DEP Begins 2021 Black Fly Suppression Program

The Pennsylvania Department of Environmental Protection (DEP) began its 2021 Black Fly Suppression Program the week of April 19.

The program involves aerial and backpack spraying on roughly 1,700 stream miles in 35 counties of the commonwealth.

“Black flies are a seasonal pest that can cause emotional stress to people seeking outdoor recreation,” said DEP Secretary Patrick McDonnell. “This initiative reduces the black fly population so that Pennsylvanians and visitors can fully enjoy our natural resources.”

This year, 48 rivers and streams spanning more than 1,700 miles will be monitored and t...