Heads Up, Williston! Mosquito Spraying Starts June 6

Williams County Vector Control Adulticide Treatments

As the temps rise, so does mosquito activity. The Williams County Vector Control District will be conducting truck mounted adulticide treatments between June 6–9, 2025 in Williston (Spray Block 8).

Treatment Schedule and Location

Weather and conditions permitting, treatments will occur near sunset. Find this information and a map of the WVCD Spray Blocks here.

Safety Notice

Please maintain a distance of at least 300 feet behind Vector Control trucks when they are fogging, and keep your pets indoors.

About the Adulticide Used

The WCVCD uses Zenivex E20 for adult mosquito control treatments (adulticides), which contains the active ingredient Etofenprox. Zenivex E20 is approved for use in residential areas by the Environmental Protection Agency (EPA).

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Preventing Mosquito Bites

To avoid mosquito bites, residents are advised to take extra precautions during dusk to dawn in the summer months:

• Wear long sleeve, tight-knit shirts and long pants 

• Limit time outdoors during these hours 

• Use mosquito repellents such as DEET, Picaridin, or oil of lemon eucalyptus 

• Prevent mosquito re-population by eliminating standing water on your property. 

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Dates of mosquito control treatments are subject to change and are based on multiple factors including weather and mosquito abundance. For more details, visit: www.williamsnd.com/department/vector-control

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