PA DEP will be conducting an aerial black fly suppression operation
Pennsylvania Department of Environmental Protection will be conducting an aerial black fly suppression operation on Wednesday July 9, 2025, on the Delaware and Lehigh Rivers and the Tohickon Creek. The operations will begin after 8:00 a.m. at Washington Crossing and will include flights in Bucks, Lehigh, and Northampton counties.
The helicopter used for these operations will be a Bell OH58+ with tail number N659HA and is grey with blue and red stripes.
Spray operations will specifically take place within the following sections of each river:
- Delaware River Between Slateford in Northampton County & the area near Trenton, NJ/Yardley, PA in Bucks County
- Lehigh River Between the confluence of the Delaware River & Allentown
- Tohickon Creek Between Point Pleasant & PA 611
Helicopter Applicators Inc. will be dispersing Vectobac 12AS, which is a Bti product manufactured by Valent Biosciences. Bti is short for Bacillus thuringiensis var. israilensis, which is a bacterial larvicide, not a chemical, and is the only product used in Pennsylvania’s waterways for black fly suppression. Vectobac 12AS is a brown liquid with a fish oil odor. The helicopter will fly low near tree top level and will release the Vectobac at various predetermined positions on each stream. Vectobac is not toxic to fish or other aquatic organisms.
Please note that this work does NOT involve a helicopter spraying over the entire county and applications will only occur on the specific waterways listed in this notice. Any questions about this operation may be directed to me and more information regarding the PA Black Fly Suppression Program can be found on our website at Black Fly (pa.gov).
For more information on the program please visit the Black Fly Program website: Black Fly or click the YouTube photo below.
Product labels and SDS sheets:
Vectobac 12AS label
Vectobac 12AS SDS Sheet
