of ID, north­west edge of MT.


Although not a true fir species, Douglas-fir is similar to other firs in having short (~1"), single, flat needles. Needles have rounded tips like white and subalpine fir, and are narrow at their base like white fir. However, the 3" long cones hang down. The cone scales have a distinct shape resembling the tail and back legs of a mouse.

Natural Range: ID, MT, WY, UT, and scat­tered spots in NV.

Young cones

Upright cones stay on branches




  • Kuhns, Michael. 1998. A guide to the trees of Utah and the Inter­mountain West. Utah State University Press, Logan, UT
  • National Audubon Society. 1996. Field Guide to North American Trees. A. A. Knopf, NY
  • Watts, Tom. 1985. Rocky Mountain Tree Finder. Nature Study Guild, Rochester, NY


Foliage and buds 4 Forest Health Protection – Intermountain West & Northern Rocky mountains

Step 2: Determine Your Trees’ Susceptibility

The susceptibility of an individual tree is of­ten described differently than the susceptibili­ty of a stand of trees. When there is a group of trees (a stand), a tree may be killed yet the over­all stand may look and function much as before. In an urban setting, however, individual trees are very important for aesthetic or other urban land­scape values.


Stressed trees produce less pitch reduc­ing the tree’s ability to prevent successful bark beetle attacks. Tree stress can be caused by hu­man activities (construction, paving, excavating, etc) or by natural causes (drought, wind, light­ning, other insects or disease agents etc.). Visual symptoms associat­ed with tree stress of­ten include sickly look­ing tree crowns.

Not all stressed trees are at­tacked by beetles, particular­ly when bark beetle populations are low. However, during bark beetle outbreaks, even healthy trees can be successfully attacked.


Dense stands composed of single-species, larger-diameter trees are most susceptible to bark beetle attacks; less-dense stands are gener­ally more vigorous and have higher pitch pro­duction. Stands of trees stressed by prolonged periods of drought or by defoliation, disease or other damage (windthrow, fire, etc) are especial­ly susceptible. Overall, stands that have mul­tiple age classes, species diversity and reduced tree densities are less susceptible to bark bee­tle attacks and associated impacts. Even dur­ing a bark beetle outbreak not all trees in a stand are killed.


Some bark beetles are species-specific tree killers. For instance, Douglas-fir beetle only at­tacks Douglas-fir trees. However, other spe­cies like mountain pine beetle will attack several species of pines.

Lodgepole, ponderosa, five-needle pines and other native and introduced pines: Most of our introduced and native western pines, with the exception of Jeffrey pine, are susceptible to mountain pine beetle attacks. Jeffrey pine is at­tacked by Jeffrey pine beetle which is very sim­ilar to mountain pine beetle. Pines susceptible to attack my mountain pine beetle are often >8 inches in diameter at breast height and weak­ened by drought. If populations of this insect are high, fire scorched trees are also suscepti­ble to attack. Windthrown or downed pine trees are rarely attacked by mountain pine beetle, but are often attacked by pine engraver. In standing trees pine engraver can be found attacking trees alone or in combination with other bark beetles, particularly during periods of drought. Pondero­sa pine (west of the Continental Divide) weak­ened by old age or other stressors (e.g. compe­tition, lightning, root disease) are susceptible to western pine beetle. Ponderosa pine in southern Utah and Nevada may be atacked by roundhead­ed pine beetle.

Singleleaf and Colorado pinyon pines: Al­though several species of bark beetles will attack pinyon pine, the most notable for causing wide­spread mortality is pinyon ips. Trees stressed by drought, defoliation and fire are very susceptible to attack. Prolonged periods of drought are of­ten the primary stress responsible for landscape level mortality associated with this bark beetle. However, slash piles created by thinning or con­struction of fuel breaks can increase local popu­lations of this insect to outbreak levels.

Engelmann and blue spruce: Engelmann spruce is the preferred host for spruce beetle; although during outbreaks of this insect blue spruce will also be attacked and killed. Spruce beetle prefers larger-diameter trees (>16 inch­es) but will kill trees as small as 5 inches in di­ameter during an outbreak. Spruce beetle popu­lations can build quickly in green downed trees resulting from windthrow or avalanche. If there is sufficient downed material allowing popula­tions to build to outbreak levels, emerging adult beetles will attack surrounding live trees.

Douglas-fir: Douglas-fir are attacked and killed by Douglas-fir beetle. The insects pre­fer trees >14 inches in diameter; especially those growing in dense stands or weakened by drought, fire, root disease or defoliation. Out­breaks of this insect are often associated with fire scorched trees or an abundance of recent downed green material. Smaller trees, <8 inch­es in diameter may be killed by Douglas-fir pole beetle.

White and grand fir: Fir engraver is the principle bark beetle associated with these tree species. Larger diameter trees are preferred, but during periods of stress caused by drought or de­foliation, trees as small as 3 inches in diameter are also killed. Attacks by this insect will not al­ways result in tree mortality; topkill and individ­ual branch mortality are also common.

Subalpine fir: Although fir engraver will also attack subalpine fir, particularly where it is intermixed with white and/or grand fir, most bark beetle attacks are associated with western balsam bark beetle. Populations of this insect are attracted to disease-stressed trees. Windthrown green trees are also preferred habitat for this bark beetle. Often a complex of organisms is re­sponsible for tree mortality including bark bee­tles, root disease, and drought. Landscape level mortality caused by this bark beetle usually cor­responds to extended periods of drought.

A dense stand with trees competing for resources

A thinned stand with a diversity of tree ages

Crown differences

between a healthy (left) and stressed (right) tree5 Forest Health Protection – Intermountain West & Northern Rocky mountains

Step 3: Determine if Your Trees Have Been Attacked

Many tree symptoms and associated signs of bark beetle attack are similar regardless of the tree or beetle species involved. Some of the most common symptoms and signs are de­scribed below.


As bark beetles bore into living trees, tree sap or pitch may be exuded from the entry hole as the tree attempts to drown the beetle. Beetles may push this pitch out their entry hole as they continue construction of their galleries, leav­ing small sticky tubes visible on the outside of the bark.

Not all tubes, however, indicate a successful attack. In some cases trees are successful in their defense and the beetles are flushed out. Unsuc­cessful-attack pitch tubes are often a light cream color. However, pitch tubes created when beetle attacks are successful are often reddish in color due to presence of sawdust in the pitch produced as beetles bore through the tree bark.

Attacks by mountain pine beetle on lodge­pole, ponderosa and other pines, or attacks by Jeffrey pine beetle on Jeffrey pine, are often de­tected early due to the presence of these highly visible tubes. Occasionally, trees produce little pitch or attacks are so high up on the tree bole that tubes are not readily visible.


Whether or not pitch tubes are visible, pres­ence of boring-created sawdust around the base of the tree or in bark crevices is a good indica­tor of successful beetle attack. Boring dust is the best indicator to use when trees are too stressed to produce pitch (dry attacks) or when attacks occur higher up on the tree bole. This is often the case for moun­tain pine beetle or pinyon ips at­tacks on pines in areas under drought (dry at­tacks) and for Douglas-fir bee­tle attacks on Douglas-fir and spruce beetle attack on Engle­mann spruce (high attacks).

Sawdust may also be created by carpen­ter ants and ambrosia beetles. However, both groups bore directly into the heartwood creating a white boring dust.


Woodpeck­ers and other birds foraging for beetle larvae and adult beetles will often flake off bark lay­ers, leaving piles of bark flakes around the base of infested trees. These bark flakes are particularly visible during the winter months against the white snow. Several species of pine and Engelmann spruce are frequently de­barked as these avian bark beetle predators feed.


Fading tree crowns are a good indicator of successful bark beetle attack. Depending on the tree species, needles will turn yellow, yellow­ish-green, sometimes orange and later red before they drop to the forest floor. Needle discolor­ation generally occurs within one year of suc­cessful attacks.

Not all tree species will fade at the same rate following bark beetle attack, nor will all trees of the same species fade simultaneously. The speed of fading depends partly on the health of the tree prior to attack, especially its water stress level. For example, pinyon pines attacked by pinyon ips during hot dry summers may fade within 3-4 months while subalpine fir attacked by western balsam bark beetle may fade in one year and healthy Douglas-fir attacked by Doug­las-fir beetle may take 2-3 years to complete­ly fade.

Trees with red needles indicate that beetles have emerged and the tree is no longer a threat to surrounding uninfested trees. However, trees with fading needles that appear yellowish-green or yellow usually have some life stages of the bark beetle present, preparing to emerge in the near future.


Trees may exude pitch for a number of rea­sons not related to bark beetles. Where pitch tubes are usually discrete, popcorn-shaped mass­es of pitch, pitch streamers are more of a long ‘drip’. Pitch streamers may be created when true firs are attacked by fir engraver or western bal­sam bark beetle, and occasional­ly when Douglas-fir are attacked by Douglas-fir bee­tle. Although pitch streamers can be a sign of bark bee­tles, they should not be used as the only indicator of a successful bark beetle attack.


Removing the outer bark in areas of the tree where beetles have attacked will: confirm an at­tack, determine success or failure of the attack, and identify which beetle is responsible for the attack. Each beetle species or species group (i.e. Ips species) has a signature gallery pattern. These specific patterns are described in ‘What is a bark beetle’ (pg 8+). Within successful galler­ies you will often find adult beetles laying eggs in the gallery or larvae feeding or pupating. Unsuc­cessful attacks will have incom­plete galleries and often have galleries filled with pitch. How­ever during initial stages of a bark beetle attack, the galleries are also incomplete.

Red boring dust

on tree bark

Woodpecker feeding

Pitch streaming

Pitch tubes

stages of crown fade

Photo by W. Ciesla, Forest Health International

UNSUCCESSFUL GALLERY FILLED WITH PITCH 6 Forest Health Protection – Intermountain West & Northern Rocky mountains

Step 5: How to prevent Bark Beetle attacks

Preventing successful bark beetle attacks is key to protecting uninfested trees. Once insects have entered the bark there are no effective treat­ments to keep the tree alive. Steps you can take to prevent successful attacks on uninfested trees include:

  1. Remove all currently infested trees.
  2. Always remove, chip or burn recentl­windthrown trees or wood debris that’s >4 inches in diameter. Larger pieces of wood provide a more abundant food source for the beetles and produce more of the adults.
  3. Avoid damaging the bark or root system of standing green trees.
  4. Initiate thinning treatments to reduce stand densities, leaving a mix of age classes, tree species or both. Thin­ning reduc­es competi­tion between trees for lim­ited sun, water and nutrients. Re­maining trees are better able to produce pitch used in the trees defense against bark beetle attacks. A mix of age classes and tree species reduces the stands susceptibility to attack and impacts caused by bark beetle outbreaks. Contact your local State Forester’s office for assis­tance (pg. 12).
  5. Increase age and species diversity to enhance stand resistance to bark beetle attacks, and reduce the effects of tree mortality when at­tacks occur.
  6. Preventative insecticide treatments offer ex­cellent single-tree protection if applied prop­erly. Several formulations of carbaryl and pyrethroids are registered for bark beetle ap­plications. There are no effective or registered insecticides for some species of bark beetles such as fir engraver and western balsam bark beetle.

Step 4: How to Treat Trees That Have Been Attacked

Signs of successful bark beetle attack (bor­ing dust, pitch tubes, etc) that occur on more than half of the tree’s circumference general­ly indicate imminent tree mortality. There are no chemical insecticides shown to prevent tree mortality once adult beetles have penetrated the outer bark. If less than 50 percent of the tree circumference is infested (strip attack), preven­tive treatments may successfully protect the un­infested portion of the tree bole.

Sanitation practices to suppress popula­tions include removing the infested tree, de­barking the tree bole, and chipping or burn­ing the wood. Cutting the tree into firewood lengths may not result in bark beetle mortali­ty, especially if the material is shaded. Howev­er, other treatments may help dry out material before beetles can mature. For example, infest­ed lengths of wood can be moved to sunny lo­cations and rotated weekly, or the bark can be fully or partially removed to expose the phloem to open air. Use of plastic wrapping or tarps over infested material is not a recommended treatment method.

Infested material needs to be addressed before new beetle emerge. Because some bark beetle species have multiple generations per year (i.e. western pine beetle and ips spe­cies) you may have little time for treatment. For example, 35 days may be all that’s re­quired for pinyon ips or pine engraver to complete their lifecycle.

When needles turn reddish-brown in color, most adult beetles have left the tree. Spruce beetle may be the exception, since a portion of the population requires two years to complete its life cycle. There may be oth­er beetles, borers and larvae in the tree but these are usually secondary insects or in­sect predators and pose little threat to residu­al green trees.

Trees with reddish colored needles or those completely void of needles can be used for firewood or left standing as wildlife trees. However, dead trees that present a hazard to existing structures or could endanger humans should be removed before they fall.

Chipping slash

If enhancing wildlife habitat interests you, con­sider keeping dead trees on your forested lands. Standing dead trees in a forest are called “snags” and many species of wildlife depend on snags for their survival.

Owls, hawks, and eagles use snags to perch and to support their nests. Cavity nesters such as woodpeckers, mountain bluebirds, and chickadees nest in the snag cavities.

Chipmunks, squirrels, and other mammals use snags as homes. Bats use areas under loose bark for roosting. Fungi, mosses, and lichens common­ly grow in the decaying wood of a snag.

Insects chew through the decaying wood, cre­ating tunnels and chambers. Moths and ladybird beetles, and many species of reptiles and amphib­ians, hide under the bark of snags.

With so many animals and plants living on and in a dead tree, other animals frequently come there to feed. For example, many species of wood­peckers depend on snags to provide insect larvae for food.

If a tree on your private land does not have the potential to endanger persons or property, please consider leaving it standing for our animal friends!

Thinned pine stand

Dead Trees

are “Home”

to Many


Creatures 7 Forest Health Protection – Intermountain West & Northern Rocky mountains

Chemical Treatments


  • MCH for Douglas-fir beetle: MCH (one-methy-cyclo-hex-3-one) is a chemical used by Douglas-fir beetle to communicate. This pheromone tells dispersing adult beetles that a tree is fully occupied and to look elsewhere for another host tree. The pheromone has been commercially synthesized and is available in small bubble caps that are easily stapled to the tree bole prior to beetle flight in early spring. These are slow release cap­sules that distribute the repellant pheromone over the flight period. Application rates should be 30-40 bubble caps per acre for area protection or 2+ caps per tree for single tree protection. See ‘Using MCH to Protect Tees and Stands from Douglas-fir beetle In­festation’ at http://www.fs.fed.us/r1-r4/spf/fhp/publications/MCH_brochure/MCH_online. pdf.
  • VERBENONE for mountain pine beetle: Verbenone (4,6,6-trimethylbicyclo[3.1.1]- hept-3-en-2-one) is the repellant pheromone for mountain pine beetle. This pheromone is also available commercially. Recommended dosage is 2+ pouches per tree for indi­vidual-tree protection, or in lodgepole pine, 20-40 pouches per acre for area treatment. Application prior to summer beetle emergence is necessary. Verbenone treatments are generally deployed in sites where insecticide application is not feasible. Effectiveness of the verbenone treatment varies depending on beetle population pressure, number of currently infested trees and other stand conditions. Annual removal, debarking or chip­ping of infested trees from the verbenone treated site is recommended. Research stud­ies are currently being conducted to improve the formulation by adding additional re­pellents to enhance treatment effectiveness.
  • Contact your e forest health specialist(page 12) for technical ad­vice on administration of these treatments and to determine if financial assistance is available.


  • Carbaryl – Flowable formulations of this insecticide are registered and effective for several bark beetle species (mountain pine beetle, Jeffrey pine beetle, western pine beetle, spruce beetle, and ips species). These are preventative sprays applied to the tree bole before trees become infested. Generally, insecticide treatments are only used on high-value trees and applied by licensed pesticide applicators. All tree bole surfaces must be treated to the point of run-off including the trees root collar. Spray height var­ies from 30-50 feet depending on tree height. Although the label indicates annual treat­ments are necessary, research has shown that properly treated trees remain protect­ed for 18-24 months. our State orest Health Specialist can assist you with treatment recommendations (page 12), and your State Department of Agriculture can assist in finding licensed pesticide applicators.
  • Other Insecticides - Although registered pyrethroids are effective preventative treat­ments for some species of bark beetles, applications are generally required annually.
  • Systemic Insecticide treatments – Systemic insecticides applied as a soil drench or delivered directly into the trees bole have not been shown to be effective against most of our western bark beetles. However, with some exceptions, tree injections using em­amectin benzoate may be effective against western pine beetle.

Pesticides used improperly can be injurious to humans, animals, and plants. Fol­low directions and read all precautions on the label. Consult your local county agricul­ture agent or State extension agent about restrictions and registered uses of particular pesticides.

MCH bubble cap

Verbenone pouch

Carbaryl application8 Forest Health Protection – Intermountain West & Northern Rocky mountains

WhatisaBark Beetle?

Bark beetles are small (≤1/4-inch long), hard bodied beetles that bore through the tree’s protective outer bark to lay their eggs in the living tissue underneath. Following adult egg-laying, the develop­ing larvae feed on this living tissue, further disrupting nutrient and water flow within the tree. Egg-laying and feeding galleries created by adult beetles and their larvae are unique for each species of beetle. Note that all bark beetle species described in this brochure are native insects.

Feeding larvae girdling tree

Mountain (and jeffrey) pine beetleS

Mountain pine beetle attacks most native and introduced pine species, except Jeffrey pine which is attacked by the very simi­lar Jeffrey pine beetle. Occasionally spruce are attacked, especially when mixed in a stand of host pines. Periodic mountain pine beetle out­breaks kill millions of pine trees throughout for­ests of western North America, making it one of the West’s most important bark beetles.

Beetle populations can reach outbreak pro­portions on susceptible landscapes during pro­longed periods of drought. Trees as small as 4-5 inches in diameter may be attacked and killed during outbreaks, although few to no adult bee­tles are produced. In times of low populations, attacks are confined to trees stressed from over­crowding, disease, defoliation, injury or old age. Downed hosts trees are rarely attacked by this insect.

Successfully attacked trees can have faded foliage as early as 4-5 months following infesta­tion, but generally fade 8-10 months following attack. Emerging adult beetles often begin dis­persing in late June to mid-July with adult flight continuing into September. However, these dates may vary depend on elevation, latitude, and lo­cal weather.

Adult beetles are brown to black in color and about 1/4 inch long with a rounded rear end. The larvae are yellowish white, legless grubs with black heads found within feeding tunnels under the outer bark. The egg-laying gallery created by the female adult beetle is straight and vertical on the tree bole. Gallery length can be 3 feet or more. At the bottom of the gallery is a distinctive “J” shaped crook. Eggs are laid alter­nately along the walls of the egg laying gallery.

Douglas-fir beetle

The only host for this bark beetle is Douglas-fir. Outbreaks are often associated with trees that are windthrown, fire scorched or defoliated. Unlike mountain pine beetle, outbreaks are generally confined to smaller areas with tree mortality generally rang­ing from a few to several hundred trees. Out­breaks are also often of shorter duration.

Although the beetle prefers larger host trees, it will attack and kill trees of many sizes. Trees <8 inches in diameter, however, are more com­monly at­tacked by Dougles-fir pole beetle. Dense stands of suscep­tible hosts spread over large land­scapes can result in widespread mortality.

Adult dispersal can occur from April through August depending on the site. Approximately 10 months after a suc­cessful mass attack, the tree’s needles begin to turn yellowish-green. During drought periods, fading can occur within 4-5 months.

Adults are brown to black and about 1/4 inch long with a rounded back end. Larvae are whitish, legless grubs with brown heads found in the galleries under the bark. The egg-laying gallery is usually about 8-10 inches long with a small angled “J” at the bottom portion of the gallery. The female lays several eggs along one side of the egg gallery before alternating to the opposite side of the gallery to lay several more, repeating the pattern several times.

