Notice: High Abundance of Mosquitoes

While mosquitoes are present year-round in Marin and Sonoma counties, vector control technicians are discovering an early emergence and high abundance of several species of mosquitoes this year. This anomaly is being attributed to the extreme drought followed by flooding and warmer weather.

While numerous mosquito species are being detected in high populations, the most common and aggressive species that are causing problems are salt marsh mosquitoes and treehole mosquitoes.

Salt marsh mosquitoes can fly up to 20 miles, are extremely aggressive biters, can emerge as adults by the thousands, and cause extreme discomfort and potential injury to residents (including schools), visitors, livestock, and wildlife.  These mosquitoes are being found in high numbers in large areas such as wetlands and marshes adjacent to schools and subdivisions.

Treehole mosquitoes are aggressive biters and can emerge in high numbers from standing water that has collected in cavities of oaks and bay trees. These mosquitoes are known vectors of dog heartworm.

Due to the abundance of requests for service from the public, coupled with a reduced workforce the response time is 10-14 days. We are doing our best to respond to all requests for service in a timely manner.

Thank you for your understanding and patience. 

About Us

The Marin/Sonoma Mosquito and Vector Control District is committed to protecting the health and welfare of the communities we serve from mosquitoes and vector-borne disease.


The following brochures are available to download in PDF format.

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