SWARMS OF GNATS INVADE ILLINOIS

Gnats take folks and fowl by swarm


An invasion of biting bugs in central Illinois turns spring's outdoor joys into nightmares


By Bob Secter


Tribune staff reporter

Published May 9, 2007 Buffalo gnat has a big bite

PETERSBURG, Ill. -- Swarms of tiny buffalo gnats were so thick in Todd Knoles' yard last week that his chickens cowered in their covered shed. They ran in a frenzy when he finally flushed them out, but three of the birds dropped dead, including Knoles' favorite red rooster, Copper.The toll was worse across the road, where gnats attacked Sharon Mahon as she worked her hobby farm, raising nasty welts on her head. Bugs chomped around the left eye of her miniature horse, Ghostrider, and he scratched so hard the eye bled. Mahon's chickens freaked, madly fluffing their feathers as gnats poured out like smoke. All but five of 43 birds died.
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While the Chicago area braces for an invasion of ear-splitting 17-year cicadas late this month, central Illinois is already suffering through its own insect barrage. And their bugs are definitely meaner than our bugs will be.For reasons not fully known, this has been one of the worst seasons in recent memory in these parts for buffalo gnats, a.k.a. black flies. Pesky biters, they are smaller than mosquitoes but swirl around in hordes like the dust clouds that followed Pigpen in the Peanuts comic strip.Gnat attacks have turned gardening, ballgames and other joys of spring into nightmares. Doctors have been flooded with calls from patients about allergic reactions from gnat bites that can raise golf ball-size welts. Officials at Passavant Area Hospital in Jacksonville said their emergency room treated 10 people last week, though none was seriously hurt."I've never seen anything like this," said Knoles, who saved the bulk of his small flock by herding them back into the shed, then aiming a fan at them to blow away the swarms.Buffalo gnats are hardly new to the area, but state experts say they can't remember them being so prevalent and aggressive. "Our agency deals with a whole host of diseases and pests, but this is the first time I've encountered a situation like this," said Jeff Squibb, a spokesman for the Illinois Department of Agriculture.Squibb said the agency has gotten recent reports of dead fowl from the Springfield region west to the Mississippi River, and several were sent to a lab in Galesburg for testing. The tests ruled out bird flu, it's early in the season for West Nile virus, and nothing else infectious was found. "We suspect the buffalo gnat," Squibb said.Like mosquitoes, female buffalo gnats are on a constant, vampirish hunt for blood to bathe eggs in. They are attracted to carbon dioxide and cluster around the eyes, ears and noses of their hosts.Just how gnats are involved in the recent poultry deaths is not clear, said Colleen O'Keefe, manager of the Agriculture Department's food safety and animal protection division. But she offered several possibilities:Gnat saliva can induce a strong allergic reaction, annoying in humans and larger animals, but potentially fatal in birds; gnat swarms may be so thick that birds can die of asphyxiation; and with chickens running around as if chased by phantoms, they could simply be dying of exhaustion.Nuisance to peopleThe impact appears most acute in birds, but O'Keefe said the department has also received reports of distressed horses and other livestock. People are none too happy, either.Cathy Six spent a delightfully warm afternoon last week dividing hostas and moving plants around her yard in Jacksonville. Gnats swarming her head were a frequent nuisance, and they crept into her nose, mouth and eyes, where she couldn't put repellent. But Six said she didn't realize how bad she had been bitten until hours later."I was just one big red welt after another," she explained. "My right ear was throbby and swollen."Buffalo gnats derive their name from a hump on their back, and there are more than 100 species in North America. They are a frequent nuisance in parts of Canada, less so in the U.S.Linn Haramis, an entomologist with the Illinois Department of Public Health, said buffalo gnats spread river blindness in West Africa but pose no disease threat to humans in this country.They lay eggs in streams and ponds, and adults can travel up to 10 miles in search of a good blood meal. But warmer weather chokes off the development of larva into adults.Insect populations often cycle up and down, and the reasons are not always clear. But experts think the cold, wet spring in central Illinois may have played a part in the current gnat surge. "Right now the living is easy for black flies," Haramis said.Big poultry producers, who confine birds indoors, haven't been affected by the gnats. The story is different for smaller farmers and hobbyists. Frank Bowman lost nine of the 200 free-range chickens he has been raising on his farm in Pleasant Plains northwest of Springfield.


Oddly, he said, the gnats seemed to be attracted mostly to his lighter-colored birds. All the dead ones were white.Deadly to birds

Mahon also let the birds run loose during the day on her 16-acre farm near Lincoln's New Salem State Historic Site at Petersburg. At night, however, she kept them in an uncovered coop.When she walked out to feed them early last week, she found a half dozen dead chickens in the coop. Her first instinct was to accuse a daughter of failing to give them water. The remaining birds were panting.By the next day, after giving the birds water, most of the rest were dead. And when Mahon tried to flush out two typically spirited guinea fowl who shared the space with the chickens, she watched in horror as the birds spasmed and keeled over."After they got done with my chickens, they started going after my horses," Mahon said.They also have been going after her. "You can't go out without inhaling them, and if you open your mouth, they fly in," Mahon said.The good news is that the life cycle of buffalo gnats is about three weeks. If the weather stays warm, experts don't expect another batch, and central Illinois can once again enjoy the outdoors.At least until mosquito season arrives."We'll get maybe a month," O'Keefe guessed.----------bsecter@tribune.com


Source: http://www.chicagotribune.com/features/health/chi-0705090171may09,0,2298227.story?page=1&coll=chi-news-hed