Press Releases


Westerly to Apply Mosquito Larvicide to Swamp Areas on Thursday, May 16 in Yearly Routine

PROVIDENCE - The Town of Westerly, as it has done on a routine basis each year since 1997, will apply granules of mosquito larvicide by helicopter to 500 acres of swamp to control mosquito breeding. The targeted areas are portions of Chapman Swamp and the swamp area adjacent to Hespar Drive. The town is notifying adjacent landowners of its intent, as well as the general public, that it plans to apply the larvicide on Thursday, May 16, between 7 a.m. and 2 p.m. The larvicide may also be applied on future dates after notification by the town. May 17 and May 20 have been designated as rain dates. The Department of Environmental Management approved the town's application to apply the larvicide Bti for mosquito control to the targeted areas.

Bti is a naturally occurring bacterium, which is applied in granular form to swamps and other mosquito breeding habitats to prevent larval mosquitoes from developing into adults. It is extremely safe from both an environmental and human health standpoint. Larviciding by communities is recommended as part of the state's action plan for West Nile Virus and Eastern Equine Encephalitis (EEE), and is the best way for communities to reduce mosquito numbers and risk.

The state is not advocating wide-scale aerial application of larvicide, and it is recommended that most communities apply larvicide by hand into roadside catch basins. Westerly's Chapman Swamp area is unique because of its large size and its inaccessibility and because of the presence there in 1996 and again in 2003 of mosquitoes carrying the EEE virus. Westerly began using the larvicide Bti on a yearly basis in 1997 after the EEE virus was first found in mosquitoes breeding in Chapman Swamp.

Related links

  • Department or agency: Department of Environmental Management
  • Online:
  • Release date: 05-15-2013

Share this: