Southern California

It's Mosquito Season. Here's All You Need to Know

The aggressive bloodsuckers, which appear more often as the summer months heat up, have colonized in Southern California over the last few years

NBC Universal, Inc.

What to Know

  • Aedes mosquitoes arrived in SoCal several years ago
  • They will aggressively bite multiple times in one sitting, and will come out in the middle of the day -- atypical SoCal mosquito behavior
  • While native mosquitoes need a large body of water, like a pool, to breed, these can breed in a small bottle-cap of water, and eggs can last up to a year

It's that time of year again: it's time for swimming, basking in the sun, and of course, fending off annoying bites from mosquitoes. 

What's worse, in Southern California, is the presence of an aggressive ankle-biter mosquito that will bite multiple times, and doesn't wait for dusk — they'll attack right in the middle of the day, or even inside your house. That's atypical mosquito behavior, at least for the kinds that are native to Southern California. 

If you've noticed over the last few years that you've been bitten multiple times around your ankles, you were likely victim to the Aedes mosquito, which officials believe arrived on a container ship from Asia. It's an invasive species, meaning not native to Southern California. And they have the potential to carry harmful diseases, including the Zika virus. 

What do Aedes mosquitoes look like?

Aedes aegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito) are small black winged creatures with white stripes on their backs and legs, LA County Vector Control said. You may also notice what looks like a long striped tail.

AFP/Getty Images
An Aedes Aegypti mosquito is photographed on human skin in a lab of the International Training and Medical Research Training Center (CIDEIM) on January 25, 2016, in Cali, Colombia. CIDEIM scientists are studying the genetics and biology of Aedes Aegypti mosquito which transmits the Zika, Chikungunya, Dengue and Yellow Fever viruses, to control their reproduction and resistance to insecticides. The Zika virus, a mosquito-borne disease suspected of causing serious birth defects, is expected to spread to all countries in the Americas except Canada and Chile, the World Health Organization said.
Jack Leonard/New Orleans Mosquito and Termite Control Board/Getty Images
An Asian Tiger mosquito feeds from the blood from a person in an undated photo. Officials are warning about a rare mosquito invading the West Coast that has been known to carry Dengue fever and other diseases abroad. Health officials say that the bugs are coming from Asia in shipments of popular bamboo plants.

Where are they found in California?

The relentless Aedes mosquito has been spotted in a host of places — Los Angeles, Orange, Riverside, San Bernardino, San Diego, Tulare, Merced and even more counties, according to the California Department of Public Health. 

The presence of Aedes mosquitoes in Southern California reported in different counties as of April 2021.

See the full list here.

Fast Facts

Not all mosquitoes bite. Female mosquitoes feed on your blood because they need it for their eggs. Male mosquitoes feed on flower nectar. 

Dogs can also get mosquito bites. When they do, they sometimes can contract heartworms, which can be fatal. 

Aedes mosquitoes have the potential to transmit dangerous diseases like dengue, chikungunya, Zika, and yellow fever, however, none of these viruses have been transmitted in California via ankle-biter mosquitoes. 

"Native mosquitoes bite at night. These bite in the daytime. While native mosquitoes need a large body of water, these can breed in a small bottle-cap of water," Robert Saviskas, the executive director of LA County West Vector Control told NBCLA in a previous report.

They also lay larva just below the water line.

"Those eggs can last up to a year … and still be viable," Saviskas said. 

Residents see more mosquitoes as the summer months heat up, with the height of service requests for experts to check peoples' homes in August and September, at least in the greater Los Angeles County vector district. The reason for that also comes from people watering their lawns more frequently in the summer, creating even more water sources for mosquitoes to lay eggs. 

Mosquitoes also don't like to travel too far from the standing water source, so if you've got mosquitoes, it's either in your yard, or a neighbors. 

Do you have a gorgeous, colorful bromeliad plant? You might want to reconsider. Because of how the water pools on those plants, mosquitoes love them, according to Greater LA County Vector District's Public Information Officer Anais Medina Diaz. 

Joe Raedle/Getty Images
Pooled water where mosquitos are breeding is seen on a bromeliad plant as Miami-Dade county mosquito patrol continues to be proactive in fighting a possible Zika virus outbreak on April 20, 2016, in Miami Gardens, Florida.

Curious about which animal and insects are natural predators to mosquitoes, such as dragonflies? Read more here. 

How to help avoid breeding mosquitoes

Get rid of standing water — at any amount. A mosquito can breed in as little as a capful of water, and can complete their life cycle in a week. 

They can breed indoors and outdoors, so make sure you don't have any containers filled with water just sitting around in your house. 

Where they can breed: Buckets, plant saucers, old tires, fountains, swimming pools — even your recyclables. Also, don't forget about ground drain boxes. 

Buy and use insect repellent

Look for insect repellent with the following ingredients.

  • DEET
  • Picaridin
  • Oil of Lemon Eucalyptus
  • IR3535

Vector Control in your area

Los Angeles

If you've done all you can do and you are still seeing mosquitoes, you can fill out the service request form or call 562-944-9656.

There is a wonderful and natural solution to pesky mosquitoes as well — mosquito fish! A large female mosquito fish can eat up to 100 mosquito larvae per day. They can survive in water temperatures 33 to 104 degrees. 

They're best for pools, birdbaths, fountains, and water troughs that are not regularly maintained. You can learn more about them here

Get your mosquito fish by calling District Headquarters at 562-944-9656 or the Sylmar Branch at 818-364-9589. You can also request them online here

It's important to note: It is against California Department of Fish and Game regulations for private citizens to plant mosquito fish in waters of the state without a permit, so place them on your property only. 

Orange County

If you live in Orange County and have a mosquito problem that hasn't been solved by taking the above tips, fill out the form on the vector control's website here.

Read more here. 

Another option is to use mosquito fish (on your property only) to rid water of larvae. Find out how Orange County residents can get them delivered here.

San Bernardino

San Bernardino residents can also get mosquito fish from the county. One request may be made per house per year. 

Get information about programs at the county's vector control site here.

Neglected pools can also create a mosquito habitat. If you have a concern about someone's pool, you can call 1-800-44-ABATE (1-800-442-2283).

Sometimes birds can get bitten by a mosquito and contract West Nile virus. To report a dead bird that died within the last 24 hours, call the California West Nile virus hotline at 1-877-WNV-BIRD (1-877-968-2473).


If you need help with a mosquito problem, fill out the service form here. Residents can call the office for more information at 951-340-9792. 

You can also learn about city-specific programs throughout the county here.


Contact the Ventura County Vector Control at this number for help with mosquitoes: 805-654-2494.

Santa Barbara

Call Mosquito and Vector Management District of Santa Barbara County for help at 805-969-5050, or fill out an online form here.

Contact Us