HAYWARD, Calif. October 6, 2026 — The Alameda County Mosquito Abatement District (ACMAD) continues to find invasive Aedes aegypti mosquitoes in new areas, including a recent detection in Dublin, a first for 2026. ACMAD initially detected the invasive mosquito in the city last year north of Dublin Blvd between Hacienda Dr and Tassajara Rd, whereas this year they were discovered in the Positano Hills area. This new detection reflects a pattern ACMAD has observed throughout Alameda County as Aedes aegypti continues to expand its geographic range.

The District is working with city officials and agencies to inform residents and check properties. “ACMAD’s quick response to the detection of Aedes aegypti mosquitoes in Dublin is deeply appreciated,” says Dublin City Council Member and ACMAD Board President Kashef Qaadri. “This is the second year in a row that invasive mosquitoes have been detected in our city, but fortunately, they continue to be found at low levels. I encourage residents to allow ACMAD’s experienced staff to inspect their yards and to do their part by dumping out any standing water in and around their homes. If you notice mosquito bites during the day, particularly around your ankles, please contact ACMAD directly. Community action, combined with ACMAD's mosquito control efforts, gives us our best chance to find and eliminate these invasive mosquitoes from our neighborhoods.”

Aedes aegypti mosquitoes, also referred to as "ankle biters", is an invasive mosquito species that is very difficult to control once it becomes established. Since their introduction to California in 2013, they have become established in the Central Valley, Southern California, and in parts of Northern California. Within the last four years, it has also been found in the Bay Area including Alameda, Contra Costa, Solano, Santa Clara, and San Mateo Counties. In response, ACMAD staff wearing District uniforms with our official logo are continuing to:

• Conduct door-to-door and community outreach to look for standing water around homes, provide information, and answer residents' questions.
• Place mosquito monitoring traps throughout the area.
• Perform mosquito control activities, where applicable.

Aedes aegypti mosquitoes are invasive mosquitoes, they are known for their aggressive daytime biting behavior and their preference for biting around the ankles. These mosquitoes have been in the United States for years, primarily in the south, but they have been consistently detected in central and southern California for over a decade. Aedes aegypti prefer to lay their eggs in containers and have a preference for biting humans. The District encourages residents in Alameda County to inspect their yards year around for standing water, which can provide breeding habitat for mosquitoes.

“This recent detection in Dublin on the last week of September underscores a key shift for ACMAD", says General Manager Ryan Clausnitzer. "Prolonged warmer weather leads to more opportunities for mosquitoes to hatch open well into the fall. As Aedes aegypti spreads throughout the state, we have the opportunity to keep numbers low with the work we do, but we need residents to do their part as well."

Invasive Aedes aegypti mosquitoes can spread diseases like dengue, Zika, and chikungunya and typically fly only short distances from where they develop, often staying close to homes and other areas where people live. Since these mosquitoes can develop in a teaspoon of water, checking your yard and removing standing water from buckets, plant propagation containers, lawn drains, and other hidden places is one of the most effective ways residents can help. If these mosquitoes become established in a neighborhood, it can significantly affect residents' quality of life because these mosquitoes are highly aggressive and active during the day.

Community action is essential for effective mosquito control.

Residents are encouraged to:

• Report unusual mosquito activity in your neighborhood to the District, especially if you notice aggressive day-time mosquito bites around your legs and ankles. 
• Remove any standing water once a week. Use our backyard list to get started on reducing mosquitoes.
• Share mosquito prevention information with neighbors and community members.
• Protect themselves from mosquito bites by wearing long, loose-fitting clothing, using EPA-registered insect repellent, and ensuring window and door screens are in good condition. 

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 when outside for three weeks and stay indoors as much as possible to avoid mosquito bites and prevent the possible spread of disease.

 

For more information, visit: Invasive Aedes aegypti in Alameda County