CONCORD, N.H.---No matter how much you hate 'em, black flies and mosquitoes are a fact of life in many parts of the world during spring and early summer. But did you ever consider the fact that there are some good things about these insects?
For one thing, the larvae of black flies and mosquitoes are an important food source for fish, including trout, bass and many other species. The adults also are eaten by birds, bats, and other insects.
The ecological benefits of black flies and mosquitoes are the subject of an in-depth article in the May-June issue of New Hampshire Wildlife Journal, published by the New Hampshire Fish and Game Department. The article, by Karen Finogle, suggests that black flies and mosquitoes do more than "build character" for us humans---they're part of nature's food chain.
"I guess I come down on the good side (of black flies and mosquitoes), if only because annoyance tends to be fairly temporary," said John Burger, a zoology professor at the University of New Hampshire.
Black flies breed exclusively in running water. Their worm-shaped larvae hatch and attach themselves to submerged objects. There they filter the water, consuming bacteria and other microorganisms as they clean the water.
"Black flies are suspension feeders," Burger said. "You have all this stuff suspended in the water column, and they filter it out. It's basically mostly vegetable, which they concentrate into a meat, which is then fed upon by fish and whatever else feeds on aquatic larvae."
Among the predators of black fly larvae are fish, insects, amphibians and others. The larvae are victims, as we are to black flies, and their sacrifice helps support a diverse ecosystem. And a large population of adult black flies---awful as it is for us---indicates a healthy stream, because the larvae have little tolerance for pollution.
Burger describes mosquito larvae as "aquatic cows," because they "turn plant-based organisms into meat. It's analogous to what a cow does. It takes a material which is low in energy and concentrates it into a much higher energy material, which then, other members of the food web take advantage of." And consider this the next time you're about to smack a mosquito on your arm. There are more than 2,500 species of mosquitoes throughout the world, 43 of which are known to occur in New Hampshire. Of those, only 28 species are known to feed on humans, and just 14 of the 28 species are considered to be serious pests due to their abundance. Likewise, about 2,000 black fly species occur throughout the world, but only 40 species are known to exist in the Granite State. Of those 40, only two species are considered significant human biters, and two other species are considered annoying but do not generally bite.
For more information, visit the NH Fish and Game Department's website.
