DEP's Black Fly Suppression Program involves aerial and backpack spraying on roughly 1,700 stream miles in 36 counties in the commonwealth. The season runs April 1 through September 2022.
48 rivers and streams spanning more than 1,700 miles are monitored and treated as needed. Spraying activities are performed both by helicopter and ground crews. Prior to any spraying activity, DEP notifies county and local emergency management officials. Helicopters can be seen flying over waterways and ground crews using backpack sprayers off bridges and wading in streams conducting control operations on behalf of DEP’s Black Fly Suppression Program. 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.
For more information on DEP’s Black Fly Suppression Program, visit dep.pa.gov/blackfly.