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University of Illinois Extension

Biting Gnats Have Returned

June 20, 2014

“You may have noticed lately in northern Illinois that some insects are of a particular nuisance this summer,” states Extension horticulture educator, Candice Miller. “In particular, many people have been complaining about small, black biting insects.” These insects are called buffalo gnats or black flies.

Buffalo gnats are small, 1/16- to 1/8-inch-long, humpbacked black flies. They bite exposed skin, typically leaving a small, red welt. This of course is a nuisance to us, but when the gnats are numerous, the toxins from their bites can kill poultry and other birds. They feed on the thinly haired areas of dogs, cats, and horses, such as ears and undersides.

.Extension Entomologist, Phil Nixon notes that many buffalo gnat species live as larvae in clear, fast-moving streams and feed by filtering food from the water. Adult buffalo gnats can fly from 7 to 15 miles from their source; but generally, Illinois residents that are bothered live within a half mile of the stream producing the flies. Although there are reports of DEET-containing insect repellents not being effective, scientific literature reports that DEET repellents provide the most effective protection. In areas with high populations of buffalo gnats, people commonly wear head nets, hats with insect protective netting that covers the head down to the shoulders. These are sold in sporting goods stores. Unlike mosquitoes, buffalo gnats do not bite through clothing, so only exposed skin is susceptible to attack. They also do not enter buildings.

“Protecting ourselves through the use of repellents and protective clothing is really the best option for buffalo gnat control, as controlling the larvae or adults through use of pesticides is not feasible,” notes Miller.

For more information about pest problems in the area, follow our Northwest Illinois Extension Horticulture Facebook Page: https://www.facebook.com/northwestillinoishorticulture

Source: Candice Hart, Extension Educator, Horticulture, mille116@illinois.edu

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