PA Begins Statewide Program To Kill Biting Black Flies

HARRISBURG, PA — Pennsylvania has begun an aggressive anti-pest program statewide aimed at eliminating black flies.

The suppression program will utilize what the Department of Environmental Protection called "a naturally occurring bacterium." Bacillus thuringiensis serotype israelensis, or Bti, is commonly used in mosquito and fly control efforts.

“Pennsylvania is full of beautiful state parks, trails and forests. People across the Commonwealth should be able to enjoy nature without this seasonal pest impeding on their time,” said Acting Secretary of DEP Rich Negrin. “Our black fly suppression program ensures safe and effective treatment of the black fly species.”

A total of 48 rivers and streams spanning 1,800 miles across 37 counties will be sprayed. Local and county emergency officials will be notified before spraying occurs.

A full list of waterways that will be treated has not yet been published by the state, but in the past has included the state's largest rivers like the Delaware, Susquehanna, Allegheny, Schuylkill, Ohio, and more. Patch has reached out to DEP for more details.

The DEP says that the Bti spray is not toxic to fish, birds, or other aquatic life. It will be deployed both by state workers using backpacks, and via helicopters.

"Anyone concerned at the sight of a helicopter or ground personnel is encouraged to call their county emergency management office to verify that a black fly treatment is taking place in their area on that day," the state added.

While black flies can annoy humans to end by biting, they do not transmit disease, and are an important part of a healthy ecosystem.