Spruce Beetle

This bark beetle prefers Engelmann spruce, but will attack blue spruce when populations reach outbreak levels. Even during out­breaks, most blue spruce will survive. Outbreaks typically be­gin in ar­eas of wind-thrown trees, with adult beetles dis­persing to ad­jacent stand­ing trees. Widespread tree mortality can occur in En­gelmann spruce dominated landscapes. Infested trees fade (needles turn a yellowish-green) ap­proximately one year following mass attacks.

Spruce beetle can have a one or two-year life cycle. Adult beetles are 1/4-inch long, with reddish-brown or black wing covers. Larvae are yellowish white, legless grubs found under the outer bark. Spruce beetle egg galleries average 6-8 inches in length. Eggs are laid alternately along the gallery with larvae feeding gregarious­ly outward in all directions.

Mountain pine beetle


Spruce beetle galleries

Douglas-fir beetle galleries 9 Forest Health Protection – Intermountain West & Northern Rocky mountains


Although in the same group as the previous beetles, this native bark beetle tends to be less aggressive, generally attacking individual large, overmature ponderosa pines. Often these trees have been hit by lightning, have root disease, suffer from drought, or are otherwise stressed. However, they can cause patches of mortality in dense stands of medium-sized trees. During periods of prolonged drought, insect population can reach outbreak levels. Note that this beetle is not found east of the Continental Divide.

Adult beetles are dark brown to black and slightly smaller than some of the other bark beetles, ranging from about 1/8-1/5 inch long. Adults create a distinctive random serpentine egg gallery pattern under the bark. Larval galler­ies are rarely seen since larvae inhabit the thick, corky outer bark during most of the year.

This bark beetle species can produce two generations per year depending upon weather conditions. Beetles begin attacks in late spring, continuing until colder weather inhibits further development and spread. Trees attacked in early summer may fade before adult beetles emerge in the fall. Trees attacked in September by the sec­ond generation of beetles, usually fade the fol­lowing spring.


Most native bark bee­tles in the “ips” group are not aggressive tree killers. Rather, they tend to at­tack recently dead, damaged, or stressed trees. Pinyon pine trees, however, are often found in areas prone to water and heat stress. During drought periods, adult beetles overwhelm weak­ened trees 3 inches in diameter and larger. Out­breaks can affect large landscapes of suscepti­ble hosts.

Adult beetle attacks begin early in the spring and can continue through early fall. Two or more generations are produced annually. Be­cause of multiple generations, the insect can spread rapidly when conditions are favorable.

Pinyon ips are about 1/8-inch long, with an indented backside (versus a rounded back end) and small spines that are typical of all Ips spe­cies. Gallery patterns of most ips are similar, of­ten a Y- or H-shape, with a larger mating cham­ber from which the separate egg galleries ra­diate. Larva and beetles overwin­ter under the bark where they con­sume large patches of inner bark. Wood bor­ers often in­fest trees af­ter pinyon ips attacks.


other ips species

Pine engraver (ips group) is most problematic in ponderosa and Jeffrey pine, although almost any pine species can be a host. Stress due to drought, fire, or other damage increases a tree’s susceptibly to attack. However, recently cut logs (slash) or wind-thrown trees are preferred. If not properly managed, population levels can build in fresh slash or downed material in the spring. This preferred habitat can create localized outbreaks, killing patches of standing smaller diameter sized trees or topkill on large diameter hosts.

Pine engraver beetle adults are about 1/8- inch long, with anspiney, indented backside. The adults produce they typical Y- or H-shaped galleries. Beetles usually overwinter in the duff layer but may overwinter in previously attacked logs or trees. Once spring temperatures reach 65°F, beetles begin to fly until cold fall weather stops dispersal.

Pondero­sa pine is also a preferred host for several oth­er ips beetles. The Arizona fivespinedips, found in south­ern Utah and the southeast por­tion of Nevada, can be fairly ag­gressive, attack­ing large trees over a wide area when drought conditions devel­op. The emargin­ated ips and six­spinedips, both larger engravers about 1/4-inch long, have caused tree mortality during drought years in eastern Montana. Many other species of ips at­tack pines and spruce. Ips species can be identi­fied by the number and shape of spines on their backsides, and their typical Y- or H-shaped gal­leries containing little frass. Wood borers often infest trees following ips attacks.


Western pine beetle serpentine egg galleries

Typical ips gallery

H-shaped gallery typical of ips 10 Forest Health Protection – Intermountain West & Northern Rocky mountains


This species attacks true firs (less often subalpine fir); Douglas-fir is not a true fir. The insect causes topkill, branch kill and tree mortality, attacking trees >3 inches in diameter. Tree needles generally turn yellow-red within 3-5 months. Evidence of attack be­fore trees fade is of­ten hard to detect; entrance holes are with­out pitch tubes and in the In­termoun­tain West, pitch streamers may or may not be present. Boring dust in bark crevices and around the base of tree or fading needles are more reli­able signs of successful attacks.

Adult beetles are about 1/8-inch long, black, with a truncated, spineless back end. The egg galleries run horizontally across the stem, aver­aging 6 inches in length. Larvae mines radiate vertically out from the egg gallery. Following at­tack, a fungus associated with the beetle stains the surrounding attacked area a yellow-brown color. Larvae overwinter under the outer bark with adult beetles emerging in June. Adult flight may occur from June-September. The life cycle is usually one year.


This species is associ­ated with bark beetle attacks on subalpine fir. Adults are about 1/8 inch long, and brown or black in color. There is a distinctive hairy patch (toupee-like) on the head of the female beetle. The gallery pattern is star shaped.

External evidence of successful attacks by western balsam bark beetle is often diffi­cult to detect. Entrance holes are often high on the trunk, but boring dust may be visible in bark crevices in late summer. Pitch flow may also be observed with fine boring dust present in the pitch if attacks were successful. Needles on successfully attacked trees turn yellowish-red within a year and can remain bright red for several years after death. Outbreaks of this in­sect are often initiated by prolonged drought and windthrow.

Generally a two-year life cycle is observed, but one-year life cycles are also possible. Two peak flights of adult beetles occur, late June/ear­ly July and late July/early August.

Western balsam bark beetle and galleries

fir engraver GALLERies

Challenges of aBark Beetle Outbreak-

Whatare Land Managers Doing?

Federal and State Land Managers

Developing management strategies to miti­gate bark beetle effects is a difficult challenge for Federal and State resource managers. For­est health specialists understand tree and stand characteristics that increase susceptibility for many of the bark beetle species discussed in this brochure and, in conjunction with resource man­agers, develop silvicultural treatments to reduce impacts caused by these insects. Regardless of the treatment bark beetle outbreaks are not pre­ventable; only their impacts can be reduced.

Land management planning is required for all Federal and State administered lands. Public involvement is invited and encouraged as part of the Federal planning efforts. Some areas on Fed­eral lands are excluded or restricted from vege­tation management activities (i.e. wilderness and roadless areas). Resource tools to manage bark beetle populations within these areas are often not available.

Where vegetation management treatments are permitted, Federal and State resource man­agers can develop treatments to reduce stand densities, increase tree species and age diversity, and remove bark beetle-infested trees.

Often resource managers develop treatments to reduce bark beetle impacts within the treated landscapes. Removing infested trees as a stand-alone treatment may help suppress develop­ing populations of bark beetles. But, if adjacent stands contain beetle populations and the treat­ed sites remain susceptible, bark beetles may re-infest the treated area. Protection of individual, high-value trees can be accomplished with in­secticide and pheromone treatments.

Private Landowners

Treatments developed for private lands will vary depending on the objectives of individual owners. Some may choose to do nothing and let nature take its course; others may prefer a more aggressive approach and initiate treatment strat­egies similar to those described for Federal and State land managers.

Land owners who do no treatment and choose to leave infested trees or stands suscep­tible to bark beetles could affect residual trees on adjacent ownerships where treatments have occurred. Mixed ownerships in close proximi­ty to one another with various objectives com­plicate developing effective treatment strate­gies. A number of factors can affect this decision process including: treatment options may not be available to all ownerships, treatment economics may effect implementation and site conditions may be too difficult to treat (eg. steep slopes).

Fortunately, there are effective single-tree treatments available for high-value trees. Repel­lent pheromones and preventative insecticides are treatment options available to private land­owners. These single tree or small area treat­ments will require continuous applications until bark beetle populations collapse. 11 Forest Health Protection – Intermountain West & Northern Rocky mountains


that cause damage similar to that of bark beetles

Other insects or animals can cause damage to trees that may resemble bark beetle activity. We have listed a few of these to help you discern between bark beetle attacks and activity from other agents.


Other insects and diseases can cause dam­age to the needles of trees that may look like bark beetle activity from a distance.

Western spruce budworm (Choristoneuraoccidentalis Freeman) (WSBW) and Douglas-fir tussock moth (DFTM) (Orgyiapseudotsuga­ta (McDunnough)) are two of our most conspic­uous foliage feeding insects. Larvae of both of these moths feed on Douglas-fir, all true firs, and spruce (also larch for western spruce budworm).

Although feeding larvae prefer new nee­dles, older needles are often consumed during outbreaks. Trees often appear reddish-orange in color as partially consumed needles fade. Branch tips will be bare and often covered with silk webbing and dead needles.

Contact your local State forest health spe­cialist for assistance with identification and sup­pression treatments of defoliators.

AmbrosiabeetleS are very small, creat­ing multiple pin holes in wood where they culti­vate a fungi (am­brosia) that they feed on.

Bark beetles have often left their host tree by the time you see red needles. In­spection of the dead tree may reveal in­sects that were not di­rectly respon­sible for the tree’s death.

Most of­ten confused with bark beetles are the metal­lic and long­horn woodborers. Wood borers are much larger than bark beetles. These borers feed on the phloem just as bark beetles do; however, their galleries lack a distinct shape. While developing, the lar­va may drill large oval or round holes into the wood. Depending on the species, their life cycle may take from one to over ten years to complete.

landscape damage

Woodwasp larva make large holes in dead wood similar to wood borers but the larva do not feed in the phloem.

A bark beetle (left) and metalic wood borer (right)

WSBW larvae have paired white spots on both sides of each body segment

Older dftm larva with “tussocks” and “horns”

Even woodpeckers (sapsuckers) can make holes in the bark that may look like bark beetle entrance/exit holes.

Longhorn wood borer

Metallic wood borer

Tree crown damage from feeding larvae



The Role

of Fire

Trees with red needles are more flamma­ble than live trees. However, once the needles have fallen, standing dead trees no longer increase wildfire risk. As the trees drop to the ground, the addition of downed woody fuels does increase fire intensity and severity.

Fire is a natural part of the ecosystem. Vegetation in the West has evolved in fire driven ecosystems and in many cases relies on fire for sustainability and forest health.

However, wildfires around human habi­tation are often not desirable. Research in­dicates that the most critical factors to mit­igate fire loss around structures are the construction materials used, and the type and distance of vegetation around the struc­ture.

FIREWISE™ is a multi-agency, non-profit program designed to assist individuals with wildfire survivability to reduce struc­ture losses. The program encourages de­veloping a “defensible space” around your home. Information on how to reduce loss­es to wildfire can be found on a variety of FIREWISE™ websites.

General recommendations to reduce structure losses include:

  1. Roofs should be constructed of non-flammable material.
  2. Enclose places on structures where fire embers can accumulate.
  3. Thin dense vegetation around the home.
  4. Remove brush or dried grasses adjacent to the home.
  5. Landscape with fire resistant plants.
  6. Keep firewood and propane tanks at a safe distance from the home.

Firefighter safety is a primary consider­ation in any fire incident. Creating “defen­sible space” will enhance opportunities for firefighters to safely protect your home.

For additional information on measures to protect your home, visit the FIREWISE™

contact your local fire department.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office Of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

The use of trade or firm names in this publication

is for reader information and does not imply

endorsement by the U.S. Department of Agriculture

of any product or service.

06/09 12 Forest Health Protection – Intermountain West & Northern Rocky mountains

Douglas Fir Tussock Moth

Printable version of Douglas Fir Tussock Moth (PDF)

Douglas-fir Tussock Moths

5.542 Fact Sheet No. Insect Series|Trees and Shrubs

by W. Cranshaw, I. Aguayo, and D. Leatherman*

Caterpillars of the Douglas-fir tussock moth, Orgyiapseudotsugata(McDunnough), chew the needles of spruces, Douglas fir and true firs. During outbreaks they may cause extensive defoliation, with injury typically first concentrated at the top of the tree. Older caterpillars may rapidly defoliate a tree and tops may be killed, sometimes after only a single season of severe injury. Following repeated attacks over several seasons whole trees may die or be weakened to the point of inviting fatal attacks by bark beetles.

Problems in urban forests along the Colorado Front Range primarily involve blue spruce. Historically, outbreaks in our native forests have involved Douglas fir and been infrequent, although lately, probably due to the accumulated effects of fire suppression practices, these have occurred more often. The insect is much more important as a forest pest in the northwestern United States.

Douglas-fir tussock moth caterpillars also can cause problems because the larval hairs can be irritating and are capable of producing a painful rash. Individual reactions to the hairs are highly variable with some people reacting strongly following exposure while others have little reaction.


Young tussock moth caterpillars are blackish with long body hairs, producing brightly colored tufts of hair as they grow larger. A mature larva is 1.2-1.4 inches long, with a gray to brown body and shiny black head. Two long tufts of black hairs project forward from the head, and a similar tuft projects backward from the rear of the body. Dense, light brown patches of hairs and red spots occur on the first four and the last abdominal segment and there is an orange stripe on each side.

The cocoon surrounding the pupal stage is brownish gray and covered with hairs from the body of the larva. Cocoons usually are attached to foliage but may be found on tree trunks, rock, or other objects in the vicinity of a previously infested tree.

The adult males are moths with rusty-colored forewings and gray-brown hind wings, with a wing-span of about one inch. Females are thick-bodied and wingless, found in close association with the spot where they earlier pupated.

The egg mass, laid on the pupal cocoon of the female, contains about 300 white spherical eggs laid in several layers. The entire mass is covered with a frothy substance that is intermixed with body hairs of the mother. Movement of Douglas-fir tussock moth into new locations around the state sometimes result from humans incidentally moving construction materials or other items that have attached egg masses.

Life History and Habits

Douglas-fir tussock moth spends the winter as an egg within the egg mass. Eggs hatch in the spring, often in late May, typically following bud break. The small, hairy caterpillars migrate, moving to the new growth but also often dispersing upwards in the trees. This latter habit allows some of the caterpillars to be disperse by winds, which will carry the small, hairy caterpillars. Since the adult female moths do not fly, wind-blown movement of young larvae is an important means of initiating new infestations.

The caterpillars first feed solely on the newer foliage, and partially eaten needles may wilt and turn brown. Later, the older caterpillars will move to older needles as

Quick Facts

  • Douglas-fir tussock moth caterpillars feed on needles of spruces, Douglas-fir and true firs.
  • Sporadically outbreaks of Douglas-fir tussock moth occur in several Front Range communities. Less commonly it occurs as a forest pest in Colorado.
  • Numerous natural enemies attack Douglas-fir tussock moth and these will often control outbreaks after a season or two.
  • Several insecticides can be used to control Douglas-fir tussock moth during outbreaks.

©Colorado State University Extension. 3/95. Revised 2/09.


*The original version of this publication was produced by R.E. Stevens of the Rocky Mountain Forest and Range Experiment Station, D.A. Leatherman, entomologist with Colorado State Forest Service and J.W. Brewer with the former department of zoology and entomology of Colorado State University. 3/95. Revised by W. Cranshaw, entomologist, Extension, Colorado State University, I. Aguayo and D. Leatherman, current and former entomologists, Colorado State Forest Service. 2/2009

the more tender needles are eaten. During feeding, particularly when disturbed, larvae may drop from branch to branch on long silken strands. By mid-July or August, the larvae become full grown and many may migrate away from the infested tree. They pupate in brownish spindle-shaped cocoons in the vicinity of the infested trees.

In forests another defoliating insect, the western spruce budworm, favors the same hosts as Douglas-fir tussock moth and often occurs coincidently with it. As these two develop on slightly different schedules – tussock moth egg hatch usually lags behind the initiation of budworm larval feeding in the spring by as much as three weeks – care should be taken to properly identify the two and determine which is the more damaging. This becomes particularly important if controlling actions are taken. Applying insecticides for one species at the ideal timing of the other may result in effective treatments for both.

The adults emerge from late July through mid-August. The males are winged and are strong fliers, but the females have only minute, non-functional wings. Mating occurs in the immediate vicinity of the female pupal case and they then lay their characteristic mass of eggs covered with grayish hairs. There is one generation produced per year.

Management in Landscape Plantings

Outbreaks of Douglas-fir tussock moth are cyclical due to effects of several natural controls. At least seven species of parasitic wasps and a tachinid fly have been identified as parasites that are locally present. Caterpillars may be killed by general predators, notably spiders. A nuclear polyhedrosis virus disease, known as the “wilt disease”, also can be an important mortality agent during outbreaks. Bird predation on tussock moth caterpillars is considerable during the early larval stages but the longer, dense hairs on larger caterpillars makes predation by most bird species difficult. In addition, severe weather, particularly following egg hatch, can be important in limiting Douglas-fir tussock moth populations. The cumulative effects of these natural controls rarely allow Douglas-fir outbreaks to persist more than a couple of years before reverting to a normal non-damaging population level.

Surveying the site for the presence of egg masses in winter and early spring provides an outbreak potential estimate. When egg masses are easily found in the vicinity of known host trees, a higher risk exists for subsequent injury. However, trees should be monitored shortly after bud break to confirm the presence of a potentially damaging population.

Chemical controls can be effective but need to be applied thoroughly to the top of the tree. In addition, younger larvae are much more effectively controlled than older larvae, so treatment timing is best shortly after eggs have hatched. In landscape plantings, pyrethroids such as permethrin (Astro), cyfluthrin (Tempo), bifenthrin (Talstar, Onyx) and lambda-cyhalothrin (Scimitar) are effective against Douglas-fir tussock moth caterpillars. Carbaryl (Sevin, Sevimol), teburenozide (Confirm, Mimic) and spinosad (Conserve) are alternative treatments that can provide good control.

In forest settings considerations surrounding treatments and insecticide

Figure 1: Adult males of the Douglas-fir tussock moth.

Figure 2: Tussock moth egg mass at egg hatch.

Figure 5: Top-down defoliation pattern typical of Douglas-fir tussock moth.

Figure 3: Douglas-fir tussock moth larvae.

Figure 6: Douglas-fir tussock moth larvae with a disease, nucleo-polihydrosis virus.

Figure 4: Douglas-fir tussock moth larval damage.

options differ. Applications are typically made by air so large areas are simultaneously sprayed with insecticide. As a result, the potential for contamination of fish-bearing surface waters exists. Also, the presence of endangered species, such as the Pawnee Skipper, becomes particularly important to decision making. Where Douglas-fir tussock moth outbreaks are sufficiently threatening to warrant treatment, insecticide options include the microbial insecticide Bacillus thuringiensis (Foray, Dipel) and the insect growth regulators diflubenzuron (Dimilin) or tebufenozide (Confirm, Mimic).

This fact sheet was produced in cooperation with the Colorado State Forest Service.

Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

How to Identify a Hobo Spider

Printable version of How to Identify a Hobo Spider (PDF)

How to identify (or misidentify) the hobo spider

Rick Vetter 1 and Art Antonelli 2 PLS 116 Page 1

Since the late 1980s, many people in Washington have been concerned about the hobo spider because it has been blamed as the cause of dermatologic wounds. We offer here a guide to help identify some medium-sized Washington spiders found in homes. However, keep in mind that without a microscope you may not be able to identify hobo spiders and may have to settle for determining that your spider is NOT a hobo spider. This may be frustrating and not the goal you had in mind, however, quite often the question is not "What spider do I have?" but "Do I have a hobo spider?" You should be able to learn enough to eliminate many spiders from consideration without a microscope and sometimes with just the naked eye. Most people want a world with simple black/white answers but you must realize that there many shades of gray in between and this is the reality of spider identification.

