HAYWARD, CA September 21, 2026 – Recently the Alameda County Mosquito Abatement District (ACMAD) has found numerous invasive Aedes aegypti mosquitoes in Livermore between S Vasco Rd, East Ave and Hillcrest Ave. Aedes aegypti is an invasive mosquito that can transmit diseases such as dengue, chikungunya, and Zika. To reduce Aedes aegypti mosquitoes, ACMAD staff have gone door to door to inform residents and inspect yards for mosquito sources.

Based on their findings, ACMAD will conduct an wide area larval treatment starting at 11pm on Tuesday, September 22nd and into the early morning hours of Wednesday, September 23rd. This treatment will target mosquitoes in their larval stage before they start to fly.

Additional Details

• Public Health Insecticide: VectoBac® WDG (Active ingredient: Bacillus thuringiensis subspecies israelensis (Bti))
• Bti is a natural bacterium that targets mosquito, black fly, and fungus gnat larvae. It is safe for humans, pets, and other animals, including pollinators. 
• All public health insectides used are registered with the US Environmental Protection Agency (EPA) and are regulated by state and local government agencies.
• Method: Truck-mounted ultra-low volume sprayer 
• What residents should know:
• Residents are encouraged to stay indoors during these hours with windows and doors closed and bring pets indoors.
• Air conditioning can remain on.
• Please allow District staff to complete the treatment without interruption.
• You may notice a light residue on outdoor surfaces after treatment. It will wash away with water and can safely drain into the sewer.
• Fruits and vegetables are safe to eat after treatment. Wash them as you normally would before eating.
• Location: Between S Vasco Rd and Hillcrest Ave, bordered by East Ave and N. Mines Rd/Charlotte Way (see map below). 

“Similar to last year, we are seeing these mosquitoes fly and bite in late summer and early fall, when most people don’t expect to see mosquitoes,” says Public Education Officer Judith Pierce. “We appreciate every resident who has allowed our team to check their yard for standing water. We are finding a variety of sources where these mosquitoes can thrive. Mosquitoes don’t need much—just a tablespoon of standing water can allow their eggs to hatch. We need residents throughout Livermore to remove standing water and limit the number of containers in their yards, which will reduce opportunities for invasive mosquitoes to thrive.” 

Local community cooperation 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 standing water once a week. This can include buckets, plant saucers, lawn drains, and other hidden sources in and around your home. Use our backyard list to get started on reducing mosquitoes.
• Protect yourself from mosquito bites by wearing long, loose-fitting clothing, using EPA-registered insect repellent, and ensuring window and door screens are in good condition. 
• Sign up for treatment notifications and other news from ACMAD.

The District remains committed to protecting public health through ongoing mosquito monitoring, mosquito control, and community education throughout Alameda County.

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