August 2016
Welcome to the Teton County Weed and Pest District newsletter! We plan on updating subscribers on useful information pertaining to Mosquitoes and Invasive Species.

Check out our new website!!!

In this edition you will find information regarding:
  • Fall Perennial Treatments
  • TCWP's avian surveillance for West Nile virus
  • 5th Annual GYCC Work Days on the Gros Ventre River 
  • Remember to Feed Weed Free this hunting season
  • Upcoming Events - TCD Invasive Species Cost Share Program, 

    Landowner completed reimbursement forms must be received by Teton County Weed and Pest by October 19th, 2016 (no exceptions).

Fall Perennial Treatments
It has been proven that some weeds respond well to a late-summer to early fall treatment, even if plants have already gone to seed.  Mostly perennial weeds, populations of these species can be greatly reduced by this late season treatment.  In order to maximize the effects, spraying should take place during the first two to three weeks following the first HARD frost.
Perennial plants live for more than two years and cannot successfully be pulled due to their extensive root systems. The visible portion of the plant appears to die off in the fall only to grow back from nutrients stored in their roots in the spring. These weeds primarily reproduce through their root system and seeds. Often, when the stems or roots of this plant are physically disturbed, it can actually stimulate growth and spread. The best time and method to treat this subset of weeds is with herbicide in the spring and early summer when the plant is actively growing or sometimes even better control can be achieved in the fall after the first hard frost. The frost stimulates the perennials to go into hibernation mode taking all of their energy into the root system for the winter. This is the perfect time to treat perennials with herbicide since the downward movement of nutrients will also get the herbicide to where it needs to go to kill off the root system.

If you have any of the weeds below, contact the Teton County Weed and Pest District office 733-8419 for herbicide recommendations.

Dalmatain toadflax
Yellow toadflax
Canada thistle
Oxeye daisy

Leafy spurge

TCWP's avian surveillance for West Nile virus

West Nile virus (WNV) naturally cycles in native bird populations. That means that the virus overwinters in a bird and when a mosquito subsequently feeds upon its blood in the spring the mosquito ingests the virus. The virus then disseminates throughout the mosquito (including its salivary glands) and thus confers the potential for viral transmission during subsequent blood meals, usually, to other birds. 

Different species of birds have variable immunity to the virus. Some (like crows and ravens) succumb quickly to the virus, while others (like finches, sparrows, and robins) are capable of harboring significant levels of viral proliferation without showing symptoms or dying.

Among other WNV surveillance tools, TCWP tests sickly or dead crows, ravens, jays, and magpies. These can help detect focal points or hotspots of virus around the county. If you find one of these species (and can reasonably determine that Sylvester is not the cause of its demise), please contact our office to report its location. If it meets our criteria for testing we will come to retrieve it, test it for WNV and provide you with results of our testing, usually within 24 hrs. Should it not be testable, we will at a minimum, record the location and look for patterns of avian mortality to drive our WNV mosquito trapping efforts. 
5th Annual GYCC Work Days, 2016
The Jackson Hole Weed Management Association (JHWMA) hosted the fifth annual Greater Yellowstone Coordinating Committee's (GYCC) Cooperative Work Days July 19-21, 2016. Over 80 people came from all around the Greater Yellowstone Area (GYA) to team up for invasive weed control on the Gros Ventre River corridor in Grand Teton National Park, the National Elk Refuge, private and state lands.  Organized by Travis Ziehl of Jackson Hole Property Services, Teton County Weed & Pest and Grand Teton National Park, the group targeted spotted knapweed, Dalmatian toadflax and perennial pepperweed, all invasive weeds that compete with native vegetation and adversely impact wildlife habitat.
"This was a great opportunity to team up with partner organizations and highlight the importance of managing invasive species across the GYA", said Jake Jarrett, GYCC Terrestrial Invasive Species Committee Chair.  "Working across jurisdictional boundaries for the betterment of the entire ecosystem is what the JHWMA and the GYCC Terrestrial Invasive Species Committee are all about".
The spotted knapweed population on the Gros Ventre River represents a major risk for new infestations in other portions of the Greater Yellowstone Ecosystem. Elk radio collar and GPS collar data suggest that 90% of elk migration routes from the National Elk Refuge transect the Gros Ventre River corridor (Smith and Robbins 1994, Cole and Ketchum 2011). Studies show that wild and domestic ungulates facilitate the transport of invasive plants species. Given that elk that winter on the Refuge migrate as far as Yellowstone Lake, the risk of transport to remote locations in the GYA is significant.
Utilizing herbicide spot treatment by backpack and mechanical control, crews treated roughly 81.5 acres, surveying/monitoring 765 acres total along the Gros Ventre Corridor including the town of Kelly.
Thank you to the following groups who made the project a success!
Fremont, Lincoln, Natrona, Park, and Teton County Weed and Pest Districts in Wyoming
Bonneville and Teton County Weed Districts in Idaho
Jackson Hole Fire/EMS
Boreal Property Management
Intermountain Aquatics
Jackson Hole Property Services
Hanna Outfitting
 Bridger-Teton, Custer Galatian, and Shoshone National Forests
National Elk Refuge
Yellowstone and Grand Teton National Parks
National Park Service - Northern Rockies Exotic Plant Management Team
Rocky Mountain Elk Foundation
Teton Conservation District
The GYCC was formed to allow representatives from the National Park Service, US Forest Service, the US Fish and Wildlife Service and the Bureau of Land Management to pursue opportunities of mutual cooperation and coordination in the management of core federal lands in the Greater Yellowstone Area.
The GYCC Terrestrial Invasive Species Committee includes invasive species coordinators from each GYA unit, county weed and pest staff, BLM and other state, county and federal weed managers who work together on the creation of common inventories, establishment of cooperative weed management areas, promotion of best management practices, and development of education and information materials and integrated management plans to manage and prevent the spread of noxious weeds.
To learn more about the GYCC and the various Sub-committees, please visit

Remember to Feed Weed Free this hunting season
Upcoming Events
2016 Summer Office Hours, May 1st - September 30th: Tuesday - Friday
7:30 a.m. - 5:30 p.m.

October 19th, 2016 (no exceptions) - TCD Invasive Species Cost Share ProgramLandowner completed reimbursement forms must be received by Teton County Weed and Pest by October 19th, 2016 (no exceptions).

Visit our Event Calendar on our website for more info. 

Thank you for subscribing to the Teton County Weed and Pest District Newsletter. We hope that you find the information useful! If there are any topics that would be of interest to you, please email me your suggestions. 




Amy Collett
Teton County Weed and Pest District
7575 S. Hwy 89 Jackson, WY 83001