The state started black fly suppression spraying operations in several counties on April 9th.   Spraying usually begins in late April or early May, but it has started earlier this year.

Amanda Witman, spokeswoman for the Pennsylvania Department of Environmental Protection, says surveillance detected the flies a few weeks earlier, but that does not mean they’re out in increased numbers.   That’s what the spraying is intended to prevent, by targeting the larval stage of four types of black flies that are pests to humans.  

Spraying is scheduled for 44 waterways in 33 counties. Witman says they plan to cover 1500 stream miles, which is a little less than last year.

Witman says the spraying uses BTI, a naturally occurring bacterium, which degrades quickly in the environment and does not hurt the ecosystem.  It is sprayed from low-flying helicopters, and spraying operations depend on weather conditions.

Witman says people living along the waterways should be familiar with the program. It has been around for many years. It covers large rivers like parts of the Susquehanna, Delaware and Juniata as well as smaller streams.

Witman says if you’re new to an area and concerned about a low flying helicopter, there are ways to check whether spraying is scheduled for that day. DEP notifies local Emergency Management officials about any spraying activity.  You can also get more information about the Black Fly Suppression Program at DEP’s web site.