Laramie updates mosquito hotline, sunset spraying planned for July 1

Laramie set a sunset mosquito treatment for the South Route on July 1, using Zenivex E4 RTU as the city kept its hotline moving for anyone planning to be outside around town. The update matters for evening walkers, park users, outdoor businesses and holiday-week events because the city times its fogging for dusk and can change the route as conditions shift.

The city updates its mosquito and chemical-application hotline daily at about 4:30 p.m., and residents can call 307-721-5056 for the latest route and application information. City materials say suspended routes may be resumed the following evening if the work is not finished, which makes the schedule a live service notice rather than a fixed calendar. Laramie says its adult mosquito control uses ULV, truck-mounted foggers and rotates through three zones: West, North and South.

Zenivex E4 RTU is the product listed for the July 1 application. City materials say it contains 4% etofenprox and is used for adult mosquito control by authorized applicators. The city’s no-spray program also lets property owners request exclusion from fogging, and reflective boundary markers can be placed to identify property lines before applications.

The public-health backdrop is still active even with a low-risk label. Laramie says its West Nile virus risk remains Level 1, or low risk, because it has tested zero mosquito pools positive so far in 2026. In plain terms, that means the city has not found West Nile in its local mosquito samples this season, but it is still treating standing water, monitoring wetland and irrigated areas, and fogging where conditions call for it. The city says larvicide is applied in irrigated and wetland areas in and around Laramie throughout the spring and summer, while adult-control work is scheduled separately.

The concern is not abstract. Laramie identifies Culex tarsalis as the known regional vector for West Nile virus, and the Wyoming Department of Health says the virus has been detected in every county in the state. In September 2025, state health officials said Wyoming had 11 human cases, including six severe cases and one death. That history helps explain why the city keeps issuing route-by-route updates even when the current local risk level is low.