VISALIA, California (KSEE) — October is usually when the number of mosquitoes declines – but in some parts of Tulare County the number is going up.
While the number of diseased mosquitoes is down from last year, mosquito-transmitted diseases like West Nile virus are still being found in humans.
Inside the lab at the Delta Vector Control District, one water sample contains an abundant amount of larvae. Petri dishes also line the counters, filled with hundreds of mosquitoes caught in traps.
General Manager Dr. Mustapha Debboun said the Central Valley’s prolonged heat has made ideal mosquito breeding conditions.
Recently, there’s been an uptick in neighborhoods in northwest Visalia. The district conducted targeted treatment in some of them Thursday morning. However, the number of mosquitoes found carrying viruses is down from 2019. So far, only 139 mosquitoes have been found with West Nile virus, while 39 have been found with St. Louis Encephalitis virus.
“If you compare what happened last year, we had about 400 mosquito samples that were positive with West Nile virus,” Debboun said.
The invasive species Aedes aegypti — carriers of dengue, or yellow fever — have also been found in Tulare County.
Debboun said they have to get creative to take care of those.
“Most of the Aedes aegypti has already developed resistance to pesticides,” he said. “They also live with humans. They live in the containers in the front yard or backyard, even in the house, or in the flower pots.”
So far, the Tulare County Health and Human Services Agency has reported five human West Nile virus cases. One more potential case is under investigation.
Carrie Monteiro with Tulare County’s Health and Human Services Agency, says the best way to prevent these diseases is to not let mosquitoes bite you and to eliminate any standing water.
“Be aware of when mosquitoes are most active during the day, such as dusk and sunset hours. During those times, if you’re outside, wear long sleeves and pants.”
You can also use insect repellent (so long as it is EPA approved).
Delta Vector Control District, as well as other mosquito abatement districts, are more than happy to provide tailored help for your property if needed.