Mosquito & Chemical Application Hotline (307) 721-5056

Updated September 6th, 2023 @ 4:00pm  (Final update for the day will be done by 4:15 pm.)


West Nile Virus Risk: Level 1 (Low Risk)

Adult Mosquito Fogging: All fogging's are weather dependent as required by label and department procedures. If wind speeds exceed 10mph, temperatures drop below 50 degrees, or it is raining fogging routes will be suspended for the evening. Weather will be assessed at an hour before sunset, +/- 30 mins, to determine if routes will be suspended. If these condition arise during an active route the rest of the remaining route will be suspended. Suspended routes will resume the following evening. See Tentative Fogging Calendar Below Updated 8/29/23


Date & Time:

Chemical: Zenivex E4 RTU 

Center for Disease Control (CDC) : What You Need to Know About Truck Spraying

West Nile virus (WNV) Surveillance Update: So far in 2023, two hundred sixty-two (262) mosquito pools have been tested with twenty-five (25) testing positive for West Nile virus. Positive mosquitoes were collected from rural areas outside city limits.

In 2022, forty-one (41)  mosquito pools were tested with one (1) mosquito pool testing positive for West Nile virus. 

In 2021, one hundred and twelve (112) mosquito pools had been tested. Four (4) mosquito pools had tested positive for West Nile virus during the 2021 season. 

Larval Mosquito Control: 

Mosquito Control will be applying larvicide to control larval mosquitoes in irrigated and wetland areas in and around Laramie on a daily basis throughout the spring and summer seasons.

Larvicides include: 

  • Bacillus thuringensis israelensis (Bti)- is a bacteria used as a biological control agent for the larval stage of certain dipterans such as mosquitos, fungus gnats, and blackflies.
  • Methoprene- is an insect juvenile hormone analog which is a growth regulator.
  • BVA 2 Mosquito Larvicide Oil- When applied evenly over the water surface it rapidly interrupts the air/water interface and suffocates larvae and pupae
    • Used only in areas where Vector and Nuisance mosquito populations pose a public threat and are outside of the control window of Bti


Noxious Weeds: 






Bare Ground:



Applications will begin at 5:00AM Weather/Time permitting 

All applications are on a weather permitting basis.

How to use Map Legend for City of Laramie Fogging Zones

  1. Click the Square located at the upper left side of the map below
  2. Check mark the areas you wish to see and uncheck mark the areas you don't want to see
  3. To see the Perimeter zones better uncheck the Zone in that area


-----------------------------------------------------------------------------------------Hotline information regarding chemical applications on city owned properties will be updated daily at 4:00 PM. Call 721-5056 or click on the Mosquito and Chemical Application Hotline tab on the City of Laramie home page. 

All applications are on a weather permitting basis.