Aedes aegypti FAQs
Aedes aegypti, also known as the yellow fever mosquito, is an invasive species native to Africa and very difficult to control once established. In California, it was first discovered in 2013 in Fresno, Madera, and San Mateo counties. Aedes aegypti is now found in at least 28 counties statewide, including nearby counties.
Aedes aegypti mosquitoes can transmit diseases, such as dengue, Zika, chikungunya and yellow fever. If Aedes aegypti becomes established in Alameda County, it could threaten public health and quality of life, as these mosquitoes are highly aggressive and active during daylight hours.
Learn more about Aedes aegypti in Alameda County:
The Alameda County Mosquito Abatement District performs year-round mosquito surveillance and control activities throughout Alameda County.
As of November 2025, the District has found numerous adults and larval Aedes aegypti mosquitoes in Livermore, Pleasanton, Fremont and Dublin. Residents can expect to see District staff conduct:
- Surveillance trapping (mosquito monitoring traps),
- Mosquito control and/or
- Door-to-door inspections where we check for standing water sources
Mosquitoes need water for their life cycle. They lay eggs near water and swim in water for their larval stage and pupa stage. Without standing water, mosquito eggs will not hatch, this is why we inspect for standing water.
Door-to-door inspections consist of staff looking for any mosquito eggs, larvae, or pupa in standing water that can serve as a mosquito breeding habitat. Aedes aegypti mosquitoes are “container” breeders, meaning that female adults lay their eggs on the sides of containers like buckets, pot saucers, lawn drains, and other artificial containers and yard clutter that can hold a bottlecap or more of water.
These eggs can survive 6 or more months through the winter after being laid and hatch into larvae once re-introduced to water. Staff can also provide treatment (free of charge) for any standing water sources that cannot be covered or drained.
Staff will always wear their District uniform with official logos and identification and use District vehicles with the official logo.
KRON 4 did a segment on a detection in Livermore and provides examples of what residents can expect to see during an inspection.
KRON 4 news segment from August 12, 2025.
At-Home Mosquito Prevention Steps:
- Use our checklist to inspect for standing water around your home and backyard on a weekly basis and look for mosquito larvae and pupae.
- Dump and scrub containers using a strong brush and dish soap or 5% bleach solution to destroy eggs.
- Use window screen mesh or a finer mesh material to cover lawn drains (including French drains) and rain barrels so female mosquitoes cannot lay their eggs there.
Protect Yourself from Mosquito Bites:
- Apply insect repellents containing EPA-registered ingredients such as DEET, picaridin, IR3535, or oil of lemon eucalyptus.
- Wear long-sleeved shirts, pants, socks, and shoes when mosquitoes are most active.
- Ensure window and door screens are in good condition.
- Report aggressive daytime mosquito biting to the Alameda County Mosquito Abatement District by calling us at (510) 783-7744 or submitting a Service Request online.
If you develop a fever, headache, and joint or muscle pain after returning from an area where dengue, chikungunya, yellow fever, or Zika is present, contact your doctor. Use mosquito repellent for three weeks and stay indoors as much as possible to avoid mosquito bites and prevent the possible spread of disease.