Public Health Madison & Dane County

Mosquitoes

monitoring for mosquitoes

In summer, we watch certain mosquito breeding areas for mosquitoes that carry diseases that can make you sick.

Why Are We Concerned About Mosquitoes?

  • Mosquitoes can spread diseases like West Nile Virus.
  • The main mosquito species we track is the Culex mosquito. This species can cause West Nile Virus infection in humans.

What We Do To Reduce Numbers of Mosquitoes that Cause Disease

  • In addition to watching breeding areas, we trap adult mosquitoes to measure how many are in an area. Some of the mosquitoes are tested for West Nile Virus.
    • If we find high numbers of the species that can spread West Nile Virus, we treat water on public lands to reduce the number of mosquitoes.
  • We do this work in partnership with:
    • City of Madison
    • City of Middleton
    • City of Monona
    • City of Sun Prairie
    • Town of Madison
    • Village of Maple Bluff
    • Village of Shorewood Hills
    • The University of Wisconsin

You can Prevent Mosquito Bites and Disease

Prevent Mosquito Bites

  • Wear long-sleeved shirts and long pants from dusk through dawn. That's when many mosquitoes are most active.
  • Install or fix screens on windows and doors to keep mosquitoes outside.
  • Use EPA-registered insect repellents and follow instructions carefully.
  • Apply permethrin to your clothes and gear or buy items treated with permethrin.

Get Rid of Areas Where Mosquitoes Breed

  • Mosquitoes lay eggs in or near water. Once a week, dump or clear water out of things like:
    • Flower pots
    • Gutters
    • Buckets
    • Pool covers
    • Pet water dishes
    • Birdbaths
    • Rain barrels
    • Trash cans

Where are West Nile mosquitoes found in Dane County? 

The map below shows our summer 2023 larvae monitoring results. Culex mosquitoes (red icons) are most likely to carry West Nile virus. Aedes mosquitoes (yellow icons) can carry West Nile virus, but more rarely. 

Dead Bird Reporting

West Nile virus is spread to humans through the bite of an infected mosquito. Mosquitoes get infected with West Nile virus by feeding on infected birds. Crows and blue jays are known to get sick and die from West Nile virus.

The WI Department of Health Services is no longer testing crows and blue jays for West Nile virus and the Dead Bird Reporting Hotline is now closed. If you find a sick or dead bird, please visit the Wisconsin Department of Natural Resources (DNR) Wildlife Health Program website. It gives information about which birds to report.

Most dead birds do not need to be reported or collected, and can be thrown away. Don’t handle dead birds with bare hands. To safely dispose of a dead bird:

  • Use gloves or an inverted plastic bag to put the carcass in a garbage bag
  • Put the garbage bag in the regular trash
  • Wash your hands with soap and water for at least 20 seconds

Resources

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