TAMPA — If you hear a helicopter buzzing just above the treetops in your neighborhood this week, it's probably not the police. It's Hillsborough County fighting dengue.
County mosquito crews are flying low over central Tampa and Palm River during daytime hours Wednesday, Oct. 28, through Friday, Oct. 30, treating standing water to kill mosquito larvae before they can grow into biting adults, according to a Hillsborough County announcement. At the same time, airplanes are spraying for adult mosquitoes over much of the county at night.
The county says it's stepping up treatments by air and on the ground because mosquito traps in many neighborhoods are turning up dengue virus. Hillsborough has reported more dengue cases than anywhere else in Florida this year, the Tampa Bay Times reported.
Daytime helicopters: where
Central Tampa, roughly from Carrollwood to Temple Terrace:
- North: Fowler Avenue
- South: I-275/I-4
- East: North 50th Street
- West: Dale Mabry Highway
Palm River:
- North: Selmon Expressway
- South: Alafia River
- East: U.S. 301
- West: Hillsborough Bay
Expect a lot of noise. The county says the helicopter will fly just above trees and buildings, making straight, parallel passes over homes and businesses, and may go over the same property more than once. You may be able to see the spray.
What they're spraying
The helicopters are dropping liquid Bti, short for Bacillus thuringiensis israelensis, a naturally occurring bacterium that targets the larvae of mosquitoes and a few other insects. The county says it doesn't harm people, pets, fish, birds or beneficial insects, and it breaks down naturally. You don't need to leave the area, according to the county's spray product safety page.
One practical note: Bti can leave a white residue that washes off with water. The county says leaving it on your car for a long time can mean more scrubbing later.
Nighttime airplanes: a much bigger area
Separately, contractors are spraying for adult mosquitoes from airplanes between sunset and midnight through Friday, covering about 225,000 acres from Carrollwood to FishHawk Ranch, according to an earlier county announcement. The planes fly at about 300 feet.
The nighttime list includes Carrollwood, Town 'N Country, South Tampa, the USF area, Temple Terrace, Seminole Heights, East Tampa, downtown Tampa, Davis Islands and Harbour Island, Thonotosassa, East Lake, Mango and Seffner, Palm River, Progress Village, Gibsonton, Riverview, Apollo Beach, Plant City, Dover, Brandon, Bloomingdale, Boyette and FishHawk.
The planes use Dibrom, an EPA-registered insecticide sprayed in very small amounts. The county says it's safe when used according to the label. To cut your exposure, the EPA recommends staying inside with the windows closed while spraying is underway and keeping young children from playing outside for four hours afterward, the county's mosquito FAQ says. The county also suggests bringing pets inside during spraying.
What you can do
The mosquitoes that spread dengue, Aedes aegypti and Aedes albopictus, bite mostly during the day and breed in small containers around homes. The county's advice is the “3 Ds”:
- Dress in light-colored, long-sleeved clothing and closed-toed shoes.
- Defend with a repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus.
- Dump or cover standing water in buckets, flowerpots, pet bowls and anything else that holds it.
Old tires are a common breeding spot. Hillsborough Solid Waste customers can drop off up to 12 tires a year for free at any of the county's five collection sites.
To see where crews are treating, check the county's mosquito operations page. You can also sign up for alerts when aerial treatments are scheduled near you. Questions go to Hillsborough County Mosquito Management Services at (813) 635-5400.
Across the bay, Pinellas County has been running similar helicopter larvae treatments, which TBO covered last week.