submitted by Becky Bartlett

On Thursday, April 23, the Pennsylvania Department of Environmental Protection (DEP) will conduct an aerial spraying for black flies (biting gnats) along the Pennsylvania portion of the Delaware River in Northampton and Bucks counties beginning at 8 a.m. The aerial spraying will utilize a helicopter to apply Vectobac 12AS (also known as B.t.i.). 

Vectobac 12AS is manufactured by Valent Biosciences. It is a thick brown liquid resembling chocolate milk and has a fish odor to it. The B.t.i. material is a naturally occurring bacteria (Bacillus thuringiensis israelensis) which kills the immature, or larval, form of the black fly when they feed on it in the waterways. B.t.i. is not toxic to fish or other macroinvertebrates found in the treated waterways and it degrades quickly in the environment. 

Black flies are considered a pest which can inundate people seeking outdoor recreation, especially around rivers and streams in the warmer months. 

The helicopter used for this operation will be N641HA, a black Bell 206 Long Ranger. The aircraft is operated by Helicopter Applicators of Gettysburg, PA. The helicopter will fly low near tree top level and release the Vectobac at various predetermined positions on the river. Application is done by first circling the area to look for people on the ground or obstructions in the air. Then the helicopter will fly perpendicular to the water flow and apply the B.t.i. material. DEP Personnel will be on site at all landing zones to manage the operation.


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