Helicopters Spray Bacteria Over Pinellas to Halt Dengue Spread

Two helicopters are set to fly low over Pinellas County on Thursday, releasing a fine mist of bacteria to target mosquito larvae in St. Petersburg and Clearwater.

The operation is a joint effort between Pinellas County Mosquito Control and Lee County Mosquito Control. The need for aerial intervention grew as the Florida Department of Health released a report on Oct. 30. That report confirmed 67 dengue cases in Pinellas County since August. Across the Tampa Bay region, including Pasco and Hillsborough counties, health officials have confirmed 456 total cases.

The flight schedule begins early in the morning. Pilots will start mapping the treatment zones in the St. Petersburg area between 8 a.m. and 9 a.m. Actual spraying will not commence before 9 a.m. The operational window runs until 3 p.m. Low altitude is required for the mist to reach standing water effectively, though the noise may be disruptive for residents.

The active ingredient is Bacillus thuringiensis israelensis, commonly known as Bti. It is a soil bacterium that targets the unique gut pH of mosquito larvae and black flies. The bacteria release a toxin when ingested. This is the same ingredient found in commercial mosquito dunks and bits sold at hardware stores. Officials note that Bti is not harmful to humans, pets, or pollinators, making the 9 a.m. to 3 p.m. window a practical time for residents to stay indoors.

Residents can track specific treatment zones by visiting the aerial tab on the Pinellas County mosquito control website. Those wishing to receive automatic alerts for future flights can register at the Alert Pinellas portal. The county directs those seeking further protection details to the Pinellas.gov/Dengue page.

The latest data from the Florida Department of Health serves as the primary driver for this week's aerial operations. The 67 confirmed local cases represent a subset of the 456 regional infections recorded since the start of the season.