Have you heard of the dreaded black fly that pesters and inflicts painful bites on people throughout the mid-Atlantic region? Do you think you have black flies swarming and biting on your property? Here’s a guide to black flies in Pennsylvania and how to protect yourself from their nasty bites.

One Troublesome Species

Several species of black flies breed and feed along Pennsylvania’s flowing rivers. Most of them are not a problem to humans. However, the species Simulium jenningsi is particularly troublesome. According to the Pennsylvania Department of Environmental Protection, it is the most common black fly pest in Pennsylvania and loves to bite.

Black flies cause allergic reactions in some people. Bites may swell and may cause worse reactions if the victim scratches the bite. A small number of people experience severe reactions to black fly bites.

Black flies breed in moving water found in rivers and streams. Eastern Pennsylvania’s Lehigh, Schuylkill, Delaware, Lackawanna, Lackawaxen, and Susquehanna Rivers and their tributaries are ideal breeding grounds for some of the most problematic Simulium jenningsi subspecies.

Fruit Fly Resemblance

Black flies don’t look like typical house flies. They more closely resemble fruit flies in appearance. Some people distinguish the black fly from typical house and horse flies by calling the black flies gnats.

Here are a few other facts to know about the common species of black fly:

  • Swarm around human faces and eyes
  • More aggressive before storms
  • Active on warm, cloudy, and humid days
  • Least active during mid-day
  • Attracted to sweat, perfume, cologne, and scented toiletries

Bites from black flies or gnats can persist for a long time.

State Controls

Because black flies are such a nuisance to residents and tourists alike, the Pennsylvania Department of Environmental Protection oversees a program to help eradicate the annoying gnats. Called the Pennsylvania Black Fly Suppression Program, the extermination operation targets large populations of black fly larvae in over 48 Pennsylvania rivers and streams.

Helicopters are dispatched to spray a naturally occurring soil bacterium over the waters where black fly larvae remain until adulthood. This bacterium, Bacillus thuringiensis israelensis ( BTI ), targets the four main subspecies of black flies that cause problems for people.

Unfortunately, the biological control only works on the black fly larvae in waterways, so dry larvae can still survive. However, the worst black fly species can breed several times per summer in rivers and streams, so the state’s biological warfare helps reduce many black fly populations along the targeted waterways.

Effective Defense

Defense is more effective than offense in black fly management. Even though both the reproductive cycle and maturation of larvae take place in rivers and streams miles from your home, no effective treatment can cut down on black fly populations from your yard. There are some steps you can take to cut down on any painful human contacts with black flies.

Protect yourself from black fly bites with the following tips:

  • Stay indoors on warm, humid, and cloudy days.
  • Plan outdoor tasks and activities for mid-day.
  • Wear light-colored, long-sleeved shirts and pants.
  • Tuck pant legs in socks and shirt in pant waist.
  • Wear glasses, hats, and face/neck netting for maximum protection.
  • Burn smudge sticks and citronella candles.
  • Alert local officials if pest control professionals identify black flies in your yard.

Black flies hate any kind of smoke, so camp fires and fire-pit blazes can sometimes keep black flies at bay. Your pest control company can recommend additional repellents and methods to keep black flies from biting you and your loved ones. The professionals also let you know if black flies are the problem or if another type of biting insect is troubling you in the yard.

Let the experts in Montgomery County examine your yard for black flies by contacting Environmental Services Pest Control, LLC, today. We help eliminate and control a variety of flying insect pests for residents throughout the Northwest Philadelphia region.