PA Begins Black Fly Suppression Program

PENNSYLVANIA — The Pennsylvania Department of Environmental Protection has begun its 2023 black fly suppression program and will use aerial and backpack spraying on approximately 1,800 stream miles in 37 of the state's 67 counties.

According to the World Health Organization,black fly bites can cause onchocerciasis, an eye and skin disease. Symptoms can include severe itching and various skin changes. Infected people also can develop eye lesions that can lead to impaired vision and permanent blindness.

The department is using Bti, a naturally occurring bacterium, to treat the larval stage of four specific potentially harmful black fly species. This bacterium degrades quickly in the environment and does not harm the aquatic ecosystem, birds or other insects.