Evening Control Program

West Nile Truck
Vector Control conducts an Adult Mosquito Control program responding to residential areas where high adult mosquito populations exist or have tested positive for West Nile Virus. Sign up for notification of future spray events.
The control program uses an Ultra-Low Volume (ULV) spray which disperses fine droplets into the air.

Adult Mosquito Control:
    • This product degrades quickly in sunlight, and therefore it has a short residual time in the environment.
    • The active ingredient in this product is similar to that used in dog flea and tick prevention medication.
    • Biomist is registered for and is safe to use in and around food crops, livestock, commercial, and residential areas.
    • Although safe, common sense precautions should be used when applications are scheduled:
      • When possible, don't walk through fog cloud and stay indoors during applications
      • Refresh pet watering bowls
Map of spray route published during mosquito season, May - September:
Zoom in above or View Larger Map.

Spraying is scheduled evenings, 6-11 p.m. since adult mosquitoes are most active after dusk.

Ideally, you may wish to avoid being outside at the time your area is being sprayed. If the truck is spraying while you are out, avoid being directly in the spray path. The nozzle on the truck is angled upward and the material droplet sizes are intended for the material to rise and travel in the slight breeze. Generally, the material travels with the direction of the breeze.  The truck operator will discontinue spraying within 500 feet of a passerby.
Truck mounted Ultra Low Volume Sprayer is used to distribute an adult mosquito control spray product (PDF).  The product is designed to provide quick, effective control of adult mosquito populations. The application material has a very low toxicity profile to mammals and will have negligible impact to non-target insects and the environment.

Important Notice
PA DEP NPDES permit limits areas that can be treated with truck mounted ULV as was done in prior years.
Location of spray application is dependent upon proximity to Exceptional Value (EV) and High Quality (HQ) streams.  Generally, some South Mountain areas of the county can no longer be considered for truck ULV treatment due to the presence of HQ and EV streams such as the Yellow Breeches and tributaries.

Barrier backpack sprayer applications may be given consideration as perimeter treatments.