In the midst of mosquito season, the County of San Diego Vector Control Program (VCP) will conduct its fifth aerial larvicide treatment for mosquitoes next week at four dozen locations across the county.
VCP plans to conduct the drops on July 19 at 48 locations with large water bodies known to breed mosquitoes including areas in Escondido, Rancho Bernardo, 4S Ranch, Rancho Santa Fe, San Diego, Lakeside, Santee, Chula Vista, Encinitas, Solana Beach, Carlsbad, Oceanside, and Fallbrook. This includes Rancho Bernardo Lakes, the San Diego River/Town Center area in Santee and the Otay River at east and westbound Interstate 805 in Chula Vista. The full list of sites can be found here. In all, the areas that will be treated span a combined 1,004.45 acres.
Depending on mosquito counts, the VCP conducts these aerial larvicide drops every three or four weeks throughout the mosquito season, which typically lasts from April to October. This will be the fifth such treatment this year; others are slated for Aug. 9, Aug. 30 and Sept. 20 – as well as Oct. 18, if necessary.
According to the county, a helicopter is used to drop the solid larvicide. VCP staff will be on-hand at each location during the application to answer questions about the process.
The process aims to reduce the number of mosquitoes that can grow into biting mosquitoes and spread diseases like West Nile Virus. The best protection against the illness is to prevent mosquito breeding and mosquito bites.
The VCP website says the granular larvicide is made of naturally occurring bacteria that target mosquito larvae in the water. It is not toxic to people, pets, wildlife or plants but is deadly to mosquito larvae.
This video explains the aerial drops:
The county offers information about West Nile Virus, Zika, and tips on preventing mosquito bites on this "Fight the Bite" website. This includes dumping any stagnant water and checking for spots around your home where still water may pool, such as clogged rain gutters, rain barrels, and pet bowls.