Mosquito Spraying To Happen In Waltham Soon

WALTHAM, MA — Officials are about to start spraying for mosquitoes. So, if you happen to hear or see a helicopter over Waltham between April 22 and April 26, it's likely that's what's up. The East Middlesex Mosquito Control Project will be spraying a biological larvicide called Bti from helicopters to control mosquito larvae over a large wetland area near Cartwright Road, according to officials.

Although it's unclear if it will take more than one day, watch for a helicopter to show up between April 22nd and April 26. The Bti will be applied in a granular formulation by a helicopter flying low directly over the wetlands.

Officials say residents do not need to take any special precautions for this application.

The material to be applied Bti (Bacillus thuringiensis var. israelensis) is a natural bacterium found in soil. The EPA classifies Bti as a relatively non-toxic pesticide.

Bti is considered a target selective and environmentally compatible pesticide that affects mosquito larvae and a few closely related aquatic insects in the fly family. Once applied, Bti stays suspended in water for 24 to 48 hours and then biodegrades as it settles to the bottom.

Patch reporter Jenna Fisher can be reached at Jenna.Fisher@patch.com or by calling 617-942-0474. Follow her on Twitter and Instagram (@ReporterJenna).