Invasive Aedes Mosquitoes

Aedes aegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito) have been detected in the County of San Diego. These mosquitoes are not native to California and can transmit the viruses that cause Zika, dengue, chikungunya, and yellow fever. There have been no recent cases of these viruses being transmitted locally in California. Aedes notoscriptus (the Australian Backyard Mosquito) has also been detected in the County of San Diego.

All three invasive Aedes mosquitoes are small black mosquitoes with white stripes on the legs and back. They bite aggressively during the day, especially around the legs and ankles. Invasive Aedes mosquitoes lay their eggs in small containers of water and will readily breed in backyards and even inside homes. In warmer months, these mosquitoes can go from egg to adult in less than one week.

Invasive Aedes Mosquito activity in San Diego County

Invasive Aedes mosquito activity for prior years

Prevent Mosquito Breeding

Invasive Aedes mosquitoes are "container breeders" meaning that they prefer to lay their eggs in small containers of water (even 1/4" of water is enough!). Their eggs can even survive for over a year in dry containers, and will hatch when water is added. Aedes mosquitoes do not fly far; their breeding source is likely to be close by - either around your home or on a neighboring property.

To prevent mosquito breeding, check for and dump out standing water inside and outside at least once a week, in places such as buckets, birdbaths, saucers under potted plants, and children's toys. Use our Prevention Checklist as a guide to get started!

Add mosquito fish (available free of charge from the
Vector Control Program) or a mosquito larvicide (available for purchase at home and garden stores, follow all instructions on the label) to water in backyard ponds, fountains, and unfiltered pools.

If collecting rainwater, make sure your rain barrel remains securely screened/sealed to prevent mosquito breeding.

Once you have eliminated mosquito breeding sources in your yard, talk to your neighbors – mosquito control is a shared responsibility.

Protect Yourself Against Bites

Put screens on windows and doors. Screens can prevent Aedes mosquitoes from living and breeding indoors.

Wear long sleeves and pants. They are aggressive biters indoors and outdoors, especially during the day.

Apply insect repellent containing an EPA approved active ingredient such as: DEET, picaridin, oil of lemon eucalyptus, Para-menthane-diol, 2-undecanone, or IR3535. Use insect repellent as directed by the label.

Find the right insect repellent for you and your family (United States Environmental Protection Agency search tool)

Report

Follow the steps above to prevent Aedes mosquito breeding and to protect yourself from bites. Help your immediate neighbors to do the same. To report persistent issues, request an inspection, or for questions and advice – contact the Vector Control Program.

(858) 694-2888
vector@sdcounty.ca.gov