This publication was initiated because there is no currently available guide to spider identification for the person with limited arachnological skills. Most of the previous guides for hobo spider identification try to give a simplistic way to discern hobo spiders. We have found that many well-intentioned people misconstrue the information and confidently misidentify their non-hobo spider as a hobo. The other references actually are reliable if you already know something about spider identification similar to the fact that a dictionary is a book that helps you spell words if you already know how to spell words. However, the misidentification of harmless spiders as hobo spiders can result in inappropriate anxiety and/or the unnecessary spraying of insecticides to kill off spider populations which are actually beneficial species

because of the insects they eat. What this publication tries to do is

1 Dept. Entomology, Univ. Calif. Riverside, CA 92521

2 Extension Specialist, Wash. St. Univ., Puyallup, WA 98371

show you that the answers are not easy to obtain but if you are interested in taking your discriminatory skills up a notch, with a little practice, you should be able to confidently determine the characteristics of spiders that are NOT hobo spiders, which will be the majority of the medium-sized spiders you will encounter.

Fig. 1 Hobo spider

Photo by P. K. Visscher © PLS 116 Page 2

A general warning

Most non-arachnologists try to use coloration as a diagnostic identifying feature. This is one of the least reliable characteristics for identification of hobo spiders because of the great variation amongst specimens within a species and because similar species sometimes overlap in their appearance with hobos. If you try to identify them by size, you will also be mistaken because the variation is tremendous. Many other species look the same to the non-arachnologist who lumps them all together as hobo spiders and often is wrong. If you continue to try to determine spiders with coloration or size, then this publication is not going to help you. You must be willing to take your skills above the level of the non-arachnologist, learn a few anatomical structures and then you will have better success. As an analogy from the world of ornithology, it is easy to determine an eagle from an owl, etc. but it takes much more skill and effort to differentiate amongst the many species of similar-looking warblers. Thus, it is the same for the hobo spider and many of the medium-sized Washington spiders. You will need to be more discriminating when dealing with hobo spiders because identification is not easy. This guide is geared toward the interested reader who has a magnifying lens or hand lens, similar to what Master Gardeners or entomologists would use. Yet even with a lens, quite often you may be able to determine that your spider is NOT a hobo spider and nothing more.

For the few who have access to microscopes we present information on how to definitively identify hobo spiders to species. For the advanced beginner, this can only be reliably achieved by comparing the male and female reproductive structures to the pictures presented here. If you are able to do this, you can learn the skills of an amateur arachnologist and can determine without a doubt whether or not you are in possession of a hobo spider.

We present mostly identification information here. If you wish to learn the biology or other aspects, you should check out the references at the end of the article.

A little bit about the spiders

The hobo spider is found throughout Washington and makes a funnel web which is a trampoline-like flat sheet leading back into a hole between bricks, under wood or in shrubs. However, there are many closely related species of spiders which also make similar webs so just because you see funnel webs on your property, does not mean that there are hobo spiders in those webs.

The scientific name of the hobo spider is Tegenariaagrestis. Also living in Washington are 2 other closely related spiders, the giant house spider, Tegenariaduellica (known as Tegenaria gigantea to some) and the barn funnel weaving spider, Tegenariadomestica (also known as the domestic house spider to some). All three of these spiders originated in Europe. Related spiders (Agelenopsispotteri, Agelenopsispennsylvanica and Hololenanedra ) are often misidentified as hobo spiders. All of these are common Washington spiders which are brown, make funnel webs and belong to the family Agelenidae. PLS 116 Page 


You will need to know some important diagnostic anatomical features (Figs. 2, 3) in order to be more discriminating with spider identification.

Cephalothorax - the first main body part to which the legs are attached

Abdomen - the second main body part

Palp - the male reproductive structure. This is a swelling or knob on the end of the "feelers" in front of the body. Some people have described it as looking like a pair of boxing gloves.

Sternum - on the underside of the cephalothorax. A flat, shield-like surface surrounded by the legs

Epigynum - the female reproductive structure, a hardened, darkened structure on the underside of the abdomen closer to the cephalothorax than the middle of the abdomen. Immatures and male spiders have nothing in this area.

Fig. 2 male black widow spider

Photo by D. Boe ©

Fig. 3 left - giant house spider

right - hobo spider

Photo by R. Vetter ©

If you have a hand lens…. - what is NOT a hobo spider

If the only magnifying device you have is a hand lens, you may have to be satisfied with knowing what is not a hobo spider. Try this out and very soon, you will be able to hone your skills and possibly move up to the next level of identification such that hobo spiders will be very easy to identify. PLS 116 Page 4

1- Spots on the sternum? Not a hobo

If your spider has 3 or 4 pairs of light spots on the lateral portions of the sternum (Fig. 4), THEN IT IS NOT A HOBO SPIDER. These spiders are the other two Tegenaria species, the giant house and the barn funnel weaving spiders. Hobo spiders have a light stripe running down the middle of the sternum. So the rule here is, "If you see spots, then a hobo it's not". However, be aware that in some specimens of the giant house and barn funnel weaving spiders, the spots are very, very faint and hence look very similar to a hobo spider

Fig. 4 left - giant house spider right - hobo spider

Photo by R. Vetter

This is why we emphasize that you can't use coloration alone to accurately identify a hobo spider.

The giant house spider is more common than the hobo spider in the Pacific area west of the Cascade Mountains. These spiders are usually much larger than hobo spiders (and people assume bigger spiders are more dangerous). In western Washington cities, they typically outnumber hobo spiders about 3 to 1 so therefore, you are much more likely to encounter a giant house spider than a hobo spider. There are no populations of giant house spiders east of the Cascades in Washington so a spider with a spotted sternum is probably the smaller barn funnel weaving spider.

2- Distinct stripes on the cephalothorax? Not a hobo

If your spider has two very distinct longitudinal dark stripes on the top side of the cephalothorax (Fig. 5), THEN IT IS NOT A HOBO SPIDER. Hobo spiders have indistinct or diffuse patterns. Washington spiders with distinct dark stripes are either Agelenopsis or Hololena spiders and possibly some wolf spiders. Unfortunately, these spiders do not have common names

Fig. 5 Hololenaspecies spider

Photo by D. Boe ©

3- Dark rings around the legs? Not a hobo

If you can see dark rings around the legs of your spider (Fig. 5), THEN IT IS NOT A HOBO SPIDER. Hobo spiders have uniformly colored legs. The most PLS 116 Page 5

common spiders that have rings around their legs are the barn funnel weaving spider and some of the other agelenid spiders like Hololena.

4- Legs and cephalothorax are shiny and dark-orange in color? Not a hobo.

If your spider has legs that are shiny and lacking fine hairs, THEN IT IS NOT A HOBO SPIDER. If the cephalothorax is also shiny and dark-orange to a mahogany in color, this is probably a Callobius spider (Fig. 6). There are many species of Callobius spiders in Washington however, Callobiusseverus is one of the most common and most widespread in Washington's most heavily populated areas. This spider is very often submitted as a potential hobo spider because of the pattern on the abdomen. Also in the side view, the palp of Callobius males has large, conspicuous, pointed projections (Fig. 7). Hobo spiders have one very small flat-top projection (see Fig. 9). The palp of the male Callobius spider is not the one from the Pacific Northwest but it will look similar enough to it such that you will be able to recognize it.

Fig. 6 Callobiusspider Fig. 7 Male Callobiuspalp projections

Photo by David Phillips © (top of palp is cut off in the picture)

www.riverfriends.com Photo by R. Vetter ©

5- The palp of the male is long and pointy? Not a hobo.

If the extreme fleshy tip of the male palp is long, thin and finger-like, THEN IT IS NOT A HOBO SPIDER. If you look at Figures 8 & 9, two of the three male palps of the closely-related Tegenaria species have long, pointed, finger-like tips. The tip of the hobo spider is more blunt.

So how do you tell for sure that you have a hobo spider?

Unfortunately, the answer is that unless you are able to examine the very small reproductive structures, you are cannot definitively identify a hobo spider. But if you have progressed this far in your arachnological skills, you will realize that you PLS 116 Page 6

have eliminated many spiders from consideration as hobo spiders which may be sufficient for your needs.

The only sure way to identify a spider as a hobo spider is to compare its reproductive structures that define it as a species. You will probably need a microscope to examine these structures.


1- FORCEPS: You should have two pairs of forceps for manipulating spiders, moving legs out of the way, etc. The finer the tips the better. BioQuip in southern California has everything entomological. They have inexpensive fine forceps for about $2.50 but if you wish to get the professional models, watchmaker's forceps are the best. They cost about $15 a pair and are also available from BioQuip and probably from various other sources like electronics stores, medical supply places, etc.

2- ILLUMINATION - you should have a strong illumination source, preferably from the side that will give better contrast of the features. Straight-on lighting will make the subject look flat. Example, photographs of hills and mountains show much more detail of the topography at dawn and dusk because they accentuate the differences in contours. The same goes for microscopic spider work. If you don't have a scientific illuminator, a high-intensity flashlight should be sufficient. If you are having trouble seeing some of the structures, move the illumination source around. This will give you different perspectives of the contours of the features.

3- SUBMERGE THE SPIDER IN ALCOHOL: to properly identify spiders, the spider needs to be completely submerged in alcohol. The reason for this is that the hairs of the body will cloak important features or distort the light. If the spider is completely submerged in alcohol, you will be looking at fewer reflections off the body parts.

4- ALCOHOL: If you are at a scientific institution, you should have no trouble getting ethanol which should be diluted to 70% with water. The general public can obtain denatured alcohol (purposely contaminated with compounds like acetone (i.e., nail polish remover) so that it is not potable). Rubbing alcohol (isopropyl alcohol) is 70% right off the drugstore shelf but causes specimens to become brittle and there are some health risks for humans more so than ethanol.

5- OBSERVING SPIDERS ALIVE: if you don't want to kill the spider, you can place the spider in a clear plastic bag and then gently flatten the bag against a contrasting surface. The spider will then be immobilized with its legs out flat and with practice, you should be able to see many of the features mentioned here. After that, you can just release the spider to the garden so it can eat more insects.

PLS 116 Page 7

Male palps

The best way to examine the male reproductive structures is to remove them from the spider because the legs often get in the way, the palp usually curls downward making it otherwise difficult to identify. Once you remove the palp, place it such that you can see all the surface structures. By convention, arachnologists always remove the left palp from a mature male spider. (Be aware that the palps of immature male spiders are merely swollen bulbs with no structures on it. They have one more molt to maturity. If this is what you have, species identification is virtually impossible and you might as well throw it away.)

In this publication, we will only address the different palps of the three Tegenaria species because by the time you have gotten this far, you should have eliminated the other spiders as non-hobos. Actually by this time you should have been able to eliminate most of the normal-looking giant house and barn funnel weaving spiders too. Again, because of variation in color and size, several specimens have fooled experts until the reproductive structures were examined.

Fig. 8 Left male palps showing differences in the surface features

Left - hobo spider, center - giant house spider, right - barn funnel weaving spider

Photo by R. Vetter ©

With the left male palp lying "on its back", you should see a variety of complex structures. Although this may appear difficult, as you look more closely, you will see darkened prominences arising from the palp. In the hobo spider, there is a hardened structure that wraps around on the outside of the palp, curves toward the middle and has two little prongs on the end. In the giant house spider, there is a thick prong, which points downward away from the palp. In the barn funnel PLS 116 Page 8

weaving spider, there is a short prong near the top which just pokes toward the outside. If you can identify the palp to any of the pictures here, then you have performed the task of a qualified arachnologist and have definitively identified the spider to species.

Fig. 9 Side view of left male palps showing differences in the RTAs

left - hobo spider, center - giant house spider, right - barn funnel weaving spider

Photo by R. Vetter ©

In a side view, there is a structure on the tibia called the retrolateral tibial apophysis (RTA). In the hobo spider, the RTA (Fig. 9) is a single projection that is squared off on top. In the giant house spider, the RTA has two projections, each on the end of a saddle. In the barn funnel weaving spider, there is a single projection that is pointed on top. We realize that the structures on the male palp may be difficult to discern here despite slight digital-enhancement. However, after comparing these pictures to actual palps under a microscope, you should readily become more proficient at determine hobo spiders. These images should give you an idea of some characters such that you can eliminate some spiders from consideration.

Also in the figure above, for the giant house spider you can see the longer fingerlike, upward extension and also the downward projecting prong on the surface of the palp. The size differences between spiders can also be detected.PLS 116 Page 9

Female Epigynum

The epigynum of the female is the opening to her reproductive organs and is usually a hardened plate. It is located on the underside of the abdomen. This is going to be more difficult than the male and you will surely need a microscope for this whereas with the male palp, sometimes a very good hand lens will suffice. In immature females, there is nothing near the location where the epigynum will eventually form and you might as well throw away the specimen.

In the hobo spider, the epigynum contains a large atrium (cavity), in the middle, which is surrounded by thick, raised ridges (in Fig. 10, two slanted white side ridges and one below). If you can see an epigynum similar to the figure to the right, then you have a hobo spider because nothing else looks like this. Be aware that other spider species have an atrium but it looks very different.

Female giant house spiders (Fig. 11) have no atrium (the middle portion is a shiny, flat surface) and have large pointed spurs near the bottom of the epigynum that point toward each other. You may need to remove the hairs from this area with a needle to see the spurs.

The barn funnel weaving spider (Fig. 12) is sometimes very difficult to identify because the variation in the epigynum sometimes leaves a very subtle structure. However, the barn funnel weaving spider female epigynum does not have an atrium and looks something like a bracket with a blurry spot on either end.

Fig. 10 hobo spider epigynum

Photo by R. Vetter ©

Fig. 11 giant house spider epigynum

Photo by R. Vetter ©

Fig. 12 barn funnel weaving spider epigynum

Photo by R. Vetter © PLS 116 Page 10

References providing biology and distribution information:

Akre, R. D., and E. A. Myhre. 1991. Biology and medical importance of the aggressive house spider, Tegenariaagrestis, in the Pacific Northwest (Arachnida: Araneae: Agelenidae). Melanderia 47: 1-30.

Baird, C. R., and R. D. Akre. 1993. Range extension of the aggressive house spider Tegenariaagrestis into southern Idaho, Utah and Montana. Proc. Wash. St. Entomol. Soc. 55: 996-1000.

Crawford, R., and D. K. Vest. 1989. The hobo spider and other European house spiders. Burke Mus. Educ. Bull. #1, 4pp.

Vetter, R. S. 2001. Hobo spider. Univ. Calif. Pest Notes #7488, 3 pp. 

Vetter, R. S., A. H. Roe, R. G. Bennett, C. R. Baird, L. A. Royce, W. T. Lanier, A. L. Antonelli and P.E. Cushing. (submitted). Distribution of the medically-implicated hobo spider (Araneae: Agelenidae) and its harmless congener, Tegenariaduellica in the United States and Canada. (J. med. Entomol. - in press.)

Managing Mountain Pine Beetle

Printable version of Managing Mountain Pine Beetle (PDF)

Managing Mountain Pine Beetle (MPB) Attacking Urban And Shelterbelt Trees In Montana

1) Learn to recognize the signs and symptoms of MPB attack. Evaluate the degree of risk to pine trees on your

property. Is the property close to an infested forest? Are there infested trees on your property or in the general


2) Practice prevention. Remove and destroy infested trees by June 1 before beetles emerge to attack nearby

trees. Do not bring infested firewood onto your property. If the pine trees are at risk of attack keep them well


3) If your pine trees are at risk, consider protecting them. Trees can be protected by spraying the trunks with an

insecticide or by applying a repellent pheromone prior to July 1.

4) During the fall season evaluate MPB damage to your pine trees and develop a management plan that utilizes

prevention and protection if necessary. The current infestation in Montana will likely last for at least another 3

to 5 more years.

Signs And Symptoms Of Mountain Pine Beetle Attack

In Montana beetles typically fly during July and August when they attack pine trees. All species of pine can be

attacked, but native lodgepole and ponderosa pine, and introduced ornamental Scots pine are preferred hosts.

Hundreds of the tiny beetles bore through the tree bark and lay eggs within the inner bark. The white grub-like

larvae feed on the inside of the bark. Pitch tubes produced at beetle entry points, and boring dust that

accumulates at the base of the tree, are some of the first signs of attack that become visible in August and


Figure 2 above: Scots pine tree mass attacked by thousands of beetles. At each entry point the tree exudes sap

and pitch in an attempt to repel the beetle, producing distinctive “pitch tubes”. Each pitch tube represents a

point of entry where a single beetle chewed trough the bark.

Figure 3 above: Trees may not always produce pitch tubes, particularly drought stressed trees that have less

sap. Boring dust at the base of the tree is another sign of infestation. As the adult beetles chew and construct

galleries underneath the bark they push out the dust. With hundreds of beetles at work, boring dust accumulates

at the base of the tree, looking something like sawdust. Boring dust is a sign of an active infestation.

Figure 4 above: Left, after boring through the bark, female beetles construct a vertical gallery underneath the

bark. When a tree is attacked by hundreds of beetles, the inner bark is destroyed by their feeding activity

(middle picture). After mating, female beetles lay eggs along the vertical gallery. The eggs hatch into small

grub-like larvae (upper right) that feed in a horizontal direction. The smaller larval feeding galleries radiating

out from the larger vertical gallery produced by the adults produces a characteristic pattern underneath the bark

(lower right hand corner).

Figure 5 above.

As mountain pine beetles bore into a tree, they bring with them blue stain fungi that colonize the tree. The blue

stain commonly seen on pinewood lumber or furniture is caused by blue stain fungi. The fungi invade the inner

bark as well as the sapwood of the tree trunk The picture above left is a cross section of pine tree with blue stain

fungi growing towards the center. It is the combined action of the beetle feeding and the stain fungi that girdles

and kills the tree. Although mass attacked trees will stay green over the winter (center picture) much like a

Christmas tree, the damage has been done. The tree is girdled, and when temperatures rise in the spring, mass

attacked trees will begin to turn yellow and die from lack of water and nutrients (right-side picture). Despite the

snow on the ground, the picture above right was taken during April 2009.

Will My Urban Pine Tree Die?

In some cases pine trees can successfully repel beetle attacks, particularly if the tree was attacked by a smaller

number of beetles, such as a “strip attack”. A strip attack occurs when only one side of the tree is attacked. In a

forest setting, sacrificing a few trees for the benefit of the forest is acceptable. However, in an urban setting,

homeowners and landowners do not want to cut down high value trees unless they are sure that they will die.

Because some trees may remain green well into the spring before they die, it is not as simple as waiting for

them to turn red. Predicting the fate of “strip attacked” trees is variable and difficult. First, the trees health can

be monitored into the spring season. If attacked trees turns yellow during April and May they will not survive.

Second. small 1” square pieces of bark can be cut from the trunk of attacked trees on the North, East, South and

West sides. If the inner bark on three or more squares is damaged, the tree will most likely NOT survive. If two

or more squares have healthy bark, tree has a CHANCE of surviving. These trees may benefit from extra

watering in the spring. Healthy bark is white and moist, damaged bark is brown and “chewed up”, see Figure 4

above. However, if infested trees are not removed and destroyed by July 1, they present a risk to neighboring

healthy pine trees (see prevention section below).

Is My Spruce Tree At Risk?

Pine trees are the preferred host of the mountain pine beetle and spruce are at low risk. Occasionally other

conifer species such as spruce and fir can be attacked. In a forest this typically occurs when beetle populations

are high and there are no other hosts available (all of the pine trees have been killed during the infestation). In

urban environments spruce trees right beside a mass attacked pine tree have been attacked. These cases are

likely “spill over” attacks, when too many beetles are attracted to the primary host and the beetles go to the next

closest conifer. In the city of Great Falls approximately 1000 attacked trees were identified and only about 6-8

were spruce trees less than 1% of the attacked trees were spruce. Overall the risk is low, but occasionally it

can occur. Also be aware that different species of bark beetles can attack spruce and fir, such as the spruce and

Douglas fir beetles.

Figure 6: Adult mountain pine beetles under the bark of a Scots pine tree. These are tiny beetles not much

larger than a grain of rice.


