Mosquitoes in Laramie County Test Positive; West Nile Virus Carriers

The City of Cheyenne has detected an increase in Culex mosquitoes across the city and the county. Culex mosquitoes are the primary vector of West Nile Virus in our region. Heavy rains combined with rising temperatures will likely lead to increasing numbers of these mosquitoes in the coming weeks.

The City of Cheyenne’s Weed and Pest Division will continually inspect known larval habitats and begin Ultra Low Volume (ULV) truck spraying for adult mosquitoes in areas with high numbers of Culex. These trucks will pass through neighborhoods and recreational areas after sunset. You may see a strobe light and hear a small equipment motor as they pass, but there is no reason to be alarmed.

More information on ULV truck spraying can be found at:

Most mosquitoes do not test positive for disease-causing viruses. However, a bite from a West Nile Virus-infected mosquito can cause severe illness and, in some cases, death. Although a person’s chances of getting sick are small, those aged 50 and older are at the highest risk for serious illness. Not everyone infected with West Nile Virus will become ill.

However, West Nile can cause serious complications, including neurological diseases, and can also cause a milder flu-like illness, including fever, headache, body aches, nausea, and occasionally a skin rash and swollen lymph glands. If you think you have symptoms of West Nile Virus, please see your doctor right away.

Mosquitoes lay their eggs in standing water. The eggs hatch into larvae that develop in the water from seven to 10 days before emerging as adult mosquitoes that fly and bite. Many types of mosquitoes, including those that can spread disease, lay their eggs in items around the home, such as in birdbaths, unused flowerpots, discarded tires, and even bottle caps, as well as in small ponds or other bodies of stagnant water.

The professionals with Cheyenne Weed and Pest and the Cheyenne-Laramie County Health Department’s Mosquito Control Program are doing the utmost to protect us all. We ask that you do your part in checking your property to eliminate any standing water where mosquitos could breed.

The best and most effective mosquito control begins in your yard. Eliminating standing water is the first step in reducing mosquito breeding, as well as:

  • Checking your property for ANY items that can hold water. Anything you choose to keep outside, such as kids’ toys, buckets, wading pools, canoes, and wheelbarrows, should be flipped over when not used to prevent them from collecting any water.
  • Drill holes in recycling container bottoms and remove discarded tires.
  • If you have a swimming pool or spa not in use, drain the water off the cover or treat the standing water with Mosquito briquettes and post accordingly. The briquettes are available from the Health Department at 100 Central Ave., Monday through Friday, while supplies last. Call (307) 633-4090 or e-mail to arrange a pickup.
  • Tightly cover water storage containers (buckets, cisterns, rain barrels) so mosquitoes cannot get inside to lay eggs. Use wire mesh with holes smaller than an adult mosquito for containers without lids.
  • If you have a septic tank, repair cracks or gaps. Cover open vents or plumbing pipes. Use wire mesh with holes smaller than an adult mosquito.
  • Make sure that roof gutters drain properly, clear vegetation and debris from the edges of ponds, and remove leaf debris from yards and gardens.

Also, to reduce your risk of being bitten, use the following 5-D methods:

  • DUSK & DAWN – Stay indoors when mosquitoes are more active.
  • DRESS – Cover-up as completely as possible. Wear shoes and socks, long pants, and a long-sleeved shirt when outdoors for long periods or when mosquitoes are more active.
  • 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 – Use mosquito repellent, which should always be applied according to label directions. Do not use repellent on babies younger than 2-month-old. Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children younger than 3-years-old.

To learn more, call the Health Department at (307) 633-4090 or visit the West Nile page at: