Bug bites still have officials scratching their heads
James Janega, Chicago Tribune
12:51 PM CDT, August 15, 2007
After a second night of setting out sticky traps for the mystery bug behind all the bites in northern Illinois, state public health officials had yet to announce a positive identification this morning. But attention centered on a tiny mite that plagued Kansas and Nebraska in 2004—the oak leaf gall mite, Pyemotes herfsi, an invasive species and close relative of the European straw itch mite.
Though state health officials were circumspect about naming the suspect, emergency room doctors have been downloading and printing the Kansas studies for days, and articles about the mites are hot on Internet search engines. State officials have been consulting with experts in Kansas and Nebraska.
Much of what is known about the oak leaf gall mite has been learned from those Midwestern studies in the last few years. The mite is known to eat the larvae of a particular kind of midge, said Field Museum entomologist Daniel Summers. But it also finds immature members of the Homoptera family to be delectable, he said.
That family includes the periodic cicadas, the noisy bugs that flooded the Chicago area to mate earlier in the summer. The next generation of nymphs are emerging now, presenting an irresistible food source to any Pyemotes mite looking for something to eat. "They're hatching out right now in the forest preserves by the countless zillions," Summers said. "It would be an endless feast for them. That would be my best guess right now."
Guesswork remained the order of the day for residents from Wooster Lake near the Wisconsin border down to Champaign and from Aurora east to Crown Point, Ind. "Right now, we haven't determined the exact culprit," said Cook County Public Health Department spokeswoman Kitty Loewy. "I think that the type of mite is important to learn, but I don't think it's going to change the message."
The message is to wear long clothing, launder clothing often and shower after being outdoors near foliage, which would remove any mites before they begin munching at human skin in search of nonexistent larvae. Something as simple as sunscreen may foil the mites' exploratory nibbling, Loewy said. If bitten, treat with hydrocortisone cream and antihistamine.
Don't scratch, officials say—you'll only infect the bites. Experts also warn that if redness from the wounds grows larger than a quarter or if streaks of red reach from the bite sites toward the chest, call a doctor or visit an emergency room; those may be signs of secondary infection from scratching.