If your trees are at risk of attack, consider preventative measures. Well watered trees are able to produce more

sap and may “pitch out” and repel the beetles, and are generally more able to recover from attacks. If you have

infested trees on your property consider removing and destroying them prior to June 1. During July and August

a new generation of beetles emerges from infested trees to look for new hosts to attack. Healthy pine trees that

are close to infested trees are at much higher risk of attack. When infested trees are removed, the beetles

underneath the bark must be destroyed by chipping, burning or burying the wood. Simply cutting and splitting

the wood does not kill the beetles underneath the bark. Contact your local county agent or city forester to learn

if your area has a designated disposal site.

Figure 7: Mountain pine beetle life cycle.

Scientific Name: Dendroctonusponderosae.

Hosts: Primarily lodgepole and ponderosa pines,

but any pine species can be attacked. Introduced

ornamental Scots pine is highly attractive to the


Most of its life cycle is spent underneath the tree

bark where it typically takes one year to develop

through egg, larva, pupa and adult stages.

Adult beetles fly during July and August attacking

pine trees. Eggs hatch and larvae feed during the

fall season. Immature larvae spend the winter

underneath the bark. The following spring season

larvae resume feeding and develop into pupae on

the way to becoming the next generation of adult

beetles that emerge during July and August.


Care should be taken when firewood is cut and transported. The beetles can continue to develop under the bark

of infested firewood and emerge to attack nearby pine trees. Standing dead pine trees that are completely greybrown

typically do not have living bark beetles. Trees attacked during the fall season harbor beetles until the

end of August of the following year. Pine trees that are red during July and August may contain beetles. Trees

cut for firewood can be inspected by removing some bark with an axe. Sign of old abandoned galleries is fine

as long as there are no adult or larval beetles present (Figures 1 and 4).


Prevention is helpful but alone it may not be enough. High value urban pine trees can be protected from attack

using a repellent pheromone (verbenone) or by spraying the tree trunks with an insecticide.


Mountain pine beetles produce attractive and repellent pheromone chemicals when attacking pine trees. The

first beetles to attack produce an aggregation pheromone that attracts other beetles in the area to “mass attack”

and overcome the host tree’s defenses. When the tree is full the beetles begin producing an anti-aggregation

pheromone that prevents too many beetles from attacking the same tree. The anti-aggregation pheromone,

called verbenone, is sold commercially. Verbenone is sold as a liquid pouch that is attached to the tree trunk, as

the verbenone evaporates beetles in the area can smell it and they are repelled.

Two verbenone pouches should be attached to each high value pine tree, on the north facing side of the tree

trunk about six feet high. The pouches should not be placed on top of each other, they should be spaced a few

inches apart, one on the northeast side and one on the northwest side. The north side of the tree is cooler and

prevents rapid evaporation of the pheromone. Commercial packaging may provide instructions for different

regions in North America. In Montana MPB typically flies during July and August.

For best effectiveness verbenone pouches should be applied at the end of June, before July 1.

Figure 8: The repellent pheromone verbenone is sold as liquid pouches

that are attached to the tree trunk. In forests vebenone is spaced and

applied in a grid pattern. In urban settings, high value pine trees are

protected by applying two pouches per tree at the end of June, before the

first of July.

USDA Forest service research has found that two pouches of verbenone applied to each pine tree at the end of

June protected 80% or more of the trees that were treated (see “verbenone report” link). Please note that these

recommendations are for protecting small numbers of high value trees. Recommendations for deploying

verbenone in forest and woodlot settings are based on numbers of pouches per acre of forest,

Verbenone is now sold at retail stores in


Verbenone is available at retail stores in Montana or directly through two companies in Vancouver British


Phero Tech, Inc. Synergy Semiochemical Corp.

7572 Progress Way Box 50008, South Slope RPO

Delta, B. C. Canada V4G 1E9 Burnaby, B. C. Canada V5J 5G3

Phone: 604-940-9944 Phone: 604-454-1121


Verbenone is non toxic and only affects the mountain pine beetle. It is easy to apply. However, it is not as

effective as insecticides sprayed onto the tree trunk. Tree trunks need to be covered thoroughly on all sides,

from ground level up to a stem diameter of about 4-5 inches. Trees can be treated from April through to the end

of June. Several insecticides are available for controlling MPB: SevinXLR (agricultural/forest use), SevinSL

(urban use), Astro and Onyx. All are 95-100% effective in protecting pine trees from MPB attack during the

same year of application. Sevin can provide two years of protection, the year of application and the following

year. Protection during the second year may be more variable, but applying Sevin once every two years may be

more cost effective particularly for larger numbers of trees.

Trees must be sprayed protectively, before the beetles fly and attack. Spraying trees after they have been

attacked will not save them. Beetles come into contact with and ingest the insecticide when boring through the

bark. Previous studies have found that systemic insecticides are not effective against bark beetles. Registered

pesticide applicators are recommended; when using an insecticide carefully follow the label instructions.


Is some sort of action necessary? This is not an easy question, it relates to the degree of risk and the potential

consequence. In urban environments it is difficult to predict where the beetles may turn up. However, after the

beetles have mass attacked a tree, the damage has been done and there are no reliable treatments to save it. The

decision is really a balance between the risk that your trees will be attacked and killed and the cost of taking

action to protect them without ever knowing whether they will be attacked.

Risk: How did the beetles find their way from forests to isolated shelter belts in 2008? Beetles can fly

considerable distances, but they may also be aided by prevailing winds. Future occurrences in urban

environments are difficult to predict. We do know that the mountain pine beetle infestation will continue for

several more years in the surrounding pine forests. If your or your neighbor’s trees were attacked in 2008, it is

reasonable to think that the trees are at risk again during the summer of 2009. Mountain pine beetles live in

forests, the closer your location is to an infested forest, particularly if it is downwind, the greater the risk.

Montana Bee Identification Guide

Printable version of Montana Bee Identification Guide (PDF)

Montana Bee Identification Guide

  • Solitary; nest in natural or man-made holes such as beetle tunnels or wood nesting blocks.
  • Females cut circular pieces from leaves and use them to line their nests.

Casey M. Delphia1, Kevin M. O’Neill1, and Scott Prajzner2

1Department of Land Resources & Environmental Sciences, Montana State University, Bozeman, MT

2Department of Entomology, Ohio State University OARDC, Wooster, OH

In cooperation with Pollinator Partnership

Bee Identification

Bees, like other insects, have three body segments: a head, thorax, and abdomen. The headconsists of the compound eyes, antennae that are segmented and bent, and mouthparts that include jaws for chewing and a tongue for drinking nectar. The thoraxbears the legs and four wings (two forewings and two hind-wings). The abdomencontains the sting in female bees. Female bees also have special pollen-carrying hairsor other structures commonly found on the hind legs or the underside of the abdomen. For example, honey bees carry pollen in a pollen basket which is an area on the hind leg that is bare and surrounded by incurving hairs.

Honey bee (Apis mellifera)

Bumble bees (Bombusspp.)

Family: Apidae. Heart-shaped head; hairy eyes; black to amber-brown body with pale and dark stripes on abdomen; barrel-shaped abdomen; pollen basket on hind legs; 10-15mm.

Family: Apidae. Robust, hairy bees; black body covered with black, yellow, orange, or white hairs in bands; pollen basket on hind legs; 10-23 mm.

©2010 Lynette Schimming

  • Social colonies; live in man-made hives and natural cavities like tree holes; swarm to locate new nests.
  • Honey bees are managed for crop pollination and honey production.

Leafcutting bees (Megachilespp.)

Family: Megachilidae. Head as broad as thorax; large jaws used to cut leaves; black body with pale hair bands on abdomen; pollen-carrying hairs on the underside of abdomen; 7-15 mm.©2008 RKD Peterson©2007 RKD Peterson

©2005 Hartmut WischSweat bees (Family: Halictidae)Many forms including: dull black/brown body with light abdominal hair bands, bright metallic green, dull metallic blue, copper, or green, and black with a red abdomen (parasites of other bees); pollen-carrying hairs on hind legs (except in parasitic bees); 3-11mm.

©2010 Lynette Schimming

© 2009 Gary McDonald

  • Solitary, communal, and semisocialsoil nesters; some are attracted to the salt in your sweat. 

© 2009 Gary McDonald

© 2010 Tom Murray

©2011 Casey M Delphia

Bees play an important role in natural and agricultural systems as pollinators of flowering plants that provide food, fiber, animal forage, and ecological services like soil and water conservation. In fact, approximately three-quarters of all flowering plants rely on pollinators to reproduce. In addition to honey bees, native bees provide valuable pollination services. Though unknown, the number of native bee species in Montana is likely in the hundreds.

This guide provides information for identifying 10 types of bees commonly found in Montana including descriptions of key characters, size (mm), nesting habitat, and other identifying behaviors.

©2011 Casey M Delphiaabdomen


headpollen-carrying hairs on abdomenpollen-carrying hairs on hind leg

  • Social colonies; often nest underground in small cavities like old rodent burrows.
  • Bumble bees can buzz-pollinate, which is important for plants that require vibration to release pollen.

©2009 Casey M Delphia

Mason bees (Osmiaspp.)

Yellow-faced or masked bees (Hylaeus spp.)

Small carpenter bees (Ceratinaspp.)Family: Apidae. Shiny, dark metallic blue-green body; sparsely haired; distinctive cylindrical abdomen; pollen-carrying hairs on hind legs; 3-10 mm.

Family: Megachilidae. Robust body; broad, round head and abdomen; usually metallic green or blue; pollen-carrying hairs on underside of abdomen; 5-20 mm.

Family: Colletidae. Slender; almost hairless; black body with yellow or white markings on head, thorax and legs; no pollen-carrying hairs; 5-7 mm.

A Bee or Not a Bee?

There are two major groups of insects that are commonly confused with bees—flies and wasps. In fact, many flower-visiting flies are actuallybee mimics. By mimicking bees in appearance, they are able to gain protection from predators and even act as bee parasites. So how do you tell them all apart?

Fly Identification: Flies have only two wings, while bees have four. Flies have short, stubby antennae with long hairs or feathery antennae and sucking or sponging mouthparts. Many flies have large eyes that almost meet at the top of their heads.

Wasp Identification: Similar to bees, waspshave four wings, chewing mouthparts, a sting, and long antennae. But, while bees are usually very hairy, wasps are usually smooth and almost hairless. Wasps also have a typical, slender “wasp waist” and rarely have pollen-carrying hairs because most are carnivores and don’t eat pollen. Wasps are important predators of many pest insects including cutworms, aphids, and grasshoppers. Additionally, some wasps make paper nests in trees or on buildings.

Now that you know how to tell the difference between bees, wasps, and flies, try identifying these insects. Answers are at the bottom.

© 2010 Tom Murray

©2010 Lynette Schimming© 2008 Gary McDonald

Answers: 1) Wasp 2) Fly 3) Fly 4) Wasp 5) Sweat bee

6) Cuckoo Bee 7) Leaf cutting bee 8) Wasp 9) Fly

©2010 Ken Kertell©2009 Steve NanzLong horned bees (Melissodesspp.)Family: Apidae. Robust; hairy; black body with pale hair bands on abdomen; dense pollen-carrying hairs on hind legs; males have very long antennae; 7-16 mm.© 2009 Kevin Hall© 2009 J.C. Lucier

©2006 Tom Murray

Mining bees (Andrenaspp.)Family: Andrenidae. Black or dull metallic blue or green body; fairly hairy; pollen-carrying hairs on upper parts of hind legs (resemble “armpits”); 6-15 mm.

© 2010 Ted Kropiewnicki

Cuckoo bees (Nomadaspp.)

Family: Apidae. Wasp-like; sparse branched hairs; red or black body with yellow or white markings; relatively thick antennae; no pollen-carrying hairs; 5-15 mm.

©2010 Tom Murray

©2008 Hartmut Wisch©2007 Lynette Schimming

©2004 RKD Peterson

©2008 RKD Peterson©2008 RKD Peterson©2005 RKD Peterson©2004 RKD Peterson©2009 Lynette Schimming©2006 Lynette Schimming

©2008 Lynette Schimming








Acknowledgements: Thank you to GennaBoland for assistance with AutoMontage® photographs and image editing.

  • Solitary; nest in dead twigs and stems.
  • Yellow or white markings on face (females have avertical bar, males have an inverted T).
  • Solitary; nest in the ground; prefer sandy soil.
  • Andrenids are very abundant in the spring as they are one of the first bees to emerge each season.
  • Solitary; nest in natural or man-made holes like beetle tunnels, wood nesting blocks, or reed stems.
  • Use mud or chewed-up leaves/petals for nest walls.
  • Solitary to communal ground nesters.
  • Some are especially attracted to asters, sunflowers, and daisies.
  • Solitary; nest in twigs, stems, and existing tunnels in wood.
  • Carry pollen and nectar in a special storage structure of the digestive system called a crop.
  • Females visit flowers for nectar, but do not collect pollen for their young.
  • Females are cleptoparasites-they lay eggs in nests of other bees thereby stealing the nests and food.

©2010 Tom Murray

MSU IPM Biologial Controls

Printable version of MSU IPM Biological Controls (PDF)


Products listed alphabetically: Product

Biocontrol Agent

Target Pathogen




Application Method





Tobacco, tomato, lettuce, spinach

Water dispersible granule.


Syngenta Crop Protection P.O. Box 18300, Greensboro, NC 27419 USA. Phone: 1-800-334-9481 www.syngentacropprotection-us.com/


Streptomyces lydicus

soilborne disease

greenhouse and nursery crops, turf

water-dispersible granule


Manufacturer/Distributor: Natural Industries, Inc. 6223 Theall Rd., Houston, TX 77066 USA. Phone: 888-261-4731, FAX: 281-580-4163. www.naturalindustries.com/index.html


Aspergillus flavus AF36

Aspergillus flavus strains that pruduce aflatoxin


sterilized wheat seeds colonized by A. flavus

aerial or ground equipment

Arizona Cotton Research and Protection Council, 3721 East Wier Ave., Phoenix, AZ 85040 USA


Aspergillus flavus NRRL 21882

Strains of the fungus A. flavus that produces aflatoxin


granules containing 0.01% A. flavus NRRL 21882

applied to soil at 1 gram ai/acre once per year, 40-80 days after the peanuts are planted

Circle One Global, Inc. One Arthur Street, PO Box 28, Shellman, GA 39886-0028. Phone: 229-768-2538

All Natural 3-in-1 Garden Insect Spray

Rosemary oil, clove oil, cottonseed oil

Powdery mildew, rusts, leaf spots, bacterial spot and speck, anthracnose, fire blight, greasy spot, scab, brown rot, leaf curl, bunch rot, early late blight and many others.

Fruits, Vegetables & Ornamentals




Pseudomonas chlororaphis63-28

wilt diseases as well as stem and root rots

ornamentals and vegetables grown in greenhouses


Turf Science Laboratories, Inc., 2121 Hoover Ave., National City, CA 91950 USA.

AQ10 Biofungicide

Ampelomycesquisqualisisolate M-10

powdery mildew

apples, cucurbits, grapes, ornamentals, strawberries, and tomatoes

water-dispersible granule


Ecogen, Inc., 2005 Cabot Blvd. West, Langhorne, PA 19074; Phone: 1-215-757-1590; FAX: 1-215-752-2461


Bacillus pumilus QST2808

Asian soybean rust




AgraQuest, Inc., 1530 Drew Avenue, Davis, CA 95616 USA. Phone: 1-530-750-0150, Fax: 1-530-750-0153, www.agraquest.com

Binab T Wettable Powder Biorational Fungicide

Trichoderma harzianum ATCC 20476 and Trichoderma polysporum ATCC 20475

fungi that infect tree wounds

ornamental, shade, and forest trees


as a slurry to the wound

BINAB Bio-Innovation EFTR AB, Florettgatan 5, SE-254 67 Helsingborg, Sweden. Phone: 46-42-16-37-04, Fax: 46-42-16-24-97, www.algonet.se/~binab/index2.html

Bio-save 10LP, 110

Pseudomonas syringae

Botrytis cinerea, Penicillium spp., Mucor pyroformis, Geotrichumcandidum

pome fruit, citrus, cherries, and potatoes

lyophilized product, frozen cell concentrated pellets

pellets added to water to produce liquid suspension, postharvest application to fruit as drench, dip or spray

JET Harvest Solutions, PO Box 915139, Longwood, FL 32791 USA. Phone: 1-877-866-5773, www.jetharvest.com

BlightBan A506

Pseudomonas fluorescens A506

Frost damage, Erwinia amylovora, and russet-inducing bacteria

almond, apple, apricot, blueberry, cherry, peach, pear, potato, strawberry, tomato

wettable powder

bloom time spray of the flower and fruit

NuFarm Inc., 1-708-754-3330, www.nufarm.com


Bacillus subtilis GB03, other B. subtilis ,B. lichenformis, B. megaterium

Rhizoctonia, Pythium, Fusarium,and Phytophthora

Greenhouse and nursery


drench at time of seeding and transplanting or as a spray for turf

Growth Products, Ltd., PO Box 1252, Westmoreland Ave., White Plains, NY 10602 USA. Phone: 1-800-648-7626, Fax: 914-428-2780, Internet: www.growthproducts.com

Contans WG, Intercept WG

Coniothyriumminitans strain CON/M/91-08

Sclerotiniasclerotiorum and S. minor


water dispersible granule


Sylvan Bioproducts, Inc., 333 Main Street, PO Box 249, Saxonburg, PA 16056-0249 USA. Phone: 1-724-352-7520, www.sylvanbio.com

Concern Copper Soap

Copper with fatty acids

Downy mildew, leaf and fruit spots, blights and rusts

Flowers, fruits and vegetables indoor and outdoor



Woodstream Corporation

69 North Locust Street

Lititz, PA 17543


fermentation product of killed Myrothecium verrucaria (killed)

Parasitic nematodes

cole crops, grape, ornamentals, turf, trees

powder and liquid suspension from fermentation

to soil and incorporated by various methods

Valent Biosciences, Inc., 1333 N. California Boulevard #600, Walnut Creek, CA 94596, USA. Phone: 800-6-VALENT. www.valent.com


Bacillus licheniformis SB3086

Dollar spot, low and moderate disease pressure


liquid spore concentrate

standard spray equipment

Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark. Phone: 45-88-24-99-99, Fax: 45-88-24-99-98; or Novozymes Biologicals, Inc., 5400 Corporate Circle, Salem, VA, 24153.


Frostban A

Pseudomonas fluorescens strains A506 and 1629RS, Pseudomonas syringae742RS

frost-forming bacteria

certain fruits, almond, potato, and tomato crops

two to four spray applications early in growing season

Frost Technology Corporation, 1333 Burr Ridge Parkway, Suite 125A, Burr Ridge, IL 60527 USA.

Frostban B

Pseudomonas fluorescens A506

frost-forming bacteria

certain fruits, almond, potato, and tomato crops

two to four spray applications early in growing season

Frost Technology Corporation, 1333 Burr Ridge Parkway, Suite 125A, Burr Ridge, IL 60527 USA.

Frostban C

Pseudomonas syringae742RS

frost-forming bacteria

certain fruits, almond, potato, and tomato crops

two to four spray applications early in growing season

Frost Technology Corporation, 1333 Burr Ridge Parkway, Suite 125A, Burr Ridge, IL 60527 USA.

Frostban D

Pseudomonas fluorescens 1629RS

frost-forming bacteria

certain fruits, almond, potato, and tomato crops

two to four spray applications early in growing season

Frost Technology Corporation, 1333 Burr Ridge Parkway, Suite 125A, Burr Ridge, IL 60527 USA.


Mint oil, Citric Acid, Glycerol, Citrus Pulp (strained), Fish Oil (edible), Vitamin C (ascorbic acid) and water.

