Santa Clara Co. increasing efforts to eradicate dangerous mosquito species

They can transmit diseases like Chikungunya, Dengue, Yellow Fever and Zika - viruses you normally only get if you travel.

Dustin Dorsey Image
Saturday, May 25, 2024
South Bay increasing efforts to eradicate dangerous mosquito species
Santa Clara County is moving to a day-time, wide area larvicide spraying method to target Aedes aegypti mosquito larvae.

SAN JOSE, Calif. (KGO) -- The Aedes aegypti mosquito was first found in Santa Clara County in 2022, when two were located in North San Jose. Now, the species is back and there's real concern over what the aggressive, non-native mosquitoes with a population that's increasing, might do.

"The Aedes aegypti mosquito, if it becomes established in our community, poses a serious and real threat to the health of our community," Santa Clara Co. Public Health Dept. Asst. Health Director Monika Roy said.

In April, Santa Clara County Vector Control found a few of these mosquitoes along Machado Lane in the East San Jose foothills and it's unclear how they arrived.

RELATED: Dangerous disease-spreading mosquitoes detected in Santa Clara County

Despite efforts to eliminate bugs, that number is up to at least 12 females.

This species is more aggressive and active during the day, unlike more common mosquito populations.

They are small mosquitoes with black and white stripes on its back legs.

They also don't fly long distances, traveling less than 500 feet from where it hatches.

Worry over the county's first ever infestation is growing because it's not easy to get rid of Aedes aegypti.

"Eggs from Aedes aegypti have a far-superior rate of survival compared to other mosquitoes," Santa Clar Co. Consumer and Environmental Protection Agency Director Edgar Nolasco said. "You can compare them to the cockroach of mosquitoes, they endure extreme temperatures and extreme periods without water."

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Getting rid of them will require more extreme methods.

Trying to kill off the adult mosquitoes has not worked has not worked for Vector Control.

So, the county is moving to a day-time, wide area larvicide spraying method to use bacterial insecticide to target mosquito larvae.

"This machine by itself, it has the potential to get to the sources that it's not as easy for us to have access to," Santa Clara Co. Vector Control District Manager Nayer Zahiri said.

The community can do their part by getting rid of an standing water at your home and remove items that the Aedes Aegypti like to live in, like plastic tarps.

MORE: West Nile virus-positive mosquitos found in portions of Santa Clara County

The goal is to not allow the Aedes aegypti to establish itself in Santa Clara County, like it has in 19 other counties in California.

They transmit diseases like Chikungunya, Dengue, Yellow Fever and Zika. They are viruses you normally only get if you travel. But if the mosquito is not eradicated here, they may become more common.

"Having detected the Aedes aegypti mosquito here in Santa Clara County makes us concerned that in the future, we might see something similar here where people don't have to travel to get those diseases, but just being here they're at risk for getting those," Dr. Roy said.

The county says pets and people should remain inside during the treatments set to take place over the next few months.

The first spray is scheduled for May 29 at 8:30 a.m.

County officials are holding a community meeting on May 28 at 6 p.m. at the Alum Rock Branch Library to answer any questions residents may have.

MORE: Are you a mosquito magnet? The science behind why you may get bitten more often than others

Here is the latest advice Santa Clara Co. Vector Control has for the community:

Residents should also:

  • Properly screen rain barrels, cisterns and irrigation drains to prevent mosquito access.
  • Fix leaky water faucets and broken sprinkler heads and avoid overwatering lawns and plants.
  • Ensure window and door screens are in good condition with no holes or tears and are tight-fitting.
  • Make sure the water level of swimming pools is adequate for proper circulation and filtration.
  • To protect yourself from mosquito bites:

  • Apply insect repellents containing EPA-registered ingredients such as DEET, picaridin, IR3535 or oil of lemon eucalyptus, always following label instruction.
  • Wear long-sleeve shirts, pants, socks, and shoes when mosquitoes are most active.
  • Make sure your window and door screens are in good condition.
  • Residents experiencing mosquito bites during the day should report them immediately to the Vector Control District at (408) 918-4770 or

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