Mosquitoes and West Nile virus

Mosquito season in Colorado usually starts emerging in late April or early May and continues transmitting West Nile virus until the first hard frost, which usually is in September along the Front Range. Protect yourself and your family from mosquito bites, especially from dusk (evening) to dawn (morning) when the mosquitoes are more active.

Mosquito reporting

Call Vector Disease Control International (VDCI) at 877-276-4306 or by visiting their website at Vector Disease Control International to report mosquito problems or issues. The City of Lafayette contracts with VDCI to:

  • conduct surveillance of adult mosquito populations
  • help stop the spread of the mosquito-borne diseases such as West Nile virus
  • reduce annoyance levels when they have been surpassed

The goal is to provide the greatest level of control of pest and disease vector mosquito populations while maintaining a balanced use of cultural, biological, and least-toxic chemical procedures that are environmentally compatible and economically feasible.

Protect yourself by following the 4 D's

  1. Use DEET-enhanced insect repellent
  2. DRESS in long sleeves and pants
  3. Avoid the outdoors at DUSK and DAWN 
  4. DRAIN standing water outside your home

Mosquito-proof your home

Mosquitoes need very little standing water to breed, so eliminating standing water sources around your home can help. One small can of water holds as many as 10,000 mosquito larvae. Protect your property from mosquitos by:

  • Draining standing water around your house at least once every week
  • Emptying water from tires, cans, flowerpots, clogged gutters, rain barrels, birdbaths, toys, and puddles
  • Installing or repairing screens on windows and doors

Illustration of a mosquito with the 4 D's of prevention

West Nile virus

In Colorado, most human West Nile virus cases are reported in August and September. Most people infected with West Nile virus don’t have symptoms. About 20% of infected people will have flu-like symptoms, and fewer than 1% develop a serious, potentially deadly illness. People over age 60 and those with certain medical conditions are at greater risk of serious illness. See a health care provider if you develop severe headaches or confusion.

The likelihood of contracting the virus is very low but steps can be taken to even further reduce the risk - and the number of mosquito bites you get this year - by following the 4 D's and mosquito-proofing your home. Learn more about WNV by visiting Boulder County's mosquitoes and WNV webpage.

Additional WNV resources