Alternaria, Aspergillus, Botrytis, Bremia, Erysiphe, Microsphaera, Pseudoperonospora, Phytophtora, Sclerotinia, Fusarium Patch, Fairy Ring, Take-all Patch

Turf and ornamentals



Soil Technologies

2103 185th St.,

Fairfield, IA 52556 USA



Agrobacterium radiobacter Strain 84

crown gall disease caused by Agrobacterium tumefaciens

fruit, nut, and ornamental nursery stock

petri plates with pure culture grown on agar

bacterial mass from one plate transferred to one gallon of non-chlorinated water; suspension applied to seeds, seedlings, cuttings, roots, stems, and as soil drench

AgBioChem, Inc., 3 Fleetwood Ct., Orinda, CA 94563, USA. Phone: 1-925-254-0789 or 10795 Byrne Avenue, Red Bluff, CA, 90860 USA. Phone: 1-530-527-8028, www.crowngall.com

GB34 Biological Fungicide

Bacillus pumilus GB34

fungal pests Rhizoctonia and Fusarium

soybean seeds

slurry applied to seeds using specified mechanical seed-treating equipment

Gustafson LLC, 1400 Preston Road, Suite 400, Plano, TX 75093, USA. Phone: 972-985-5617, Fax: 972-985-1696, www.gustafson.com


Garlic oil

Powdery mildew, rust, downy mildew

Ornamental indoor and outside



JH BIOTECH, INC. 4951 Olivas Park Drive, Ventura, CA 93003

Phone: (805) 650-8933 www.jhbiotech.com/


Potassium bicarbonate and surfactants

Powdery mildew and other fungi

Flowers, trees, houseplants, fruits, vegetables and turf



H & I Agritech, Inc.

95 Brown Road, Box 1030

Product Name Ithaca, NY 14850

Green Releaf

Bacillus licheniformis SB3086

many fungal species especially those causing leaf spot and blight diseases

ornamental turf, lawns, golf courses, ornamental plants, conifers and tree seedlings in outdoor, greenhouse, and nursery sites

diluted in water and sprayed on leaves or applied to soil

Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark. Phone: 45-88-24-99-99, Fax: 45-88-24-99-98; or Novozymes Biologicals, Inc., 111Kesler Mill Rd., Salem, VA 24153, USA; www.novozymes.com

HiStick N/T

Bacillus subtilis MBI600 (rhizobia also in formulation)

Fusarium spp., Rhizoctoniaspp, Aspergillus

soybean, alfalfa, dry/snap beans, peanuts

slurry, damp and dry inoculation of seed

Becker Underwood, 801 Dayton Ave., PO BOX 667, Ames, IA 50010. Phone: 515-232-5907, FAX: 515-232-5961, www.beckerunderwood.com

Kodiak (several formulations)

Bacillus subtilis GB03

Rhizoctoniasolani, Fusarium spp., Alternaria spp., and Aspergillus spp. that attack roots

cotton, legumes

dry powder; usually applied with chemical fungicides

added to a slurry mix for seed treatment; hopper box treatment

Gustafson, Inc., 1400 Preston Rd, Suite 400, Plano, TX 75093 USA. Phone 1-800-248-6907 or 1-972-985-8877; Fax: 1-972-985-1696, www.gustafson.com

MeloCon WG

Paecilomyceslilacinusstrain 251

Plant parasitic nematodes


water dispersible granule

spray, drench, drip irrigation

WF Stoneman Company LLC. PO Box 465, McFarland, WI 53558-0465. [email protected]


Bacillus cereus BP01

Uniform plant height, decrease in vegetative growth, larger cotton bolls

cotton plants

aerial and ground spraying

Micro-Flo Company LLC, 530 Oak Court Drive, Memphis, TN, 38117 USA. Phone: 1-800-451-8461, Fax: 901-432-5100, www.microflocompany.com


Erwinia amylovoraHrpNharpin protein.


field, ornamental, and vegetable crops


drench or spray.

EDEN Bioscience Corporation, 3830 Monte Villa Parkway, Suite 100, Bothell, WA 98021-7266 USA. Phone: 888-879-2420 or 425-806-7300, Fax: 425-806-7400, www.edenbio.com


Streptomyces griseoviridisstrain K61

Fusarium spp., Alternaria brassicola, Phomopsis spp., Botrytis spp., Pythium spp., and Phytophthora spp. that cause seed, root, and stem rot, and wilt disease

field, ornamental, and vegetable crops


drench, spray or through irrigation system

AgBio Inc., 9915 Raleigh St., Westminster, CO 80031 USA. Phone: 877-268-2020, Fax: 303-469-9598, www.agbio-inc.com


Agrobacterium radiobacterK1026

Agrobacterium tumefaciens

fruit and nut trees, caneberries, roses, and other ornamental nursery stock

pure culture in pre-sterilized, neutralized, finely divided peat

culture diluted in nonchlorinated water then used as for seed, root, or cutting dips or sprays

New BioProducts, Inc., 4272 NW Pintail Place, Corvallis, OR 97330 USA. Phone: 541-752-2045; Fax: 541-754-3968, www.newbioproducts.com



catenulatum strain J1446

soilborne pathogens that cause seed, root, and stem rot, and wilt disease

ornamental, vegetable, and tree crops


drench, spray or through irrigation system

AgBio Development Inc., 9915 Raleigh St., Westminster, CO 80031; Phone 877-268-2020, 303-469-9221; FAX 303-469-9598. www.agbio-inc.com


Trichoderma harzianumRifai strain KRL-AG2 (T-22)

Pythium spp., Rhizoctoniasolani, Fusarium spp.

trees, shrubs, transplants, all ornamentals, cabbage, tomato, cucumber

granules or wettable powder

granules mixed with soil or potting medium; powder mixed with water and added as a soil drench

Bioworks, Inc., 345 Woodcliff Dr., First Floor, Fairport, NY 14450 USA. Phone: 1-800-877-9443 or 585-641-0581, Fax: 1-800-903-2377 or 585-641-0584, www.bioworksbiocontrol.com

Serenade / Rhapsody/ Serenade Garden

Bacillus subtilis QWT713

powdery mildew, downy mildew, Cercospora leaf spot, early blight, late blight, brown rot, fire blight, and others

cucurbits, grapes, hops, vegetables, peanuts, pome fruits, stone fruits, and others

wettable powder


AgraQuest, Inc., 1530 Drew Avenue, Davis, CA 95616 USA. Phone: 1-530-750-0150, Fax: 1-530-750-0153, www.agraquest.com


Copper octanoate

Powdery mildew, downy mildew, leaf and fruit spots, rusts, fruit rots

Fruits, flowers, vegetables, ornamentals

Flowable concentrate


Gardens alive! inc 5100 Schenley place Lawrenceburg, IN 47025 Company Number: 056872


Bacillus pumilus

powdery mildew, downy mildew, Cercospora leaf spot, early blight, late blight, brown rot, fire blight, and others

cucurbits, grapes, hops, vegetables, peanuts, pome fruits, stone fruits, and others

wettable powder


AgraQuest, Inc., 1530 Drew Avenue, Davis, CA 95616 USA. Phone: 1-530-750-0150, Fax: 1-530-750-0153, www.agraquest.com


Gliocladiumvirens GL-21

damping-off and root rot pathogens especially Rhizoctoniasolani and Pythium spp.

ornamental and food crop plants grown in greenhouses, nurseries, homes, and interiorscapes


granules are incorporated in soil or soilless growing media prior to seeding

Certis USA LLC, 9145 Guilford Road, Suite 175, Columbia, MD 21046 USA. Phone: 1-301-604-7340 or 1-800-847-5620, Fax: 1 301-604-7015, www.certisusa.com

Spot-Less Biofungicide

Pseudomonas aureofaciensTx-1

dollar spot, anthracnose, Pythium, pink snow mold


added directly to sprinkler system

Turf Science Laboratories, Inc., 2121 Hoover Ave., National City, CA 91950 USA.

Stylet-oil, Sunspray Ultra-fine

Mineral oil

Powdery mildew, rust, black spot, Cercospora, Botrytis, Alternaria leaf spot, gummy stem blight, viruses (vector control)

Fruit trees, vegetables, small fruits, turf, roses



JMS Flower Farms, Inc, 4423 5th Place SW, Vero Beach, FL 32968



Bacillus subtilis MBI600

Fusarium spp., Rhizoctonia spp., and Pythium spp. that cause seed and root rots

field, ornamental, and vegetable crops


drench, spray or through irrigation system

Becker Underwood, 801 Dayton Ave., PO BOX 667, Ames, IA 50010. Phone: 515-232-5907, FAX: 515-232-5961, www.beckerunderwood.com

Taegro, Tae-Technical

Bacillus subtilis var. amyloliquefaciens FZB24

Rhizoctonia and Fusarium

Only in greenhouses and other indoor sites on shade and forest tree seedlings, ornamentals, and shrubs. Not permitted for use on food crops.


suspend in water and either drench or dip plants

Earth Biosciences Inc., 106 Somerset Ave., Fairfield, CT 06824, USA.


Sodium carbonate peroxyhydrate and other

Moss, slime molds, algae, Brown Patch, Dollar Spot, Snow Mold, Pythium , Liverwort

Lawns, Ornamental Shrubs, Flowerbeds

and Walkways. Indoor outdoor


Dry spreader

BioSafe Systems LLC

22 Meadow Street

East Hartford, CT 06108


Neem oil

Alternaria, Anthracnose,

Early blight, Leaf blight, Botrytis, Greasy spot, Leaf spot, Post bloom fruit drop, Powdery mildew, Molds, Scabs, Rusts, Shothole

vegetables, fruits, nuts, melons, outdoor ornamental plants and agronomic crops



Certis USA LLC, 9145 Guilford Road, Suite 175, Columbia, MD 21046 USA. Phone: 1-301-604-7340 or 1-800-847-5620, Fax: 1 301-604-7015, www.certisusa.com



Soilborne fungal pathogens causing root diseases


dry powder

added to a slurry mix for seed treatment; hopper box treatment.

Gustafson, Inc., 1400 Preston Rd, Plano TX 75093 USA; Phone 1-800-248-6907 or 1-972-985-8877; FAX 1-972-985-1696. www.gustafson.com


Hydrogen peroxide and other

Algae - Anthracnose - Brown Patch - Black Spot - Botrytis - Copper Spot - Dollar Spot - Downy Mildew - Fairy Ring - Fusarium - Leaf Spot - Pink Snow Mold - Pseudomonas - Pythium - Phytophthora - Powdery Mildew - Rhizoctonia - Rust - Scab - Slime Molds - Smut - Summer Patch - Thielaviopsis - Wilts & Blights - and other plant pathogenic fungal and bacterial spores

Bedding plants, Flowering plants, Roses, Poinsettia, Ornamentals, Nursery stock, Trees, Turf, Cut flowers, Bulbs, Cuttings, Seedlings and Seeds


Spray or drench

BioSafe Systems LLC

22 Meadow Street

East Hartford, CT 16108

Endomycorrhizae to increase plant nutrition and help protect against disease:

Glomus sp.(VAM fungus): Bioscientific (Mycorise) • BioOrganic • Green Releaf(BioReleaf) • Mikro-Tek • Plant Health Care (Mycor) • Biological Crop • Natural Fertilizer • Philom (TagTeam) • Rincon-VitovaAgBio • Roots • Mycorrhizal Applications

Ectomycorrhizae (forest nurseries, urban trees):

Pisolithustinctorius: Rincon-Vitova • Plant Health Care (Mycortrees) • Plant Revolution • AgBio • Mycorrhizal Applications Pisolithus, Rhizopogon mixtures: Roots • Plant Health Care

Microbial Soil Amendments:

New Era Farm Service (composted soil amendments) • Jade Mountain (composting toilet) • Northeast Organics (Turf Cocktail to stimulate microbials in soil) • Lane • AgroDist

Beneficial microorganisms that attack

turf pathogens:

Gardener’s Supply (Green Magic) • Green Releaf (BioReleaf) • Peaceful Valley (Restore) • Wilbur-Ellis (BioTrek) • Bioworks (Turfmate) • Eco-Soil (BioJect) • Soil Technologies (BacPack) • Natural Fertilizer • Plant Health Care (Compete)

Disease-suppressive container mixes or compost:

BioCompEarthgro (Scotts) • Sun-Gro • Southern • Louisiana Pacific • O.M. Scotts (Hyponex) • Paygro


Needle Cast Diseases of Conifers
Printable version of Needle Cast Diseases of Conifers (PDF)

Needle Cast Diseases of Conifers

Primary Hosts

Fungus/Disease Name

Infection Period/Fruiting Bodies


Needles Shed Timing

Scots pine, ponderosa pine


Late summer - early fall

Small, gray or black, football-shaped hysterothecia visible to the naked eye. When mature, these protrude slightly, and the epidermis ruptures to form a slit.

Winter- early spring

Yellow and reddish-brown spots on the needles, some of which may have yellow margins. Eventually, the entire needle will turn yellow, then reddish brown.

Mid-late spring

Ponderosa, lodgepole pines


Mid - late summer

Long black slit in epidermis near needle base

Early spring

Needles red-brown at tips, base remain green, witches brooms

12-20 months after infection

Ponderosa, Austrian, mugo pines




Black dots erupting thru epidermis in bands

Late summer - early fall

Distinct red transverse banding on tan needles


Lodgepole pine , limber pine


Late spring - early summer

Small depressions in leaf surface

Early – late spring

Dead, reddish-brown, then straw colored.


Douglas fir


Late spring – summer

Tan slits on underside of needles

Late summer - early fall

Yellow lesions followed by purple-brown spots and bands


Douglas fir

Swiss Needle cast

Late spring – early summer

The tiny black dots emerge through the stomata in rows on the underside on either side of the midrib.

Within a year

New needles become yellow overall although they occasionally turn brown general chlorosis or red-brown tips

1-3 years after infection




Dark, elongate pycnidia down center of lower surface of needles . Brown line on upper surface. Pustule like.


Needles become pale and patchy green and slowly turn brown.

2 years after infection


Rhizosphaera/ Stigmina

Spring – Fall

Black dots in stomata in rows

Late winter-early spring

Yellow to reddish-purple to brown

Late summer - Fall


Sudden Needle Drop


Black specks (perithecia) on twigs

Unknown (late winter – early spring)

Older needles are affected. Turn yellow to reddish-purple to brown similar to other spruce diseases

Unknown (late summer – early fall)

All species

Seasonal Needle Cast



Inner most needles suddenly turn brown. Needle retention depends on species and environment.


Powdery Mildew (Colorado State Extension)

Printable version of Powdery Mildew Colorado State Extension (PDF) 

Powdery Mildews

2.902 Fact Sheet No. Gardening Series|Diseases

by B. Edmunds and L.P. Pottorff*

Powdery mildews are one of the most widespread and easily recognized plant diseases. They affect virtually all kinds of plants: cereals and grasses, vegetables, ornamentals, weeds, shrubs, fruit trees, and broad-leaved shade and forest trees. In Colorado, powdery mildews are common on ash, lilac, grape, roses, turfgrass, vegetables (such as cucurbits and peas), euonymus, cherry, apple, crabapple, pear and Virginia creeper, among others.


Even though there are several types of powdery mildew fungi, they all produce similar symptoms on plant parts. Powdery mildews are characterized by spots or patches of white to grayish, talcum-powder-like growth. Tiny, pinhead-sized, spherical fruiting structures that are first white, later yellow-brown and finally black, may be present singly or in a group. These are the cleistothecia or overwintering bodies of the fungus.

The disease is most commonly observed on the upper sides of the leaves. It also affects the bottom sides of leaves, young stems, buds, flowers and young fruit. Infected leaves may become distorted, turn yellow with small patches of green, and fall prematurely. Infected buds may fail to open.

Conditions That Favor the Disease

The severity of the disease depends on many factors: variety of the host plant, age and condition of the plant, and weather conditions during the growing season.

Powdery mildews are severe in warm, dry climates. This is because the fungus does not need the presence of water on the leaf surface for infection to occur. However, the relative humidity of the air does need to be high for spore germination. Therefore, the disease is common in crowded plantings where air circulation is poor and in damp, shaded areas. Incidence of infection increases as relative humidity rises to 90 percent, but it does not occur when leaf surfaces are wet (e.g., in a rain shower). Young, succulent growth usually is more susceptible than older plant tissues.

About the Fungi

Powdery mildews are host specific – they cannot survive without the proper host plant. For example, the species Uncinulanecator, which causes powdery mildew on grape and linden, does not attack lilac. Similarly, Microsphaeaalniaffects elm, catalpa, lilac and oak but not turfgrass.

Powdery mildews produce mycelium (fungal threads) that grow only on the surface of the plant. They never invade the tissues themselves. The fungi feed by sending haustoria, or root-like structures, into the epidermal (top) cells of the plant. The fungi overwinter on plant debris as cleistothecia or mycelium. In the spring, the cleistothecia produce spores that are moved to susceptible host tissue by splashing raindrops, wind or insects.



Several practices will reduce or prevent powdery mildews. Many plants, such as roses, vegetables and Kentucky bluegrass, are developed to be resistant or tolerant to powdery mildew. Inquire about resistant varieties before a purchase. If resistant

Quick Facts

  • Powdery mildew is one of the most widespread and easily recognized plant diseases.
  • Powdery mildews are characterized by spots or patches of white to grayish, talcum-powder-like growth.
  • Powdery mildews are severe in warm, dry climates
  • Many plants have been developed to be resistant or tolerant to powdery mildew.
  • Succulent tissue is more susceptible to infection. Once the disease is a problem, avoid late summer applications of nitrogen fertilizer.
  • Plant resistant varieties if available.
  • Chemicals are most effective when combined with cultural controls.

©Colorado State University Extension. 10/99. Reviewed 5/09.


*Colorado State University Extension regional specialist, commercial greenhouse and nurseries, Adams County. Originally written by Laura Pottorff, former plant pathologist and horticulturist, Integrated Pest Management Program, Jefferson County. 5/09

varieties are unavailable, do not plant in low, shady locations.

Once the disease becomes a problem:

  • Avoid late-summer applications of nitrogen fertilizer to limit the production of succulent tissue, which is more susceptible to infection.
  • Avoid overhead watering to help reduce the relative humidity.
  • Remove and destroy all infected plant parts (leaves, etc.). For infected vegetables and other annuals, remove as much of the plant and its debris in the fall as possible. This decreases the ability of the fungus to survive the winter. Do not compost infected plant debris. Temperatures often are not hot enough to kill the fungus.
  • Selectively prune overcrowded plant material to help increase air circulation. This helps reduce relative humidity and infection.


If cultural controls fail to prevent disease buildup or if the disease pressure is too great, an application of a fungicide may be necessary. These include:

  • sulfur
  • neem oil (Rose Defense, Shield-All, Triact)
  • triforine (Ortho Funginex), ornamental use only
  • potassium bicarbonate (Kaligreen, First Step)

Chemicals are most effective when combined with cultural controls. Apply fungicides at seven to 14-day intervals to provide continuous protection throughout the growing season. Follow the instructions on the fungicide label for use on specific plant species, varieties, rates to be used, timing of applications, and waiting periods before harvest.

An alternative nontoxic control for mildew is baking soda (similar to the potassium bicarbonate listed above) combined with a lightweight horticultural oil (Sunspray). Researchers at Cornell University have discovered the fungicidal properties of this combination against powdery mildew on roses. Applications of one tablespoon baking soda plus 2.5 tablespoons of Sunspray oil in 1 gallon of water are still experimental. Use it at your own risk.

Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. CSU Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

Raspberry Cane Borer (New Hampshire)

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Raspberry Cane Borer


Though damage from the raspberry cane borer is often seen, the insect itself is rarely

recognized as a pest. It usually causes only slight or occasional injury, although, when abundant,

it can cause considerable damage. It is easy to control.


The adult cane borer is a slender, black beetle with long, black antennae, black head and

yellow prothorax. Adults are about one half an inch long. The larvae are legless, light-colored

borers found within the stem. Fully grown larvae are about 3/4 inch long.

Life Cycle

This insect has a two-year life cycle. Adults emerge beginning

in June and females lay eggs in the pith of new raspberry

growth, about six inches from the tip of the cane. The female

beetle then makes two rows of punctures around the cane, one

just above and one just below the egg-laying point. This

causes the tip of the new cane to wilt. The egg hatches in

early July and the larva burrows slowly down the cane, passing

the first winter within and inch or two of the girdle. During

the second year the larva burrows down to the crown and passes the second winter at or

below ground level. It completes its development the following spring and pupates in the soil.


