Mosquito spraying to combat West Nile virus in Fort Collins

Samantha Ye

Facing a high level of West Nile virus infected mosquitoes, the City of Fort Collins will spray for mosquitoes in central and north Fort Collins Sept. 8 and Sept. 11, weather permitting.

Spraying will begin at 8 p.m. and end by 2 a.m. each night. 


According to a City news release, spraying will take place in the areas generally between:

  • Douglas Road, Shields Street, Vine Drive and Timberline Road
  • Vine Drive, College Avenue, Drake Road and Timberline Road
  • Laurel Street/Elizabeth Street, Overland Trail, Drake Road and College Avenue

The area encompasses Colorado State University, and the Larimer County Department of Health and Environment will also spray for mosquitoes in adjacent Larimer County areas.

The City has provided a map showing the area that will be sprayed completely both nights.

To minimize pesticide exposure, the City recommends residents and pets stay indoors and that doors and windows remain closed for 30 to 60 minutes after spraying.

Residents can further minimize exposure by covering organic gardens, ponds and water features with a sheet or tarp.

Residents can monitor the spraying trucks’ progress through an online GPS tracking feature. Vector Disease Control International, the City’s spraying contractor, will use a permethrin-based product that will be applied in a fine mist. 

The spraying was triggered following a recommendation by the LCDHE, according to the release. 

According to the City website, the northeastern quadrant of Fort Collins has a high vector index of 0.7, as of Sept. 3. This means approximately 70% of mosquitoes trapped per night there are infected with WNV.

In Larimer County, the first human WNV case was detected in late August

Samantha Ye can be reached at or on Twitter @samxye4.