by Residents across central Pennsylvania spotted a helicopter flying low over local waterways on May 27, 2025 — part of a scheduled black fly suppression effort by the Pennsylvania Department of Environmental Protection (DEP).
The helicopter released a natural larvicide to control the black fly (gnat) population in six creeks spanning eight counties.
What Happened
The Pennsylvania DEP launched an aerial spraying operation to combat black flies (commonly known as gnats) using a natural larvicide.
The effort targeted several creeks across central Pennsylvania and was carried out via helicopter throughout the day.
Key Details
- Date of Operation: May 27, 2025
- Targeted Waterways:
- Juniata River
- Aughwick Creek
- Conodoguinet Creek
- Conewago Creek
- Sherman Creek
- Swatara Creek
- Counties Affected:
- Huntingdon
- Juniata
- Mifflin
- Perry
- Cumberland
- Dauphin
- York
- Adams
The operation began in Huntingdon County at 11:30 a.m. and concluded in Adams County later in the day.
The helicopter used was a Bell 206 L1, tail number N660HA, with red, blue, and gray stripes on a white base.
Reactions or Statements
The York County Office of Emergency Management assured the public that the larvicide used is safe.
They confirmed that Helicopter Applicators Inc. conducted the aerial treatment using Vectobac 12AS, a natural larvicide produced by Valent Biosciences.
“Bti (Bacillus thuringiensis var. israelensis) is not a chemical. It’s a bacterial larvicide and the only product approved for black fly suppression in Pennsylvania’s waterways,” the office explained.
The released substance is a thick brown liquid that disperses from low-flying helicopters at predetermined points near tree-top level.
Investigation or What’s Next
This is part of Pennsylvania’s ongoing black fly suppression program, especially vital during warmer months when gnats become a public nuisance.
The DEP is expected to continue similar treatments as needed throughout the summer.
Residents may see additional helicopter activity during future applications.
FAQs
Q1: Is the larvicide harmful to humans or animals?
A: No. Vectobac 12AS is a bacterial larvicide, not a chemical, and is safe for people, pets, and wildlife.
Q2: Why are helicopters used instead of ground crews?
A: Helicopters allow quick, targeted treatment of large waterways and hard-to-reach areas.
Q3: How often does Pennsylvania perform these treatments?
A: The DEP conducts black fly suppression operations regularly during peak gnat seasons.
Q4: What should I do if I see the helicopter?
A: Nothing. The operation is safe, and residents are advised not to be alarmed.
Q5: How can I report a gnat issue?
A: Contact your county’s environmental office or the PA DEP to report excessive black fly activity.
Summary / Final Takeaway
On May 27, 2025, the Pennsylvania DEP conducted an aerial gnat suppression operation across six central PA creeks using a safe, natural larvicide.
Residents across eight counties witnessed low-flying helicopters dispersing Vectobac 12AS — a standard public health measure to reduce black fly populations during warmer months.