Chemicals are not necessary to control this pest. Cut girdled canes an inch or so below the

girdle and burn them soon after cane borer damage appears. Attacked canes wilt, making the

damage easy to spot. Eliminating wild raspberries nearby will reduce damage. Since the life

cycle requires two years to complete, regular pruning usually keeps the population in check.

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Cane borer damage

The Use of BT for Spurce Bud Worm

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Bt biopesticide – marvel or mistake?

Conventional pesticides such as DDT and organophosphates have not only become less

effective as target insect populations evolve resistance, but have killed non-target predators

and parasites that otherwise keep pest insects in balance. Thus, under some conditions, pest

populations have exploded to uncontrollable levels, decimating whatever crops or gardens

they happen to feed upon. Furthermore, these persistent pesticides have accumulated

throughout aquatic and terrestrial food webs (connected food chains within an ecosystem),

creating ecological imbalances and impairing human health. Global concerns regarding

pesticide resistance, environmental degradation, and human health problems have led to the

development of biologically based, narrow-spectrum pesticides with fewer long-term hazards.

Over the last several decades, more farmers, forest and landscape managers, and gardeners

have turned to these more environmentally friendly methods of pest control, including Bt.

An introduction to Bt

Bt is an acronym for Bacillus thuringiensis, a naturally occurring species of bacteria found

world-wide in the soil and on plants. Nearly 100 years ago, this bacterium was discovered to

have pesticidal properties if consumed by the larvae of specific insects. Many subspecies,

varieties, and strains of Bt have been identified since then, and it’s likely many others have

yet to be discovered. Though genes from Bt have also been used in genetically modified

organisms, this article will focus only on the use of the microbe as an applied insecticide.

The strains of Bt characterized so far affect members of three insect Orders: Lepidoptera

(butterflies and moths), Diptera (mosquitoes and biting flies), and Coleoptera (beetles).

Commercially-available, EPA-registered Bt products include:

B.t.aizawai(Lepidoptera) – used for wax moth larvae in honeycombs

B.t.israelensis(Diptera) – frequently used for mosquitoes (see sidebar at end)

B.t.kurstaki(Lepidoptera) – frequently used for gypsy moth, spruce budworm, and

many vegetable pests

B.t. san diegoand tenebrionis (Coleoptera) - frequently used for elm leaf beetle,

Colorado potato beetle

B.t.kurstakiis the most commonly used Bt formulation, as it will kill many leaf-feeding

larvae on vegetables, shrubs, fruit trees and conifers. There is abundant scientific literature

on this biopesticidal organism.

Other Bt isolates have been characterized but not yet registered by the EPA. These include:

B.t.galleriae(Coleoptera) – used on Japanese beetles

B.t.japonensisand kumamotoensis – (Coleoptera) – used on several turf beetle species

Local isolates of Bt probably represent an underutilized, yet powerful, biological control

resource. In China, 30 new strains of Bt were isolated from drylands, gardens, and rice fields;

from these, one highly toxic strain was able to kill 100% of treated diamondback moth larvae

(Plutellaxylostella). Similarly high toxicities were found in ten new Bt strains isolated from

leaf and soil samples in Poland and in four new strains discovered in Mexico. Local bacterial

populations have the advantage of being adapted to local insect host; thus, it is logical to

expect to find powerful biocontrol agents in the pest’s backyard.

Mode of action

Bacillus thuringiensis strains produce crystalline proteins (called δ-endotoxins) that, when

consumed by particular insect larvae, have a poisonous effect upon the lining of the gut.

While some of the toxicological details are still a topic of scientific debate, we do know that

the crystalline proteins manufactured by the bacteria are toxic, causing the cell membranes

in the gut to split open and thus kill the larvae. The specificity of these toxins for insect

physiology means that other animals are not affected by the bacteria.

Bt found naturally on or applied to leaf surfaces must be ingested by the feeding form or an

insect (the larvae) to have an effect; in other words, Bt has no effect on adult insects.

Susceptible larvae that ingest the toxin are not killed immediately, but die over the next few

days. They do stop feeding, however, and thus plant damage is halted. Larvae that survive

the toxin may be more susceptible to other environmental stresses, such as cold temperatures

or low levels of botanical insecticides. This type of synergistic effect underscores the

importance of utilizing Bt as part of an integrated pest management plan.

Some insects have already developed resistance to Bt, most importantly the diamondback

moth (Plutellaxylostella), regarded as one of the most destructive crop pests worldwide. It

is a particularyresiliant species, reported to be the first insect to develop resistance to DDT

and almost every other synthetic insecticide. Bt-resistant insects apparently are able to

detoxify the bacterial proteins quickly and thus survive. Interestingly, Bt resistance appears

to harm the insect’s fitness when Bt is not present; in other words, resistant individuals do

not reproduce well so that resistance is quickly lost in the larger population when Bt is not

applied. This “resistance instability” may explain why Bt resistance is uncommon in pest

insect populations.

Human health and safety

All strains, subspecies, and varieties of Bt used as pesticides must be extensively tested for

both human and environmental safety. Regulatory agencies, such as the USEPA, require

thorough evaluations of the active microbial ingredient before they can be registered as

pesticides. Bacillus thuringiensis has been extensively used for four decades in biopesticidal

formulations due to its environmental and human health records.

Bt is considered to be “practically non-toxic” to humans and other vertebrates. It can cause

a “very slight irritation” if inhaled, and can cause eye irritation. These acute effects are

considered to be minor; there are no chronic toxicities. Bt is not carcinogenic, mutagenic, or

teratogenic: in other words, it does not cause cancer, induce chromosomal mutations, or

lead to birth defects in exposed animals.

Bt does not persist in the brains, lungs, or digestive systems of animals including humans.

While Bt has been found in fecal samples of exposed greenhouse workers, no GI symptoms

were associated with its presence. In fact, Bt appears to be a normal component in the feces

of vegetable-consuming animals, where it apparently causes no problem. Since Bt is a

normally-occuring bacteria often found on leaf surfaces, this should not be a surprise or a

cause for concern.

Like the active bacterial ingredient, the inert ingredients in Bt formulations have also been

studied and modified for safety. Newer formulations employ preservatives, like sorbitol, that

are safer than the xylene used decades ago. Likewise, granular and microcapsule

formulations reduce the inhalation hazard. Volatile agents associated with some Bt

formulations likewise do not appear to constitute a significant health hazard.

In the 50 years that Bt has been used for insect control, there have been few reports of

human pathogenicity, suggesting that the commercially available products are free from non-

Bt microbes and can be safely used around people. In contrast, there are often significant

human health risks associated with the pest insects themselves. Many larvae are protected by

urticating (barbed) hairs, which can irritate skin and mucous membranes. Dermatitis,

conjunctivitis, and/or respiratory disorders have resulted in people who have been in contact

with pine processionary moth Thaumetopoeapityocampa, cypress processionary moth

Thaumetopoeawilkinsoni, and grapeleafskeletonizerHarrisinabrillians.

Environmental and ecological impacts

In addition to their excellent record on human health, Bt products are globally recognized by

researchers in many disciplines as an environmentally safe means of controlling pest insects.

There is an extensive and reliable body of science demonstrating the environmental safety of

Bt, allowing governmental and health organizations to recommend their use on a variety of

landscapes worldwide.

Specifically, no danger has been found to aquatic communities accidentally exposed to Bt

(but see sidebar) or to non-target organisms including beneficial insects, amphibians, fish,

and mammals. A number of researchers have demonstrated the general safety of Bt

formulations to natural predators of pest insects. By and large, these predators belong to

different orders than those affected by most Bt formulations, including spiders (Araneae),

ladybugs (Coleoptera), true bugs (Hemiptera), and ants (Hymenoptera).

There are few reports of Bt lethality upon non-target organisms, such as leaf-feeding

caterpillars. Another researcher has suggested that clay soils may bind the bacterial toxin,

increasing its environmental persistence and possible toxicity to non-target species. Though

the preponderance of the evidence does not agree with these reports, all researchers concur

that Bt monitoring must continue to explore these exceptions and to modify Bt usage as


Urban use

Increasingly, land managers are recognizing the environmental advantages of reduced

chemical treatments in urban areas. Given their extraordinary record in human and

environmental health and safety, Bt products are increasingly applied to urban parks and

landscapes to control gypsy moth (Lymantria dispar), cypress and pine processionary moth

(Thaumetopoeawilkinsoniand Thaumetopoeapityocampa), fall webworm (Hyphantriacunea)

and other nuisance insects. These insects are of particular concern because of their abilities

to denude trees, invade woodpiles, houses, and vehicles in search of pupation sites (fall

webworm), and cause human health problems as mentioned earlier.

Bt use in urban areas requires a significant public education effort. This was illustrated

several years ago when citizens and environmental groups became upset with the aerial

spraying done in parts of Oregon and Washington to control invasions of gypsy moths

(Lymantria dispar) and attempted to get an injunction to halt spraying. The presiding judge

found no scientific proof that Bt was hazardous to people and that the eradication of the

moth populations was of greater environmental concern. Obviously, close communication

with the public is critical when Bt products are used, so that environmental and health

concerns can be addressed. In addition, governmental organizations must be proactive in

enforcing safety regulations and establishing buffer zones in populated areas to reduce

perceived risk and engender citizen trust.

Unfortunately, some gray literature (i.e. not peer-reviewed) ignores the decades of scientific

research on Bt and instead uses scare tactics against Bt. These unbalanced articles serve only

to upset the general public and do not advance either the research, or the discussion, that

must continue to take place regarding Bt and other biopesticides. It is naïve to assume that

growers and landscape managers will give up Bt and simply sit back to watch their livelihood

collapse; if safe and practical alternatives are not available, they will resort to conventional

methods. This is not the direction we need to move.

Bt as part of an Integrated Pest Management (IPM) program

Like any other pest control method, Bt works best as part of an integrated management plan.

The philosophy of such a plan is to reduce pests to acceptable levels, not to eliminate them

completely. As we’ve discovered – much to our detriment - attempts to exterminate pests

result in resistant pest populations and environmental degradation.

Bt has become a cornerstone of IPM systems, accounting for more than 90% of the biological

insecticides currently used. Though Bt has been used successfully by itself, the practice of

IPM generally incorporates Bt, with other biological, cultural, mechanical, and chemical

controls. A great deal of research worldwide has explored the use of Bt in concert with these

associated methods:

Cultural: Crop rotation; minimium tillage; shelter strips

Mechanical: Removal of pest (eggs and larvae); removal of infested materials

Biological: Parasitoids; pathogens, including Bt, fungi, granulosis virus and

nucleopolyhedrosis virus; predators

Chemical: Botanical insecticides such as neem; pheromone baiting/mating disruption;

pyrethrins and pyrethroids

Practical considerations

Like any other living organism, Bt activity is affected by environmental factors including

temperature, rainfall, pH, and sunlight. Bt applied to leaf surfaces, for example, can be

degraded by solar UV or washed off by irrigation or rainfall. Many of these limitations have

been addressed through the development of new Bt formulations that protect the organism

from deactivation. Still, there are other factors that influence effectiveness of this

biocontrol agent.

Only the feeding larval stage is susceptible to Bt, and thus timing of application is of

paramount importance. While this may be during the spring for many leptidopteran pest

species, for coleopteran pests in turf application is only effective in the fall. Cold weather

decreases effectiveness, perhaps because larval feeding activity is reduced.

Location of the target insect also influences Bt effectiveness. Boring insects, though

susceptible to Bt in laboratory trials, can escape Bt exposure if feeding in protected sites.

Likewise, it is difficult, if not impossible, to spray the crowns of tall trees from the ground.

In such cases, a cherry-picker could be used for spraying individual trees, but larger areas are

more effectively managed through aerial spraying.

As with any other pesticide, Bt must be considered as an option, not a magic bullet, for pest

management. Consumer education is critical in this regard to avoid improper or

overapplication of Bt. Misapplication of Bt at the wrong time or on the wrong species can

lead to pest resistance.

Economic feasibility

In its infancy, use of Bt was costly to produce and to apply; while formulation is still

expensive, new production techniques have been developed that promise to lower the cost in

developing countries. Bt is more cost effective to use now, since application costs have

decreased. Proponents hope that the environmental and human health benefits would more

than offset the economic costs.

Indeed, the economic comparisons between conventionally managed and IPM (including Bt)

fields have demonstrated that not only was insect damage reduction approximately the same,

but that IPM net profits were greater because of reduced insecticide costs. Though not

included in these studies, the more intangible benefits associated with Bt-treated fields—such

as reduction in pesticide resistance, less environmental damage, fewer human health risks—

cannot be ignored and must be emphasized.

The big picture

There is no question that broad-spectrum, conventional pesticides can cause more problems

than they solve. Not only is the pest killed, but so too are the beneficial predators and

parasites, leading to future outbreaks of resistant pest populations. The negative, longlasting

effects of these pesticides on human and environmental health should not be ignored

or considered collateral damage.

Once insects become resistant to chemical pesticides, the usefulness of that compound is

finished, at least temporarily. The elegance of biocontrol systems, like Bt, is that the

pesticide is a living organism – one that can evolve as its host becomes resistant. New strains

of Bt and related species are discovered routinely. These specifically-targeted compounds

are considered by the scientific community to be environmentally friendly, with little or no

effect on humans, wildlife, pollinators, and most other beneficial insects. We continue to

discover what we’ve always known—that it’s easier to work with nature than against it.

Sidebar: Bt for mosquito control

Perhaps nowhere has Bt usage had such dramatic effects as in fighting mosquitoes and the

illnesses they carry. Historically, mosquitoes have been implicated as transmitters for

malaria, encephalitis, and dengue fever, but more recently have been recognized as the

carriers of West Nile viruses and many other viruses, pathogens, and parasites. Mosquitoes of

in the genera Aedes, Anopheles, Culex, Psorophora, and Stegomyia cause much human misery

and have high societal costs associated with them.

Bacillus thuringiensis israelensis, or Bti, has been used effectively to kill many species of

mosquitoes within these genera, as well as other biting flies in the Order Diptera worldwide;

this has been demonstrated repeatedly through field studies in Africa, Asia, Australia, Eastern

and Western Europe, India, and North America. Though not registered by the USEPA, B.t.

sphaericus (Bs) also has activity against mosquito larvae, as does B.t.jegathesan. Field tests

have shown significant reductions in both mosquito numbers and associated malarial cases.

Formulations are important with Bt products applied to aquatic systems. Dry preparations

tend to be less successful, as the spores settle to the bottom and are not eaten by larvae,

which tend to be near the surface of the water. Biofilms, fizzy tablets, and slow-release

floating rings are more effective in this regard. The latter two formulations are readily

available, inexpensive, and can be easily handled and applied by volunteers. They should be

used anywhere that standing water – and mosquito larvae – accumulates. Treatments often

need to be repeated to treat subsequent hatchings.

Though some mosquitoes have developed resistance to some Bacillus species, applying these

biopesticides in rotation has overcome resistance. Use of other IPM choices, such as

predatory fish, can help reduce larval numbers. Finally, new strains of Bti and Bs are

constantly being discovered in rice fields, plantations, gardens, and other habitats with

standing water.

Bti has generally been seen to be safe for non-target aquatic organisms, such as dragonflies,

damsel flies, notonectid bugs, fishes, frogs and birds, according to the majority of studies

that have been performed. Conflicting information comes from two studies in Minnesota: one

over 3 years and the second over 6 years. The shorter of the studies reported severe declines

in Diptera species, causing the authors to question the environmental safety of Bti. However,

the longer study found no negative effects on zooplankton or bird populations resulting from

insect decreases. These authors noted that the ecological complexity of wetland food webs

and/or other environmental factors could nullify the impact of reduced insect numbers.

Indeed, the first authors acknowledged that droughty years would cause a similar decline in

insect populations, a completely natural situation from which one would expect the system to


Conventional mosquito treatment has usually consisted of DDT, a highly toxic, broad-spectrum

pesticide whose residues persist throughout food chains decades after their application.

Though banned in the US since 1973, DDT is still legally applied to many regions of the world

where malaria is a problem. Less devastating are the synthetic pyrethroids, which still kill

about 150-200 non-target organisms for each adult mosquito killed. In comparison, Bt

products represent a much gentler approach to mosquito management.

Dr. Linda Chalker-Scott, PhD

Associate Professor and Extension Urban Horticulturist

WSU Puyallup Research and Extension Center

7612 Pioneer Way E

Puyallup, WA 98371

Phone: (253) 445-4542

Email: [email protected]

Western Spurce Bud Worms

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Western Spruce Budworms

by D.A. Leatherman, J.W. Brewer and R.E. Stevens 1 (2/09)

Quick Facts...

 Western spruce budworms are the most important tree defoliators in the West.

 Budworm larvae eat the new growth of host trees.

 Douglas-fir is the favored host in Colorado.

 Budworm has a one-year life cycle.

 Budworm control measures usually are conducted in June.

Description and Life Cycle

The western spruce budworm, ChoristoneuraoccidentalisFreeman, is the most widely distributed and destructive forest defoliator in western North America. Several outbreaks have occurred in Colorado, the largest exceeding two million acres. In Colorado, they most commonly infest Douglas-fir and white fir. Occasionally, they also attack Engelmann spruce, blue spruce and subalpine fir.

Western spruce budworm adults (Figure 1) normally are small, mottled, rusty-brown moths, but color can vary from tan to almost black. In Colorado, they are present from late June to early August. After mating, females lay masses of overlapping green eggs on the undersides of needles (Figure 2). The masses consist of 25 to 40 eggs that hatch in about 10 days. The young larvae do not feed but move to crevices under bark scales or lichens where they spin silken shelters called hibernaculae. There they remain dormant throughout the winter.

In late April or May, the larvae migrate to the foliage, where they mine old needles or feed on host tree flowers. In a week or two, they enter developing buds, the habit that gives them their name. As the new needles lengthen, the rapidly growing larvae continue to feed. It is during this stage that most of the damage occurs. They web the new foliage together loosely and feed inside, where they are somewhat protected from predators and other enemies.

In the late larval stages (Figure 3), budworms have brownish heads and brownish-olive bodies. Each body segment has two conspicuous pairs of white spots. About 40 days after feeding begins in the spring, usually about the end of June, the larvae pupate inside feeding webs or on foliage. Adults emerge a week or so later and the cycle is complete. There is one generation per year.

Damage and Associated Impact

Budworms are important because they can eat all the new growth produced by host trees. The new needles are most important in producing food for the tree, so the immediate effect of defoliation is a reduction in growth.

To the homeowner, defoliation mostly means a loss of aesthetic value. As defoliation progresses, both in extent and duration, more significant impacts are likely. The foliage, especially the branch tips, turns brown and dies. Twigs, branches or entire tops of trees may be killed. During long-running outbreaks, three to five years or more, may trees will die. Nonfatal defoliation may also lead to infestation by the Douglas-fir beetle or other bark beetles. In turn, these can kill the tree.


Budworms like forest stands that are dense, dominated by host species of all sizes, surrounded by similar forests, and stressed. Silviculture practices that thin forests, convert them to nonhost species, or limit host species to one size help prevent serious damage. This is the long-term solution to budworm.


Budworm populations usually are held in check by a combination of predators, parasites, adverse climatic conditions, or inadequate food supply. Spiders, insects and a variety of birds are important predators. Adverse weather conditions, particularly sudden freezes in late spring, may kill large numbers of larvae. A major factor in ending long-term outbreaks appears to be starvation from inadequate or nutritionally poor food sources. However, this may not be a factor in urban situations. Cultural practices such as thinning, watering and fertilizing, which promote tree vigor, may help trees better withstand repeated attacks.

Chemical control often is used to protect high-value trees from defoliation and associated damage. The materials listed below are registered for western spruce budworm control and have been used with success in Colorado. They can be applied both from the ground and aerially. In either case, time spraying to occur during the two to three weeks immediately following bud break or flush of new growth. In most years, this occurs about mid-June.

