If you believe you have seen invasive Aedes mosquitoes in San Mateo County, please call (650) 344-8592 or make a service request for insect identification.

Aedes aegypti (Yellow Fever Mosquito)

Native to Africa, but found in many tropical and subtropical regions worldwide. Bites humans during the day. Capable of transmitting yellow fever, dengue fever, and chickunguna viruses (the risk of these viruses is low in San Mateo County).

In 2013, Aedes aegypti was found in San Mateo County for the first time since being eradicated in 1979.  Through an intensive program, District staff eradicated the species in 2015.

For more information about Aedes aegypti in San Mateo County, visit our Aedes aegypti information page.