Spraying operation to target Aedes aegypti mosquito in Visalia

FRESNO, Calif. (KFSN) -- Aedes aegypti mosquitoes can spread Zika, dengue, chikungunya, and yellow fever virus.

Officials with Delta Vector Control District say California isn't seeing any transmission of those diseases right now.

Still, they're known to bite-often more than once at a time and like to lay their eggs near homes.

"Aedes aegypti prefer freshwater sources and they prefer small water sources," Delta Vector Control District Assistant Manager Mir Bear-Johnson said. "We most often find them in plant trays, in yard drains, and in miscellaneous containers."

Recently, 42 female Aedes aegypti mosquitoes were found in a single trap in southeast Visalia, prompting the district to start spraying a larvicide in the surrounding neighborhood.

The bacterial insecticide, called Bti, doesn't harm humans, animals, or honeybees, and only targets Aedes aegypti larvae.

"Then when the potential water sources either have water put into them or they already have water in them, and then the mosquito lays their eggs, the mosquito larvae consume the Bti product and therefore die," Bear-Johnson explained.

Joel Glick says mosquitoes have been especially bad in his neighborhood this year.

"That's great news," Glick said about the spraying. "Hopefully, they'll get our neighborhood. As we speak right now, I'm getting bit."

Visalians can do their part to help reduce the number of Aedes aegypti mosquitoes by making sure they don't have any standing water in their yards.

The district will spray overnight once a week for four weeks, then once every other week for another four to eight weeks.

"We are going to continue to trap there for the duration of the operation, see what the numbers do," Bear-Johnson said. "We also monitor service requests, so we'll be seeing if we're getting more, fewer service requests from that area."

Aedes aegypti mosquitoes do not spread West Nile virus.

The Culex mosquito does, and so far this year, there have been no human cases in Tulare County.

Last year, there were seven.