Table 1: insecticides for control of western spruce budworm.


Trade name

Bt (Bacillus thuringiensis)

Dipel, Thuricide, Biobit, Foray (aircraft spraying)



Related Insects

A close relative of western spruce budworm, the so-called pine budworm, Choristoneuralambertianaponderosana(Obraztsov), also is present in this area (See fact sheet 5.567, Ponderosa Pine Budworm). This species attacks pines, especially ponderosa pine, and occasionally causes serious damage to individual trees. However, it is not normally an important defoliator in the urban environment.


Fellin, David G. and Jerald E. Dewey, Western Spruce Budworm. USDA Forest Service, Forest insect and Disease Leaflet 53, 1982.

 Furniss, R. L. and V. M. Carolin. Western Forest Insects. USDA Forest Service Miscellaneous Publication No. 1339, 1977.

1 D.A. Leatherman, Colorado State Forest Service entomologist; J.W. Brewer, Colorado State University former professor, zoology and entomology; and R.E. Stevens, former Rocky Mountain Forest and Range Experiment Station entomologist. 2/99. Reviewed by I. Aguayo, forester, Colorado State Forest Service. 2/09.

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White Bryony

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White Bryony (Bryonia alba)

Monthly Weed Post October 2011

White bryony is a poisonous plant with foliage and fruit that closely resembles edible grapes. We hope this Monthly Weed Post will help people recognize white bryony that might be growing in their yard or neighborhood. Identification is especially important for those of you who like to forage or have small children that could mistake white bryony for grapes or other edible fruit.

Identification: White bryony is a non-native perennial herbaceous vine. Leaves are simple, palmate, and broadly toothed. Flowers are greenish white or pale yellow, up to ½ inch in diameter. Berries are initially light green, and change to black when mature (Figure B), closely resembling a Montana native, riverbank grape (Vitisriparia. Figure E). Unlike riverbank grape, white bryony has small white glands or dots on the surface and underside of the leaves (Figure C). White bryony does not have a woody stem like riverbank grape (Figure D).

White bryony (A, B, C) Riverbank grape (D, E, F)

Impacts: Described as the “Kudzu of the West” white bryony grows rapidly, as much as 6” per day. Infestations growing on small trees and shrubs can eventually block all light to the host plant. Dense infestations of white bryony on shrub or tree hosts causes snow to accumulate on the limbs, leading to breakage or loss of branches, which can make the host susceptible to disease and insects. White bryony berries are poisonous. Human fatality has been reported when less than 40 berries were consumed.

Habitat: The plant generally occurs as a climber in trees and fence rows. It was introduced as an ornamental and used primarily in horticultural plantings, so it is commonly found in yards and old homesteads.

Spread: Birds consume the seed and spread it widely. The plant is often found growing beneath places where birds perch such as fencelines, trees, and powerlines.

Management Priorities: White bryony is not listed as a noxious weed in Montana, but it is listed in Idaho. If you find this plant in your neighborhood, we strongly recommend removing it. Digging up the root is the most effective control method and should be done in autumn after the leaves have died back. The roots must be severed 3-4 inches below the soil surface. Watch for new plants or re-growth and repeat root severing as often as necessary. Wear protective gear (gloves, long sleeves, etc.) when handling the plant as it can irritate the skin. Monthly Weed Post October 2011 2

Weed Post Puzzle: Test your knowledge of white bryony












1 – Color of immature white bryony berries

3 - Thinking of making jam or wine from this plant? Think again—40 berries from this plant may be fatal

5 - Both white bryony and grape vines have this feature to help them cling to and climb up structures

7 – White bryony should not be confused with this edible Montana native

9 - Best time of year to sever white bryony roots

10 - White bryony's rapid and aggressive growth rate is similar to this invasive vine of the eastern U.S.

1 - These dots are on both sides of a white bryony leaf, but not riverbank grape leaves

2 - Some birds' favorite roost, white bryony is commonly found beneath these in suburban alleys (two words).

4 - Use these when handling white bryony to avoid skin irritation

5 - Sever the root at least _____ inches below the soil to control white bryony

6 - White bryony leaf shape

8 - Mature color of white bryony berries

Composting Article

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Beware of herbicide contaminated compost

Patricia McGlynn, PhD

Montana State University Agriculture Extension Agent

May 3, 2011

A problem that is becoming an increasing concern is herbicide damage on vegetable plants in backyard gardens. Many homeowners are adding composted manure to their gardens to improve the health of their soil. Compost potentially adds beneficial nutrients and micorrhizal fungus. When the manure has been contaminated by herbicides, it can prove deadly to the vegetable crop.

Stronger herbicides are being used to control noxious weeds in lawns, roadsides and hay fields. A number of these herbicides are exhibiting a long residual in both living and dead plant material. The herbicide will stay active, even though it has passed through the digestive tract of an animal and has been in a compost pile for up to three years, according to the Montana Dept of Agriculture. At a rate of only one part per billion, the herbicides picloram, clopyralid and aminopyralid will damage vegetables and landscape ornamentals.

It is extremely important to know where your manure compost comes from and what the animal has been eating. Certified weed free hay is good for preventing the spread of noxious weeds into our natural areas, but not good for your garden. Many of these hay fields have been sprayed with herbicides to control weeds and this will end up passing through the horses. Cattle can consume herbicides by grazing along treated roadways and fence lines. There was an unfortunate contamination of an organic vegetable farm in the Bitterroot last summer, when a livestock producer unknowingly purchased contaminated hay and fed it to his cattle. An organic farmer bought the manure and spread it on her fields. It will be years before these fields will be able to produce vegetables again.

If you are using chemicals, such as Milestone, to control weeds in your lawn or roadways, follow the instructions on the label. It will tell you how long the residual is and not to compost this material. Homeowners need to be careful adding grass clippings to the garden or compost pile that may have had herbicide treatments. If in doubt, do not use lawn clippings.

In the Flathead Extension office, we received over two dozen plant samples that exhibited herbicide damage last year. A percentage of the symptoms were attributed to overspray and the rest were from contaminated compost. The trade names of the herbicides with long residuals are:

 Picloram - sold as Tordon, Access, Surmount, Grazon, and Pathway.

 Clopyralid - sold as Curtail, Confront, Clopyr AG, Lontrel, Stinger, Millennium Ultra, Millenium Ultra Plus, Reclaim, Redeem, Transline.

 Aminopyralid - sold as Milestone, Forefront, Pharaoh, Banish.

The garden plants most sensitive to these herbicides are:

 Legume family - including lupines, peas, beans and clover.

Compositae family - including daisy, aster, sunflower and lettuces.

 Nightshade family - including tomatoes, potatoes, peppers and eggplants.

Umbelliferae family - including carrots.

 Many other vegetables and flowers.

Sensitive plants that are exposed to these herbicides develop cupped or fern like leaves and twisted stems. The herbicides are growth inhibitors and affect the development of leaves and flowers. The theory behind these products is that they are safer for people or pets.

According to state researchers, the best way to test your compost is this bioassay method.

  1. Thoroughly mix 1-2 parts manure, compost or soil with 1 part commercial potting soil in a clean bucket. Prepare enough to fill three 4-inch pots.
  2. Fill another three clean pots solely with commercial potting soil. These will be the untreated comparisons.
  3. Place each of the pots in a separate saucer to prevent water from one pot reaching another.
  4. Water the pots and leave to stand for 24 hours.
  5. Plant each pot with three pea or bean seeds.
  6. Observe subsequent growth for four-week period and note any ill effects in the pots containing the possibly contaminated mix, such as cupped leaves, fern like growth on new shoots or twisted stems. These symptoms may indicate picloram, clopyralid or aminopyralid residue in the manure, compost or soil. Signs of other kinds of damage will most likely indicate other issues such as damping off or bacteria-infected soil, etc.

This message is not meant to discourage anyone from using composted manure. It is important that you know where your compost comes from. Once contaminated with an herbicide it can be years before you can grow certain crops in that area.

Happy Spring and Happy Gardening.

Frost Free Days Chart (MSU Creston Research Station)

Printable version of Frost Free Days Chart-MSU Creston Research Station (PDF)

Frost free period at the Northwestern Agricultural Research Center from 1980 - 2011













June 4


Sept. 24




May 5


Sept. 24




May 30


Sept. 15




May 15


Sept. 6




June 2


Sept. 13




May 13


Sept. 7




May 16


Sept. 7




May 22


Sept. 17




May 3


Sept. 12




May 21


Sept. 9




May 10


Oct. 6




May 27


Sept. 19




May 17


Aug. 24




May 4


Sept. 13




April 30


Sept. 12




May 27


Sept. 21




May 21


Sept. 23




May 21


Oct. 8




May 19


Oct. 5




June 7


Sept. 12




June 1


Sept. 22




May 20


Sept. 29




May 23


Sept. 21




May 20


Sept. 30




May 14


Oct. 1




May 24


Sept. 24




May 15


Sept. 17




May 7


Sept. 14




May 10


Sept. 14




May 2


Oct. 6




May 22


Sept 23




May 18


Sept 29



Median Date

for 1980-2011

May 19


September 24




Ground Squirls
Printable version of Ground Squirrels (PDF)




Leonard R. Askham

Professor Emeritus

Department of Horticulture and Landscape Architecture

Washington State University Pullman, Washington 99164-6414

Damage Prevention and

Control Methods


Limited usefulness.

Cultural Methods

Flood irrigation, forage removal, crop rotation, and summer fallow may reduce populations and limit spread.


None are registered.


Zinc phosphide.



Note: Not all toxicants are registered for use in every state. Check registration labels for limitations within each state.


Aluminum phosphide.

Gas cartridge.


Box traps.

Burrow-entrance traps.

Leghold traps.


Limited usefulness.


Cooperative Extension Division

Institute of Agriculture and Natural Resources

University of Nebraska - Lincoln

United States Department of Agriculture

Animal and Plant Health Inspection Service

Animal Damage Control

Great Plains Agricultural Council Wildlife Committee Identification

The Franklin ground squirrel (Spermophilus franklinii, Fig. 1) is a rather drab grayish brown. Black speckling gives a spotted or barred effect. Head and body average 10 inches (25.4 cm) with a 5- to 6-inch (12.7- to 15.2-cm) tail. Adults weigh from 10 to 25 ounces (280 to 700 g). The Richardson ground squirrel (S. richardson) is smaller and lighter colored than the Franklin. Some are dappled on the back. The squirrel’s body measures about 8 inches (20.3 1. cm) with a tail of from 2 to 4 inches (5 to 10 cm). Adults weigh from 11 to 18 ounces (308 to 504 g). The Columbian ground squirrel (S. columbianus) is easily distinguished from others in its range by its distinctive coloration. Reddish brown (rufous) fur is quite evident on the nose, forelegs, and hindquarters. The head and body measure 10 to 12 inches (25.4 to 30.5 cm) in length with a 3- to 5-inch (7.6- to 12.7-cm) tail. An average adult weighs more than 16 ounces (454 g). The Washington ground squirrel (S. washingtoni) has a small smoky-gray flecked body with dappled whitish spots. The tail is short with a blackish tip. This squirrel is similar to Townsend and Belding squirrels except the latter have no spots. Head and body are about 6 to 7 inches long (15.2 to 18 cm); the tail 1.3 to 2.5 inches long (3.4 to 6.4 cm); and adults weigh 6 to 10 ounces (168 to 280 g). The Townsend ground squirrel’s (S. townsendi) head and body range in length from 5.5 to 7 inches (14 to 18 cm). It has a short bicolored tail about 1.3 to 2.3 inches (3 to 6 cm) long, and weighs approximately 6 to 9 ounces (168 to 252 g). The body is smoky-gray washed with a pinkish-buff. The belly and flanks are whitish. Other species not described here because they cause few economic problems are Idaho (S. brunneus), Uinta (S. armatus), Mexican (S. mexicanus), Spotted (S. spilosoma), Mohave (S. mohavensis), and roundtail (S. tereticaudus) ground squirrels.


Ground squirrels are common throughout the western two-thirds of the North American continent. Most are common to areas of open sagebrush and grasslands and are often found in and around dryland grain fields, meadows, hay land, and irrigated pastures. Details of each species range, which overlap occasionally, are shown in figures 2 and 3.

Food Habits

Ground squirrels eat a wide variety of food. Most prefer succulent green vegetation (grasses, forbs, and even brush) when available, switching to dry foods, such as seeds, later in the year. The relatively high nutrient and oil content of the seeds aids in thedeposition of fat necessary for hibernation. Most store large quantities of food in burrow caches. Some species, like the Franklin, eat a greater amount of animal matter, including groundnesting bird eggs. Insects and other animal tissue may comprise up to onefourth of their diet.

General Biology, Reproduction, and Behavior

Ground squirrels construct and live in extensive underground burrows, sometimes up to 6 feet (2 m) deep, with many entrances. They also use and improve on the abandoned burrows of other mammals such as prairie dogs and pocket gophers. Most return to their nests of dried vegetation within the burrows at night, during the warmest part of summer days, and when they are threatened by predators, such as snakes, coyotes, foxes, weasels, badgers, and raptors. The squirrels generally enter their burrows to estivate, escaping the late summer heat. They hibernate during the coldest part of the winter. Males usually become active above ground 1 to 2 weeks before the females in the spring, sometimes as early as late February or early March. A few may be active above ground throughout the year. Breeding takes place immediately after emergence. The young are born after a 4- to 5-week gestation period with 2 to 10 young per litter. Generally only 1 litter is produced each year. Densities of the ground squirrel populations can range from 2 to 20 or more per acre (5 to 50/ha).

Damage and Damage Identification

High populations of ground squirrels may pose a serious pest problem. The squirrels compete with livestock for forage; destroy food crops, golf courses, and lawns; and can be reservoirs for diseases such as plague. Their burrow systems have been known to weaken and collapse ditch banks andcanals, undermine foundations, and alter irrigation systems. The mounds of soil excavated from their burrows not only cover and kill vegetation, but damage haying machinery. In addition, some ground squirrels prey on the eggs and young of ground-nesting birds or climb trees in the spring to feed on new shoots and buds in orchards.

Legal Status

Ground squirrels generally are unprotected. However, species associated with them, such as black-footed ferrets, weasels, wolves, eagles, and other carnivores may be protected. Local laws as well as specific label restrictions should be consulted before initiating lethal control measures.

Damage Prevention and Control Methods Exclusion

Exclusion is impractical in most cases because ground squirrels are able to dig under or climb over most simple barriers. Structures truly able to exclude them are prohibitively expensive for most situations. Sheet metal collars are sometimes used around tree trunks to prevent damage to the base of the trees or to keep animals from climbing trees to eat fruit or nut crops.

Cultural Methods/Habitat Modification

Flood irrigation of hay and pasture lands and frequent tillage of other crops discourage ground squirrels somewhat. Squirrels, however, usually adapt by building the major part of their burrows at the margins of fields, where they have access to the crop. During the early part of the season they begin foraging from the existing burrow system into the field until their comfort escape zone is exceeded. When this zone is exceeded and as the litters mature in the colony, tunnels will be extended into the feeding area. Late in the summer or fall, tillage will destroy these tunnels but will not disturb or destroy the original system at the edge of the field. Some research has been conducted on the effect of tall vegetation on ground squirrel populations and movements. The data, while sketchy, indicate that the squirrels may move out of tall vegetation stands to more open grass fields. The addition of raptor (hawk, owl, and kestrel) nest boxes and perches around the field border or throughout the colony may reduce colony growth, but is not a reliable damage control method.


Zinc phosphide and anticoagulants are currently registered for ground squirrel control. Since pesticide registrations vary from state to state, check with your local extension, USDA-APHISAnimal Damage Control, or state department of agriculture for use limitations. Additional restrictions may be in effect for areas where endangered species have been identified. Zinc phosphide has been used for several years to control ground squirrels. It is a single-dose toxicant which, when used properly, can result in mortality rates as high as 85% to 90%. If, however, the targeted animals do not consume enough bait for mortality to occur, they become sick, associate their illness with the food source they have just consumed, and are reluctant to return to the bait. This is called “bait shyness.” Repeated baiting with the same bait formulations is generally unsuccessful, particularly when tried during the same year. Prebaiting may increase bait acceptance with treated grain baits. Prebaiting means exposing squirrels to untreated grain bait several days before using toxic grain. Conditioning the squirrels to eating this new food improves the likelihood of their eating a lethal dose of toxic grain. Prebaiting often improves bait acceptance and, therefore, control. The major disadvantage is the cost of labor and materials for prebaiting. Zinc phosphide is classified as a Restricted Use Pesticide and as such, can only be purchased or used with proper certification from the state. Certification information can be obtained from your local Cooperative Extension or state department of agriculture office. Zinc phosphide can be absorbed in small amounts through the skin. Rubber gloves should be worn when handling the bait. Use only fresh bait. Spoiled or contaminated baits will not be eaten by ground squirrels. Old bait may not be sufficiently toxic to be effective. If zinc phosphide baits are more than a few months old they should not be used, particularly if they have not been stored in air-tight, sealed containers, because they decompose with humidity in the air. Chlorophacinone and diphacinone are two anticoagulant baits that have been registered in some states for ground squirrel control and have been found to be quite effective. Both are formulated under a number of trade names. Death will occur within 4 to 9 days if a continual supply of the bait is consumed. If baiting is interrupted or a sufficient amount is not maintained during the control period, the toxic effects of the chemicals wear off and the animal will recover. Baiting should not begin until the entire population is active, 2 to 3 weeks after the first adults appear. If a portion of the population is in hibernation or estivation, only the active animals will be affected. Bait selection should be based on the animal’s feeding habits, time of year, and crop type. Ground squirrel feeding habits vary with the time of year. Grain baits may be more acceptable during the spring when the amount of green vegetation is limited. Pelletized baits using alfalfa or grass as a major constituent may be preferred later in the season. It is important to test the acceptance of a bait before a formal baiting program begins. Place clean (untreated) grains by several active burrows. Use only grains acceptable to the animals as a bait carrier. If none of the grains are consumed, the same procedure can be repeated for pelletized baits. Several formulations may need to be tried before an acceptable bait is selected. If control with one bait is unsuccessful, rebaiting with another toxicant may produce the desired results. This is particularly important when zinc phosphide is used. Follow-up treatments with an anticoagulant will often control the remaining animals. Bait placement is critical. Bait should be scattered adjacent to each active burrow in the amount and manner specified on the label. It should not be placed in the burrow, because it will either be covered with soil or pushed out of the hole by the squirrels. Ground squirrels are accustomed to foraging above ground for their food and are suspicious of anything placed in their tunnel systems. All active burrows must be baited. Incomplete coverage of the colony will result in poor control success. Where broadcast applications are not allowed, baits can be placed in spillproof containers. Old tires have been extensively used in the past but are bulky, heavy, and time-consuming to cut apart and move. Furthermore, bait can easily be pushed out by the animals and the tires can ruin a good sickle bar or header if not removed from a field before harvest. Corrugated plastic drain pipe of different diameters cut into 18- to 24-inch (46- to 61-cm) lengths provide an inexpensive, light-weight, and easy-to-use alternative. Bait stations should be placed in the field at about 50-foot (15-m) intervals a week or so before treatments are to begin. Once the animals use the stations frequently, baiting can begin. Not all bait stations will be used by the squirrels at the same time or with the same frequency. Each station should be checked every 24 hours and consumed or contaminated baits replaced until feeding stops. When the desired level of control has been achieved, the bait stations should be removed from the field and the old bait returned to the original container or properly disposed.


