TCWP’s mosquito program carries gold membership in pesticide environmental stewardship!

Teton County Weed & Pest District’s mosquito program is living up to its mission by providing superior noxious weed and pest control in Teton County, through environmentally sound integrated management practices and education. The District recently was recognized for its membership in the Gold Tier of the EPA’s Pesticide Environmental Stewardship Program (PESP) since 2007. The EPA’s website states the “gold membership is reserved for PESP’s outstanding environmental stewards”. Marta Iwaseczko, Assistant Supervisor, has put in countless hours making the mission a reality by reducing pesticide risk through integrated mosquito management techniques. “This goal is not to be confused with eliminating pesticide use. It is strictly about being more deliberate and mindful in our use of pesticides. The more we know about the target species, the better enabled we are to take advantage of their particular vulnerabilities,” states Iwaseczko.

A prime example of this approach is the program’s focus on the use of Bacillus thuringiensis israelensis (Bti) for controlling mosquito larvae. “This ubiquitous soil bacterium generates proteins that are toxic to a very small subset of flies, including mosquitoes, which have receptors for these toxins in their gut walls. A mosquito larva ingests these proteins, loses gut wall integrity and dies, while most of the other organisms sharing its habitat go unharmed,” she explains.

PESP is a voluntary membership program that promotes the adoption of innovative, alternative pest control practices such as Integrated Pest Management (IPM). PESP originated from the Environmental Protection Agency (EPA) in 1994 and has since partnered with the American Mosquito Control Association (AMCA) to help reach their goal of reducing pesticide risk throughout the Unites States.

To achieve a PESP membership, one must present an integrated pest management program outline, which is reviewed, commented, and voted on by the AMCA committee and then annual reports are submitted to the EPA on activities performed. The outline includes mosquito surveillance to determine if control is needed, removal of mosquito habitats when possible, biological control, larviciding, adulticiding, and education of the membership and general public.

While pesticides remain a very important tool for protecting the public from West Nile Virus and knocking back invasives species that have the ability to infest our native ecosystem, this is one example of how the District is working to reduce pesticide risk in Teton County. For more information on the District’s stewardship efforts visit