Skip to main content

Mosquito look-a-likes out in force.

During this time of year, the District receives numerous calls from the public regarding large swarms of mosquitoes in backyards and along bike trails. Fortunately, these swarms of insects are not mosquitoes, but non-biting midges.

To the untrained eye, one could easily mistake these insects for mosquitoes because of their size and the mistaken belief that mosquitoes swarm. While midges do not pose a health threat, they can be quite bothersome, particularly in communities adjacent to large aquatic habitats.

Any person that has had the pleasure of a mouth full of these insects while out walking, running or biking can attest to what a nuisance they can be when in large congregations.

At peak emergence, midges have been known to cover the sides of homes, cars, and other structures. These insects can also be found in large clusters in breezeways, near front doors, and over vegetation. Homes and buildings with outside lighting tend to attract large numbers of these insects.

The good news is that midges are short lived and do not bite. Here are few ways to help discourage them from making your front door the new local hangout:

  • Move lights away from areas such as doorways, windows, patios, etc.
  • Avoid using electronic bug zappers. The light in the bug zapper is an attractant and tends to kill many insects that are beneficial predators.
  • Replace mercury vapor lights with yellow or sodium vapor lights.

The District does not control non-biting insects. If you do find that you are being bitten, contact the District at 707-285-2200. It is possible that there may be standing water that is producing mosquitoes in your area.

Learn more about the most common insects that resemble mosquitoes in Marin and Sonoma counties: https://www.msmosquito.org/insects-that-resemble-mosquitoes

Join our mailing list