• Contact FCWP

  • Lander Office 307-332-1052
  • Lander Shop 307-332-3709
  • Riverton Office and Shop 307-856-2192
  • Dubois 307-240-0710
  • fcwp@wyoming.com

Mosquito (Culex tarsalis)

Culex tarsalis is one of the species of mosquito that can carry and transmit West Nile virus. Because this species occurs in certain areas of Fremont County it is a County Declared Pest.

Fremont County Weed and Pest partners with the cities and towns within Fremont County, Northern Arapahoe Tribal Health, and Eastern Shoshone Tribal Health to monitor mosquito populations from June to September, trapping thousands of mosquitoes and testing them for West Nile virus.

Culex I.D.

West Nile virus is a mosquito-borne disease that can cause a potentially serious illness in humans and horses. It can even be fatal. The number of human illnesses from West Nile virus in Fremont County fluctuates from year to year and the severity of symptoms varies greatly. 

Fogging for mosquitoes and larvacide treatment is conducted by the cities and towns within Fremont County,  Northern Arapahoe Tribal Health, and Eastern Shoshone Tribal Health . Funding for the mosquito control programs is provided by a Wyoming Department of Agriculture grant, participating municipalities and FCWP, which administers the grant.

FCWP sells larvicide and other mosquito controls. Many other good products are available in local home and hardware stores.

From the Wyoming Department of Health -

Although mosquitoes are most active at dusk or dawn, some bite during the day. Mosquitoes will bite if you enter an area where they are resting, such as high grass or heavy underbrush. While it is not necessary to limit outdoor activity (unless there is evidence of mosquito-borne disease in the area), you can and should reduce your risk of being bitten by mosquitoes.

Common sense steps you can take to minimize the probability of infection include remembering the

5 Ds of West Nile Virus prevention:
1. DAWN &

DUSK When possible, avoid spending time outside at dawn and dusk.

DRESS Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time or when mosquitoes are most active. Clothing should be light colored and made of tightly woven materials to keep mosquitoes away from the skin.

DRAIN Reduce the amount of standing water in or near your property by draining and/or removing it. Mosquitoes may lay eggs in areas with standing water.

DEET For additional protection from mosquitoes, use an insect repellent containing DEET (N,N-diethyl-m-toluamide) or picaridin (KBR 3023). Other insect repellents such as oil of lemon eucalyptus and IR3535 are also registered by the EPA but may be less effective than products containing DEET. It is important to follow the product guidelines when using insect repellent.

Here are some other tips from the CDC and WY Dept of Health:


BACK to Pests page

Statewide info

Click here to view the website that contains the Wyoming West Nile Virus Surveillance Summaries  from the Wyoming Department of Health.

About Zika

The two species of mosquitoes that can carry and transmit Zika virus, Aedes aegypti and Aedes albopictus, have never been detected in Wyoming so it is highly unlikely someone would contract Zika virus from a mosquito bite in our state.