County to Conduct Mosquito Larvicide Drop Wednesday

The County of San Diego is scheduled Wednesday to drop its second round of larvicide of the year on roughly 48 rivers, streams, ponds and other waterways to kill mosquito larvae.

Weather permitting, the County’s Vector Control Program uses a helicopter to drop batches of the solid, granular larvicide on local waterways about once a month during mosquito season to help protect the public from mosquito-borne illnesses like West Nile virus.

The larvicide does not hurt people or pets but kills mosquito larvae that eat the larvicide, before the larvae can grow into biting adult mosquitoes.

The list of waterways amounts to just over 1,000 acres that stretch from Chula Vista in the south to Fallbrook in the north and from Oceanside in the west to Lakeside in the east.

The larvicide drops are just one part of Vector Control’s yearly mosquito-control program. County Vector Control also treats another roughly 1,400 potential mosquito-breeding areas each year by hand, gives out free mosquito-eating fish to the public, tracks down and treats neglected swimming pools, tests dead birds for West Nile virus and monitors cases for other potential mosquito-borne illnesses.

Vector Control officials say the public also has an important role in fighting mosquitoes and mosquito-borne illnesses, and can help by following the County’s “Prevent, Protect, Report” guidelines.

Prevent mosquito breeding

Dump out or remove any item inside or outside of homes that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires, and wheelbarrows. Mosquito fish, available for free by contacting the Vector Control Program, may be used to control mosquito breeding in backyard water sources such as unused swimming pools, ponds, fountains and horse troughs.

Protect yourself from mosquito bites

Protect yourself from mosquito-borne illnesses by wearing long sleeves and pants or use repellent when outdoors. Use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Make sure screens on windows and doors are in good condition and secured to keep insects out.

Report possible mosquito activity

Report increased mosquito activity, or neglected, green swimming pools and other mosquito-breeding sources, as well as dead birds — dead crows, ravens, jays, hawks and owls — to environmental health’s Vector Control Program by calling (858) 694-2888 or emailing vector@sdcounty.ca.gov. Also report if you are being bitten by mosquitoes during daylight hours, or if you find mosquitoes that match the description of invasive Aedes mosquitoes by contacting the Vector Control Program at (858) 694-2888.

For more information about mosquito-borne illnesses, go to San Diego County’s “Fight the Bite” website.

Gig Conaughton is a communications specialist with the County of San Diego Communications Office. Contact