While mosquitoes are present year-round in Marin and Sonoma counties, we are seeing and abundance of adult treehole and salt marsh mosquitoes this spring in certain areas of Marin and Sonoma counties.  These particular mosquitoes are extremely aggressive in their biting behavior.

Salt marsh mosquitoes can fly up to 20 miles from the source, 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.