Fumigants are best suited to small acreages of light squirrel infestations. Most are only effective in tight, compact, moist soils over 60o F (15o C). The gas dissipates too rapidly in loose dry soils to be effective in any extensive burrow system. Ground squirrel burrow systems are often complex with several openings and numerous interconnecting tunnels. The cost of using gas cartridges may be more than eight times the cost of using toxic baits. Fumigants registered for ground squirrel control include aluminum phosphide and gas cartridges. Cartridges may contain several combustible ingredients. When using aluminum phosphide, place tablets at multiple entrances at the same time. Insert the tablets as far back into the burrows as possible. Water may be added to the soil to improve activity. Never allow aluminum phosphide to come into direct contact with water, because the two together can be explosive. Crumpled paper should be placed in the hole to prevent the fumigant from being pushed out of the hole by the animals or being covered by loose soil. Plug the burrow opening with soil to form an air-tight seal. Monitor the area for escaping gas and plug holes as needed. When using gas cartridges, punch five or six holes in one end of each gas cartridge and loosen the contents for more complete combustion before use. Insert and light a fuse. Gently slide the cartridge, fuse end first, as far back into the burrow opening as possible and immediately seal the hole with soil. Do not cover or smother the cartridge. Follow all label instructions. Phosphine gas is toxic to all forms of animal life. Inhalation can produce a sensation of pressure in the chest, dizziness, nausea, vomiting, and a rapid onset of stupor. Affected people or animals should be exposed to fresh air and receive immediate medical attention. Never carry a container of aluminum phosphide in an enclosed vehicle.


Traps are best suited for removal of small populations of ground squirrels where other control methods are unsatisfactory or undesirable. Jaw traps (No. 1 or No. 0), box or cage traps, and burrow entrance traps may be used. Place leghold traps where squirrels will travel over them when entering and leaving their burrows. Conceal the trap by placing it in a shallow excavation and covering it with 1/8 to 1/4 inch (0.3 to 0.6 cm) of soil. Be certain that there is no soil beneath the trap pan to impede its action. No bait is necessary. Box or cage traps may be set in any areas frequented by ground squirrels. Place them solidly on the ground so that they will not tip or rock when the squirrel enters. Never place the trap directly over a hole or on a mound. Cover the floor of the trap with soil and bait it with fresh fruit, vegetables, greens, peanut butter, or grain. Experiment to find the best bait or combination of baits for your area and time of year. Wire the door of the trap open for 2 to 3 days and replenish the bait daily to help overcome the squirrel’s trap shyness and increase trapping success. Burrow entrance traps may also be useful. See Thirteen-lined Ground Squirrels for a description of this type of trap.


Shooting may provide relief from ground squirrel depredation where very small colonies are under constant shooting pressure. It is, however, an expensive and time-consuming practice. Hunting licenses may be required in some states.

Other Methods

Gas exploding devices for controlling burrowing rodents have not proven to be effective. Propane/oxygen mixtures injected for 45 seconds and then ignited only reduced the population by about 40%. Vacuum devices that suck rodents out of their burrows are currently being developed and tested. No reliable data, however, exist at this time to confirm or deny their efficacy.

Economics of Damage and Control

Very little is known about the economic consequences of ground squirrels foraging in agriculture. A single pair and their offspring can remove about 1/4 acre (0.1 ha) of wheat or alfalfa during one season. Water lost from one canal can flood thousands of acres or cause irrigation failures. The crop loss and cost of repair can be very expensive. Prevention, by incorporating a rodent management plan into the total operation of an enterprise, far outweighs the cost of added management practices.


Figure 1 from Schwartz and Schwartz (1981).

Figures 2 and 3 adapted from Burt and Grossenheider (1976) by David Thornhill. Some of the material included in this draft was written by C. Ray Record in the 1983 edition of Prevention and Control of Wildlife Damage.

For Additional Information

Albert, S. W., and C.R. Record. 1982. Efficacy and cost of four rodenticides for controlling Columbian ground squirrel in western Montana. Great Plains Wildl. Damage Control Workshop. 5:218-230. Andelt, W. F., and T. M. Race. 1991. Managing Wyoming (Richardson’s) ground squirrels in Colorado. Coop. Ext. Bull. 6.505, Colorado State Univ. 3 pp. Askham, L. R. 1985. Effectiveness of two anticoagulant rodenticides (chlorophacinone and bromadiolone) for Columbian ground squirrel (Spermophiluscolumbianus) control in eastern Washington. Crop Protect. 4(3):365-371. Askham, L. R. 1990. Effect of artificial perches and nests in attracting raptors to orchards. Proc. Vertebr. Pest. Conf. 14:144-148.Askham, L. R., and R. M. Poché. 1992. Biodeterioration of cholorphacinone in voles, hawks and an owl. Mammallia 56(1):145-150. Burt, W. H., and R. P. Grossenheider. 1976. A field guide to the mammals, 3d ed. Houghton Mifflin Co., Boston. 289 pp. Edge, W. D., and S. L. Olson-Edge. 1990. A comparison of three traps for removal of Columbian ground squirrels. Proc. Vertebr. Pest Conf. 14:104-106. Fagerstone, K. A. 1988. The annual cycle of Wyoming ground squirrels in Colorado. J. Mamm. 69:678-687. Lewis, S. R., and J. M. O’Brien. 1990. Survey of rodent and rabbit damage to alfalfa hay in Nevada. Proc. Vertebr. Pest Conf. 14:116-119. Matschke, G. H., and K. A. Fagerstone. 1982. Population reduction of Richardson’s ground squirrels with zinc phosphide. J. Wildl. Manage. 46:671-677.Matschke, G. H., M. P. Marsh, and D. L. Otis. Efficacy of zinc phosphide broadcast baiting for controlling Richardson’s ground squirrels on rangeland. J. Range. Manage. 36:504-506. Pfeifer, S. 1980. Aerial predation of Wyoming ground squirrels. J. Mamm. 61:371-372. Schmutz, J. K., and D. J. Hungle. 1989. Populations of ferruginous and Swainson’s hawks increase in synchrony with ground squirrels. Can. J. Zool. 67:2596-2601. Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri, rev. ed. Univ. Missouri Press, Columbia. 356 pp. Sullins, M., and D. Sullivan. 1992. Observations of a gas exploding device for controlling burrowing rodents. Proc. Vertebr. Pest Conf. 15:308-311. Tomich, P. Q. 1992. Ground squirrels. Pages 192-208 in J. A. Chapman and G. A. Feldhamer. eds. Wild mammals of North America. The Johns Hopkins Univ. Press., Baltimore, Maryland. Wobeser, G. A., and F. A. Weighton. 1979. A simple burrow entrance live trap for ground squirrels. J. Wildl. Manage. 43:571-572.


Scott E. Hygnstrom

Robert M. Timm

Gary E. Larson

Proper Watering

Printable version of Proper Watering (PDF)

Proper watering is critical to the success of your plants.

Too much water can be as harmful to your plants as not enough. Many people don’t realize that roots of plants require oxygen. In between soil particles are tiny openings or spaces. In an ideal situation, these gaps should be filled with water and then alternately filled with air. If the spaces are filled with water all the time, there is no oxygen getting to the roots. If there is air between the spaces all the time, there is no water getting into the roots. The oxygen is needed to create the energy the plant uses to take up the water. It is easy to think that because a plant wilts, it needs more water. This is not always the case. If a plant is continually wet, the lack of oxygen to the roots will prevent the plant from using the water available. The roots begin to rot and the plant dies.

This is seen most often with houseplants in the winter when days are short and the weather is overcast. A houseplant can easily go 1 -2 weeks between watering during a NW Montana winter. The plant is essentially dormant.

In the spring, newly planted urns, window boxes and buckets of flowers often have a good deal of extra soil. This soil will hold surplus water. This means that your flowers or vegetables may only need watering every few days. By mid-summer, when the roots have filled the container, these same plants may need water twice a day.

There are some tips to helping keep your roots happy and healthy. The best way to see if your plant needs water is to lift the container. Feel the weight of it when it is wet and then when it is dry. Hot weather can also make a plant wilt. Don’t be fooled into thinking it needs more water on the root system. Check it first.

Make sure your plants are always in containers that have a drainage hole in the bottom. When you water, water thoroughly. If it is an outdoor planter, wash the water through with a hose to keep fertilizer salts from building up. Then let the planter dry out. Don’t put just a little bit of water on every day. Don’t have more than two inches of extra soil around the roots of your indoor plants. Too big of a container holds more water than the plant can use. You can get away with extra soil on outdoor planters as long as you are conservative with the water early in the season. During a rainy spring, you may actually want to tent your planters to keep excess water from drowning your plants.

By mid-summer, many planters and container beds need watering at least once a day. Blossom end rot on tomatoes and potato scab are linked to inconsistent watering. If your planters get overly dry while you are away at work during the day in the hot sun, you may want to consider putting a timer on an irrigation system. While I’m talking about watering, don’t water your garden using an overhead sprinkler. Use a drip or soaker hose. Overhead watering spreads disease in the garden, especially mildews and fungus.

Proper watering goes a long way to ensuring a successful relationship with plants. Being overly liberal with water is as detrimental as overly conservative. Eventually, most gardeners will be able to look at their plants and see if they need water by looking at the color of the foliage and/or very slight flagging. Best of luck and keep on growing.

Proper Watering is Critical to the Success of your Plants Part II

There seems to be a good deal of confusion about watering established trees. More times than not, everyone is consciences about watering a newly planted tree. Two to three times a week on average is good the first season. The water needs to get down about 6-9” so the hose must be set to soak the plant for several hours at a slow drip. Once that first season is over, many people feel the tree should be on its own.

Insects and disease will attack stressed trees first. Wood borers, pine beetles, fungus diseases and weevils are common pests of trees that are suffering from a lack of water.

The most common shade trees in the home landscape are not native to our area. Many of the species have been brought here from the east or west coast where humidity is much higher. 90% of the water in a plant is lost through its leaves. With Montana’s low humidity, the rate of transpiration – loss of water through the leaves – is even higher. These non-native trees require supplemental watering in order to stay in peak condition especially birches and spruces. Maples and Ash will ‘flag’ during times of drought. This wilt is a protective process that decreases the leaf’s surface exposure to the sun. It is the tree’s attempt to reduce transpiration. July and August can be extremely dry in the Flathead. I recommend watering full grown trees at least twice a month during the summer. This would translate into each large tree receiving four 6-8 hour soakings minimally.

The feeder roots of trees are not up against the trunk. They are out at the tips of the longest branch. A soaker hose is a great way to saturate the drip zone without wasting water. The soaker should be allowed to drip until it gets into the ground 1-2”. The rate can be measured by using a tuna can. Just see how long it takes to fill the can twice. This will be how long you want to soak your established trees. Two inches of water should soak down to about 9” into the soil. If you are in heavy clay ground, you may only need to water every 2-3 weeks. If you have sandy or gravely soil, you may need to water every week or two. An average is every two weeks.

Be especially concerned with plants that are under landscape fabric or close to sidewalks and asphalt driveways. The rain does not have the same opportunity to penetrate down to the root system. Supplemental watering may be even more important in these situations.

Lawn sprinklers don’t count when considering the requirements of your trees. Your trees should be on a separate irrigation zone. The lawn is set to 1” per week and that amount of water is usually grabbed by the lawn before ever getting deep enough to impact tree roots. Never water trees with overhead sprinklers, use bubblers, drip irrigation or soaker hoses. Water on the foliage spreads disease such as mildews and other fungus.

Be careful of using mulch against your tree to hold moisture. This can create the perfect home for rodents who will girdle the tree. Mulch against the trunk can rot the tree bark and too much mulch can cause a lack of oxygen and suffocate roots. A small layer of much is beneficial but more is not better in this case. The last comment I will make is that fruit trees require a generous amount of water while fruit is maturing. Water increases the size and firmness of the fruit. Make sure, though, to begin withholding water after September 1st. Reducing water will help the tree to begin hardening off and get ready for winter. Too much water late in the season can decrease winter survival. The exception is evergreens. Evergreens lose moisture from their needles all through the winter. Winter desiccation can be decreased by making sure the ground is damp before the first hard freeze.

The spring of 2016 is quite the opposite of 2015. Water may not be an issue this year but you never know what July will bring. The trees are putting on twice as many leaves and if it turns dry all of a sudden, they will be in real trouble.

If you have any questions, feel free to call the office.

Spray Schedule for Apple Trees (WSU)

Printable version of Spray Schedule for Apple Trees-WSU (PDF)


222 N Havana Spokane WA 99202 (509) 477-2181 http://spokane-county.wsu.edu/spokane/eastside/ [email protected]


Do not apply pesticides until a specific insect or disease has been positively identified. Using wrong or unnecessary sprays is a waste of time and money and can pose a hazard to people and the environment. Apply pesticide sprays only at the proper time of tree, bud, or pest development. Sprays applied at the wrong time are also ineffective. And always read and follow label directions of the product you use!

For help in identifying home orchard problems or for more complete information on specific fruit pests or diseases, contact your county’s WSU Extension office. TIME



Delayed dormant stage: when just a little green color is showing in buds.

San Jose scale, aphid eggs, mites, Lecanium scale, leafroller eggs.

Horticultural mineral oil spray

Pre-pink stage: before blossom buds show pink color

Powdery mildew disease

Fungicide labeled for powdery mildew control on fruit trees.


Insecticidal soap as needed.

Pink stage: blossoms show pink color just before they open fully.

Powdery mildew

Fungicide labeled for powdery mildew control on fruit trees.

Apple scab disease

Fungicide labeled for apple scab control on fruit trees.

Petal Fall: when 3/4 of petals have fallen off

Powdery mildew

Fungicide labeled for powdery mildew control on fruit trees.

Apple Scab

Fungicide labeled for apple scab control on fruit trees.

Cover Sprays: covers leaves and fruit

Codling moth: start sprays when codling moths begin to appear in traps or 17-21 days after full bloom

Malathion every 10-14 days.

Spinosad every 10 days.

Kaolin (Surround WP)-Keep foliage and fruit coated. May have to reapply

Every 10 days.


Insecticidal soap as needed


Insecticidal soap as needed

Powdery mildew

Fungicide labeled for fruit trees.


Spray Schedule for Cherry Trees (WSU)
Printable version of Spray Schedule for Cherry Trees-WSU (PDF)


222 N Havana

Spokane WA 99202

(509) 477-2181


[email protected]


Do not apply pesticides until a specific insect or disease has been positively identified. Using wrong or unnecessary sprays is a waste of time and money and can pose a hazard to people and the environment. Apply pesticide sprays only at the proper time of tree, bud, or pest development. Sprays applied at the wrong time are also ineffective. And always read and follow label directions of the product you use! For help in identifying home orchard problems or for more complete information on specific fruit pests or diseases, contact your county’s WSU Extension office. TIME



Dormant stage: late winter when daytime temperatures are above 40 degrees.

Coryneum blight


Copper or lime sulfur sprays

Bacterial canker

Copper fungicide sprays

Delayed dormant stage: when just a little green color is showing in buds.

Scale insects, aphid eggs, mite eggs.

Horticultural mineral oil spray

Coryneum blight, Brown rot

Captan, copper or sulfur fungicides

Bloom time

Brown rot

Captan (no copper fungicides)

Shuck Fall: when flower petals have fallen away from young fruit.

Powdery mildew and aphids

Wettable sulfur (not lime sulfur) or insecticidal soap.

Brown rot


Summer sprays: Also called cover sprays because they cover leaves and fruit

Cherry Fruit Fly

Malathion every 10 days beginning when cherry fruits turn yellowish. (Usually late May). Allow 3 days minimum to harvest.

Spinosad when cherry fruits turn yellowish.

Mites, aphids

Insecticidal soaps as needed


Bt as worms begin to feed but before leaves are tightly rolled.

Brown rot


Postharvest: prior to heavy fall rains

Cherry fruit fly

Remove all cherries or continue with malathion or spinosad as long as any cherries remain on the tree. Fruit flies continue to breed in unpicked fruit.

Bacterial canker

Copper fungicide



Spray Schedule for Peach and Apricot Trees (WSU)
Printable version of Spray Schedule for Peach and Apricot Trees-WSU (PDF)


222 N Havana

Spokane WA 99202

(509) 477-2181


[email protected]


Do not apply pesticides until a specific insect or disease has been positively identified. Using wrong or unnecessary sprays is a waste of time and money and can pose a hazard to people and the environment. Apply pesticide sprays only at the proper time of tree, bud, or pest development. Sprays applied at the wrong time are also ineffective. And always read and follow label directions of the product you use!

For help in identifying home orchard problems or for more complete information on specific fruit pests or diseases, contact your county’s WSU Extension office. TIME



Dormant stage: late winter when daytime temperatures are above 40 degrees.

Peach leaf curl (on peaches only)

Copper or lime sulfur fungicides

Coryneum blight

Copper or lime sulfur (Do not use lime sulfur on apricots)

Delayed dormant stage: when just a little green color is showing in buds.

Scale insects, aphid eggs, mite eggs.

Horticultural oil spray

Prebloom stage: when just a little flower color shows in the bud but before flowers open.

Coryneum blight, Brown rot

Captan, copper or sulfur fungicides (Do not use sulfur on apricots)

Peach twig borer, aphids


Bloom time

Brown rot


Shuck Fall: when flower petals have fallen away from young fruit.

Coryneum blight, Brown rot


Summer sprays: Also called cover sprays because they cover leaves and fruit

Peach twig borer


Mites, aphids

Insecticidal soaps as needed

Brown rot


Postharvest: prior to heavy fall rains

Coryneum blight

Captan or copper

Peach leaf curl on peaches

Copper or lime sulfur in early February


Spray Schedule for Pear Trees (WSU)
Printable version of Spray Schedule for Pear Trees-WSU (PDF)


222 N Havana

Spokane WA 99202

(509) 477-2181


[email protected]


Do not apply pesticides until a specific insect or disease has been positively identified. Using wrong or unnecessary sprays is a waste of time and money and can pose a hazard to PEOPLE and the environment. Apply pesticide sprays only at the proper time of tree, bud, or pest development. Sprays applied at the wrong time are also ineffective. And always read and follow label directions of the product you use!

For help in identifying home orchard problems or for more complete information on specific fruit pests or diseases, contact your county’s WSU Extension office. TIME



Dormant stage: late winter as buds begin to swell in February

Pear psylla

Horticultural mineral oil spray

Delayed dormant stage: when just a little green color is showing in buds.

Pear psylla, aphid eggs, blister mites, scale insects, leafroller eggs.

Horticultural mineral oil spray plus lime sulfur (Do not use lime sulfur on d’Anjou pears.)

Petal Fall: when all petals have fallen off

Codling Moth

Malathion every 10-14 days. Begin about 10 days after all petals have fallen.

Kaolin (Surround WP)-Thorough coverage is important.

Summer sprays: Also called cover sprays because they cover leaves and fruit

Codling moth:

Malathion every 10-14 days until 14 days before harvest.

Kaolin (Surround WP)-Keep foliage and fruit coated.

Pear psylla

Insecticidal soap, Kaolin, or Azadirachtin (neem extract) as needed.


Bt as worms begin to feed but before leaves are tightly rolled.

Aphids, mites

Insecticidal soap as needed


Spray Schedule for Plum and Prune Trees (WSU)
Printable version of Spray Schedule for Plum and Prune Trees (PDF)


222 N Havana

Spokane WA 99202

(509) 477-2181


[email protected]


Do not apply pesticides until a specific insect or disease has been positively identified. Using wrong or unnecessary sprays is a waste of time and money and can pose a hazard to people and the environment. Apply pesticide sprays only at the proper time of tree, bud, or pest development. Sprays applied at the wrong time are also ineffective. And always read and follow label directions of the product you use!

For help in identifying home orchard problems or for more complete information on specific fruit pests or diseases, contact your county’s WSU Extension office. TIME



Delayed dormant stage: when just a little green color is showing in buds.

Scale insects, aphid eggs, mite eggs.

Horticultural oil spray

Prebloom stage: when just a little flower color shows in the bud but before flowers open.

Coryneum blight, Brown rot

Captan, copper or sulfur fungicides (Do not use sulfur on apricots)


Insecticidal soaps

Bloom time

Brown rot


Shuck Fall: when flower petals have fallen away from young fruit.

Coryneum blight, Brown rot


Summer sprays: Also called cover sprays because they cover leaves and fruit

Mites, aphids

Insecticidal soaps as needed

Brown rot


Peach twig borer


Postharvest: prior to heavy fall rains

Coryneum blight

Captan or copper