DEP

Black fly spraying

update

The Pennsylvania Department of Environmental Protection on May 3 conducted an aerial and backpack spraying spraying for black flies (biting gnats) between the mouth of the river in Easton to the confluence of Saucon Creek in Freemansburg and to the Trenton, N.J. city limits.

The spraying material is Bacillus Thuringiensis Israelensis a naturally occurring bacteria) which kills the immature, or larval, form of the black fly when they feed on it in the waterways. The degradable B.t.i. is not toxic to fish or other macroinvertebrates found in the treated waterways.

Black flies are encountered especially around rivers and streams in the warmer months. This year, DEP will spray roughly 1,700 stream miles in 35 Pennsylvania counties in an effort to control black flies.