Killer files attack nubile teens on a beach in Glencoe, one of Chicago's glitzier northern suburbs, forcing the young girls into the icy depths of Lake Michigan.
They sought refuge from the heat at the beach, and found none. The flies attacked by land, and bitter cold by water.
"It's like a million needles in your face," groaned 14-year-old Sarah Rustman at a beach in Glencoe, where in 24 hours water temperatures fell from the 70s to the 50s Wednesday.
Her friend Lexi Assimos likened a dip in the lake to plunging into an instant ice cream headache.
"It was so cold, my neck was stinging," said Assimos, also 14.
But it beat languishing on a shore that hummed with a bumper crop of stable flies—officially Stomoxys calcitrans, and identical to the housefly except for its piercing mouth, slashing mandibles and lust for blood.
And the heat has brought swarms of them.
Basically, the heat wave we've suffered in the last few days has helped the flies breed prodigiously. And the southwest winds which have brought all the hot air have also blown all the warm water off the surface of the lake, drawing up much colder water from below.
The lake-flipping phenomenon happens every time the wind blows from the southwest. The flies come every summer.
But a combination of factors contrived to magnify both.
Long periods of hot, humid weather bred generations of fly larvae in shoreline algae, wriggling in sumptuous numbers to emerge hale, refreshed and thirsty for blood protein drawn from the backs of human legs.
Swarms chased visitors in Highland Park up the beach, down wooded paths and back to their cars. A man with a can of bug repellant declared it useless. At Glencoe's beach, summer camp counselors were reduced to ridiculous contortions as they slapped at the nettlesome, biting flies. In Evanston, the flies were a low cloud stalking across the beach.
Ankles grew puffy. Tempers grew short.
But people do just fine too, and over time, the fly has evolved the habit of biting low—out of swatting range—said entomologist Donald Webb of the Illinois Natural History Survey.
The result is a bug so irritating even insect researchers dread it.
"Now I'm not going down to the beach. In such huge numbers? Forget it," said Summers, sullen as a jilted lover. "It'll just keep coming back and coming back—the same one-until it gets what it wants. It's like somebody sticking you with a pin."
I hate bugs. One of my favorite days of the year is the first freeze, because it kills the lot of them.