Mosquitoes

Detection and Management Strategies for Insecticide Resistant Mosquitoes

West Nile virus (WNV) is the most significant mosquito-borne disease in Wyoming, with Culex tarsalis serving as the primary vector statewide. In 2023, Wyoming experienced nearly three times the number of human WNV cases compared to any year in the previous decade, with most cases linked to in-state exposure. During outbreaks like these, adulticide applications become a critical tool for reducing infectious mosquito populations near people.However, adulticides rely on a very limited number of insecticide classes. Repeated use — even at low frequencies — creates strong selection pressure, allowing resistant mosquitoes to survive and pass resistance traits to future generations.

Concerns of Impacts to Weed Biocontrol from Mosquito Abatement

Thank you to Mikenna Smith, Teton County Weed and Pest Entomologist, for her contributions to this article from her recent research presentation. Biocontrol and Mosquito Control: Are They at Odds? As an entomologist working in both biological control (biocontrol) of weeds and mosquito abatement, I often find myself in a unique position to explore how these two practices interact. When researching whether mosquito control affects weed biocontrol agents, I found surprisingly little direct research. However, there’s a lot of literature on how mosquito pesticides affect non-target insects in general. That’s what I’ve used to guide this discussion.

Mosquito Abatement in West Central Wyoming

Wyoming was the first state to grant women the right to vote and hold public office. It is also home to Yellowstone National Park, the first national park in the U.S. With just 590,000 residents, Wyoming remains the least populated state in the country. Its second nickname, “The Cowboy State,” reflects its long-standing ranching history.Much of Wyoming’s landscape is well-suited for livestock production. More than two-thirds of the land is dedicated to grazing, with cattle being the dominant livestock, followed by sheep and hogs to a lesser degree. The state also produces large quantities of hay.While crop production is less common than grazing, Wyoming farms grow sugar beets, dry beans, seed potatoes, and grains such as wheat, barley, oats, and corn.Wyoming is a rural and arid state, with most of its precipitation falling as snow. In the summer months, water stored in rivers becomes vital for irrigating agricultural lands. Of all irrigated land used for agriculture in Wyoming, flood irrigation accounts for over two-thirds of irrigation practices. However, flood irrigation creates ideal breeding conditions for mosquitoes—especially across large acreages that are often adjacent to small communities. Many of these areas lack formal mosquito abatement programs, posing challenges to both public health and agriculture.

Mosquito Control Awareness Week: Valent Biosciences Field Cage Trial Results in Mosquito Insecticide Resistance

West Nile Virus is the major mosquito-borne disease in the state of Wyoming. One element of our District's Integrated Mosquito Management Plan (IMM) is the use of adulticides for the control of adult mosquitoes. Currently, there are limited modes of action available for their use as adulticides. This has resulted in an alarming degree of insecticide resistance in mosquitoes, particularly in vector species such as Culex tarsalis. Explore how abundance of West Nile Virus has exploded in recent years, the results of our field cage trials with Valent Biosciences and evidence of the resistant populations in Teton County, how resistance develops in mosquitoes, the types of resistance, and how our team prevents, detects, and manages resistance once found.

Pesticide Resistance in Mosquitoes

Teton County Weed and Pest District’s Entomologist, Mikenna Smith, together with scientific staff from Valent Biosciences will be conducting a mosquito “field cage trial” this month. Field cage trials are large scale, field experiments where mosquitoes are placed in cages that are strategically placed in the path of a truck mounted ultra-low volume adulticide spray drift. This is the most “real world” experiment that can be conducted to determine if certain pesticides can kill the caged mosquitoes.

Integrated Pest Management Services for Ranchers

The summer season is here, and we have already been hard at work conducting integrated pest and mosquito management! Did you know that our team provides a variety of resources and services to support the community and ranchers in reducing populations of mosquitoes and the risk of mosquito-borne diseases?

Mosquito Springtime Habitats

There’s a lot of snow that will be melting after an epic winter like the one we just had. Some of us didn’t want winter to end. But you know who DID want the snow to stop and melt? Mosquitoes. Although many summertime mosquitoes hatch in flood irrigated fields, we have plenty of springtime mosquito habitat too.

National Mosquito Control Awareness Week (June 19-25, 2022)

Join us for the National Mosquito Control Awareness Week that extends from June 19-25. Without your support and involvement with TCWP, our mosquito efforts would be in vain. Outreach and community involvement from concerned citizens of Teton County are necessary for an effective Integrated Pest Management system.

American History: A Story of Mosquito-Borne Disease

When you think of a deadly animal what comes to mind? Sharks? Rattlesnakes? Crocodiles? These animals may result in some human deaths but they are far from the deadliest creatures out there. So what’s the “big” killer?— you guessed it, mosquitoes.