Invasive Aedes aegypti mosquito found in several counties across California, including in San Diego County

SAN DIEGO (FOX 5/KUSI) — An invasive mosquito species that can carry dangerous diseases has been identified in several California counties, including San Diego.

Invasive Aedes aegypti mosquitoes, also known as the yellow fever mosquito, typically bite several times and are active during the day. They can transmit Zika, dengue, yellow fever and chikungunya viruses, according to the San Diego Vector Control Program.

Small black mosquitoes have distinctive white stripes on their legs and backs.

The California Department of Health has been monitoring invasive Aedes mosquitoes throughout California for several years, as part of a statewide vector-borne disease surveillance system.

The San Diego Vector Control Program map shows that invasive Aedes mosquitoes have been found in all areas of San Diego County.

Throughout California, the counties below report the presence of invasive Aedes mosquitoes, while only a few counties in the state have found both Aedes aegypti and Aedes albopictus (also known as the tiger mosquito):

According to the California Department of Health, limited local transmission of the dengue virus has occurred in California, usually from mosquitoes biting people who have previously traveled to areas where these viruses are more prevalent.

The California Dengue Infections Update from CDPH reports infections by county so far in 2024 as of April 1:

• Kings County — 1
• Napa-1
• Riverside — 1
• San Francisco — 3
• San Mateo — 1
• St. Cruz — 2
• Sonoma — 1
• Ventura — 2
• Yolo — 1

In other parts of the country, the CDC map shows the Aedes aegypti mosquito throughout the southern half of the United States, with a lower concentration in the southwestern states of Arizona and New Mexico.

Invasive Aedes mosquitoes lay their eggs in small containers filled with water. In warm weather, mosquitoes can go from egg to adult in less than a week.

Tips for protecting your home from Aedes mosquitoes: dispose of or treat any standing water around your property, check door and window screens to make sure they won’t get inside, wear long sleeves and pants and use insect repellent.

To request an inspection or for questions and advice, contact the San Diego Vector Control Program at 858-694-2888 or vector@sdcounty.ca.gov.