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Black Flies Beware: Potomac River Undergoing Treatment
2 Sep
Summary
- Maryland officials will treat the Potomac River near Harpers Ferry.
- A helicopter will apply a natural larvicide called Bti.
- The treatment aims to reduce black fly populations, starting Sept. 2.
Maryland officials are scheduled to conduct a targeted treatment of the Potomac River near Harpers Ferry on September 2nd, between 9 a.m. and 11 a.m. This initiative aims to reduce nuisance black fly populations in the area.
A specialized helicopter, identified as Bell 206 Long Ranger with tail number N660HA, will be used to apply a larvicide. The larvicide contains Bacillus thuringiensis israelensis (Bti), a naturally occurring soil bacterium known for its effectiveness against specific insect larvae.
Bti is a selective insecticide, primarily affecting black flies, midges, and mosquito larvae, while posing no significant threat to drinking water, fish, or other aquatic organisms. Residents may observe temporary discoloration in the river post-treatment, which is harmless and will naturally dissipate.
This black fly control program began in 2016 due to ongoing concerns from Washington County residents. Additional information on Bti and the state's Black Fly Program is available through provided online resources.
