Mosquito season is back in the Central Valley

It's time to start applying repellent again and empty potential mosquito breeding areas.

Video Transcript

DALE YURONG: Unlike fish at the lake, mosquitoes are always biting. Climate Central defines mosquito days as those ranging from 50 to 95 degrees with a relative humidity above 42%. They're ideal conditions for mosquitoes to breed. All they need is standing water to lay their eggs.

KATHERINE RAMIERZ: You know, I'm still surprised at how many of our residents don't know that mosquitoes develop in water.

DALE YURONG: Katherine Ramirez of the Consolidated Mosquito Abatement District says you need to go around your yard and empty any standing water which could attract the striped Aedes aegypti mosquito, which is capable of carrying dangerous viruses like yellow fever.

KATHERINE RAMIERZ: This particular mosquito that bites below the knees-- we call them ankle biters-- they like flowerpot sources.

DALE YURONG: The Culex mosquito, which can carry West Nile virus, prefers larger bodies of water. Crews are now checking on homes where unmaintained green swimming pools have been reported.

KATHERINE RAMIERZ: And we do apply mosquitofish to those swimming pools or other chemicals to kill the mosquito larvae and pupae. We set mosquito traps.

DALE YURONG: Mosquitoes are also drawn to yard drains, which is why you should put some window screen under the cap to keep them out. A few years ago, an experimental treatment in the Valley involved the release of sterile male Aedes aegypti mosquitoes. A bacteria they carried kept the female's eggs from hatching.

KATHERINE RAMIERZ: That program, we saw really good results. About 85% decrease in mosquitoes.

DALE YURONG: The number of mosquito days a year in Fresno decreased from 105 in the 1980s to 89 a decade ago, due to rising temperatures in the summer. But Climate Central says the number is now rising in most cities it has analyzed. Here in the Valley, the mosquito population certainly has the potential to bring its numbers back up. Dale Yurong, ABC 30 Action News.