With spring finally here it is time to open the windows, air out the house, go outside, and enjoy the sunshine and fresh air. Take a trip out into the woodland or park to look for wildflowers and watch the warblers and other colorful birds that are flying north to their breeding grounds. But all of a sudden….ouch. What just bit me? I don’t see any mosquitoes flying around yet, what could it be. Look it is getting red, swollen and it is really itchy.
Well it is Black Fly season in Ohio! Black fly season occurs from mid-March to mid-July in Ohio, Pennsylvania, New Jersey, and north through New York and New England, the Upper Peninsula of Michigan and into Southern Canada. OK wait a minute, what the heck is a Black Fly?
Black flies, known also as “Russian soldiers”, “buffalo gnats” and “turkey gnats,” are very small, robust flies that are annoying, biting pests of wildlife, livestock, poultry, and humans. Black flies are small black or grey insects with short legs and antennae. Bites can be extremely painful, and their mouthparts are similar to those of a horse fly. Some species of adult black flies prefer humans whereas others target specific animals or birds. On people, they crawl into sleeves and around boot tops, especially favoring the head just beneath the rim of a hat. Black flies often swarm around a person’s head because they are attracted to carbon dioxide in the breath. Bites can cause swelling and soreness for many days. There are records of both domestic animals and people being killed in a few hours through bites and blood loss, however that is a very rare occurrence. Like mosquitoes, black flies gain nourishment by sucking the blood of their host. Again like mosquitoes, it’s just the females who feed on blood; the males feed mainly on flower nectar. However unlike mosquitoes, black fly eggs are laid in moving water where the larvae attach to rocks using tiny hooks and survive under ice, waiting for the spring thaw. There, they pupate under water feeding on passing organic debris and emerge in a bubble of air as flying adults. When they hatch, they are often preyed upon by fish. They live about 4-6 weeks, depending on species, temperature, and food supply. Black flies are most active a couple of hours after sunrise and a couple of hours after sunset. Although they are strong fliers, they are less of a nuisance on windy days and in open areas than on calm days and in sheltered areas like the woodland.
Black flies are true flies (Order Diptera) in the family Simuliidae, which includes more than 1,700 species worldwide. In North America, 255 species in 11 genera have been identified, but additional species remain to be discovered and named. Not much is known about black flies in Ohio; to date there are 27 species in 4 genera.
There is little that a homeowner or person engaging in outdoor activities can do to control black flies. For personal protection, it is best to avoid peak periods of black fly activity. Black flies are small enough to pass through window screen or come indoors on or in the hair. They do, however, prefer to bite out of doors. Repellents containing “DEET” formulations are not very effective for prevention of black fly bites. Individuals wearing DEET may actually have more black flies attracted to them than individuals not wearing DEET. Proper clothing offers good protection against black fly bites. Black flies are strongly influenced by color, they find dark hues more attractive than pale ones, with blue, purple, brown, and black more attractive than white or yellow. A light-colored shirt, therefore, is a much better choice of clothing than a dark blue one. Keep shirt sleeves and front closely fastened and tuck trousers inside socks or high boots. Zippered front shirts will keep flies out better than button shirts. When it gets really bad, shoulder-length head nets are sometimes useful.
