Updated February 27, 2026 @ 4:30 pm (Final update for the day will be done by 4:30 pm.)

MOSQUITO CONTROL

Use the following links to learn more about our Integrated Mosquito Management Program  

West Nile Virus Risk: Level 1 (Low Risk)

Adult Mosquito Fogging: All fogging is 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, even if in progress. Weather will be assessed an hour before sunset, +/- 30 mins, to determine if routes will be suspended. If these conditions arise during an active route, the remaining route will be suspended. Suspended routes may be resumed the following evening depending on the amount accomplished. 

See Tentative Fogging Calendar Below, Updated 7/30/25

Location: With low numbers of vector and nuisance mosquitoes across all traps, fogging operations have been suspended as long as numbers remain low.

Date & Time: 

Chemical: Zenivex E4 RTU 

Adult Aerial 

Location: Southwest of the city limits along Highway 230 and the Big Laramie River drainage from the City limits southwest approximately 10 miles; West of the city limit between the Big Laramie River on the South, Interstate 80 on the north and the Laramie Regional Airport on the west; the third area is north of the city limit between Welsh lane and 45th street including the area of the city wastewater treatment plant and the city landfill. 

Date & Time:

Chemical: Dibrom, applied at the ultra-low-volume rate of 1/2 ounce per acre. 

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

West Nile virus (WNV) Surveillance Update: So far In 2026, mosquito control tested Zero (0) Culex tarsalis pools, with Zero (0) mosquito pools testing positive for West Nile virus using the RAMP platform.

• 2025- 146 Culex tarsalis pools were tested, with 30 samples positive for West Nile
• 2024- 23 Culex tarsalis pools were tested, with 9 samples positive for West Nile
• 2023- 262 Culex tarsalis pools were tested, with 25 samples positive for West Nile
• 2022- 41 Culex tarsalis pools were tested, with 1 sample positive for West Nile
• 2021- 117 Culex tarsalis pools were tested, with 4 samples positive for West Nile

Larval Mosquito Control: 

Mosquito Control will apply larvicide to control larval mosquitoes in irrigated and wetland areas in and around Laramie daily throughout the spring and summer.

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 black flies.
• 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 threat and are outside the control window of Bti.

IPM (INTEGRATED PEST MANAGEMENT)

Noxious Weeds: 

Location:

Chemical:

Broadleaf: 

Location:

Chemical:

Bare Ground:

Location:

Chemical:

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

All applications are on a weather-permitting basis.

How to use Map Legend for the 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.