Mosquito
Mosquitoes can carry West Nile virus. Image via San Diego County Twitter

San Diego County will conduct its first routine aerial larvicide drop of the year Wednesday to stop mosquitoes from potentially spreading diseases.

County officials said helicopter larvicide drops will be done Wednesday, and Thursday if necessary, to cover nearly 1,400 acres of hard-to- reach potential mosquito breeding areas in 52 local waterways.

San Diego County started using helicopters to drop solid, granular larvicide on hard-to-reach areas of standing water in rivers, streams, ponds and other waterways where mosquitoes can breed in the early 2000s after West Nile virus arrived, a statement from the county reads. The aerial larvicide drops are conducted roughly once a month from April through October.

The larvicide does not hurt people or pets but kills mosquito larvae before they can grow into biting mosquitoes.

West Nile virus is mainly a bird disease. However, mosquitoes can pass the potentially deadly virus on to people by feeding on infected birds and then biting people.

According to the county, West Nile virus’ effect has been relatively mild in San Diego County in the past few years. Three or fewer people have tested positive annually since 2017. But it can still be dangerous, and people should avoid mosquitoes.

Several types of invasive Aedes mosquitoes have established themselves in the county in recent years, requiring more of a public effort to prevent their breeding and spread.

“Some of these mosquitoes can potentially transmit diseases not naturally found here, including Zika, dengue and chikungunya, if they become infected by biting a sick person and then feed on other people,” the county statement reads. “Invasive Aedes mosquitoes prefer to live and breed around people’s homes and yards.”

The public can help by dumping out standing water near their property from containers such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires and wheelbarrows.

Mosquito fish, available for free by contacting the county’s Vector Control Program, may be used to control mosquito breeding in backyard standing water sources such as unmaintained swimming pools, ponds, fountains and horse troughs.

Additionally, the county reminds residents to protect themselves from mosquito-borne illnesses by wearing long sleeves and pants or use insect repellent when outdoors and making sure windows and screens are secured to keep insects out.

The county also asks the public to report increased mosquito activity, or stagnant, unmaintained swimming pools and other mosquito-breeding sources, as well as dead birds by calling 858-694-2888 or emailing vector@sdcounty.ca.gov.