Published on Thursday, May 08, 2025
PROVIDENCE, RI – The Rhode Island Department of Environmental Management (DEM) is announcing that the Town of Westerly will conduct its annual aerial mosquito larvicide treatment across 500 acres of Chapman Swamp and nearby swamplands on Friday, May 9, or Monday, May 12, weather permitting. The application will occur between 7 AM and 2 PM and involves dropping Bti pellets by helicopter on targeted waterbodies to kill mosquito larvae. Bti is a natural, environmentally safe product that targets only mosquitoes, black flies, and fungus gnat larvae, posing no risk to humans, animals, or beneficial insects like honeybees.
The Town of Westerly has conducted this annual application since 1997 to help control mosquito breeding, given the area’s remote location and large footprint. Larviciding is recommended as part of the state's action plan to control West Nile Virus (WNV) and Eastern Equine Encephalitis (EEE) Virus, and is one of the most effective tools to reduce the number of biting mosquitoes by preventing the larval stage from maturing into adults.
More information about larviciding and mosquito season is available at www.dem.ri.gov/mosquito. For mosquito public health guidance and information from the Rhode Island Department of Health (RIDOH), visit health.ri.gov/mosquito.
For more information on DEM programs and initiatives, visit www.dem.ri.gov. Follow DEM on Facebook, Twitter/X (@RhodeIslandDEM), or Instagram (@rhodeisland.dem) for timely updates. Sign up here to receive the latest press releases, news, and events from DEM's Public Affairs Office to your inbox.
