Black flies are insect pests that are notorious for their nuisance swarms and painful bites. Black flies are well known to residents and vacationers in the Adirondacks and other areas in upstate New York. Most of the 255 black fly species that have been documented in North America lay their eggs within flowing water, while a minority of species plant their eggs on wet vegetation, namely blades of grass. Black flies are distributed all over the US, but the northeast sees the largest number of species as well as the greatest amount of reports describing nuisance and medically significant encounters with these flies.
Upstate New York residents sometimes encounter black fly swarms on their property, and residents living near bodies of water often see the flies swarm onto their property repeatedly during the late spring and summer months. Black fly swarms are particularly common on properties where flowers are prevalent, as male black flies feed on nectar and flower pollen. The females, however, prefer to collect blood meals from poultry and livestock, but they will not hesitate to suck the blood of humans. In fact, bites are quite common in and near wooded areas where streams and creeks can be found. One man claims that he has sustained more than 200 black fly bites around his neck in one single day while fishing near his vacation home in the Adirondacks.
Numerous residents of upstate New York struggle to control black fly swarms on their property every summer, but unfortunately, there exists very few pest control methods that have proven effective at repelling black flies. Many residents have become used to fleeing into their home whenever swarms appear, but there are ways to minimize the chances of winding up in the middle of a swarm. For example, black flies gravitate toward anything that is dark-colored, including houses, boats, cars and humans, so wearing light-colored clothes is a must. Some sources claim that repellents containing DEET are not only ineffective at preventing black fly bites, but these repellents may actually attract black flies, but other sources claim that DEET repellents provide some protection against black fly bites. Evidence suggests that repellents containing Permethrin effectively repel black flies, and spraying clothes with .5 % Permethrin spray may also keep the flies at bay. Black flies are hard to avoid during May through August, but negative encounters are most common during the late spring and early summer seasons. It is also worth noting that aggressive black fly swarms emerge on calm sunny days when the temperature is around 75 degrees. Black fly swarms do not emerge on windy, cloudy and rainy days.
Have you ever sustained a black fly bite?