Yellow jackets have it in for us this summer

September 8, 2005

BY GARY WISBY Environment Reporter

You hear it a lot: "Aren't the bees terrible this summer?"

No, they're not. But the yellow jacket wasps are.

The wasps are turning surly and stinging people like they do at the end of every summer, insect experts say.

But this year's extreme drought makes it even worse, partly because the yellow jacket's normal sources of water have dried up. So it's looking for a drink or a snack where people are -- at picnics, for example.

"We've had 'em all over, in railroad ties in our backyard, in the front stoop, the attic," said Beth Lipsteuer of Barrington. A yellow jacket stung her husband, Stuart, while he was pruning a tree and disturbed a nest under the eaves.

BUG BITE INDEX Oooh, that insect bite stings! But exactly how much does it hurt? The Justin O. Schmidt Pain Index, named for the former USDA entomologist who invented it, uses a four-point scale. Following are its ratings for four stinging insects found in the Chicago area, along with Schmidt's observations: 1.0 -- Sweat bee. Light, ephemeral, almost fruity. A tiny spark has singed a single hair on your arm. 2.0 -- Bald-faced hornet. Rich, hearty, slightly crunchy. Similar to getting your hand mashed in a revolving door. 2.0 -- Yellow jacket wasp. Hot and smoky, almost irreverent. Imagine W.C. Fields extinguishing a cigar on your tongue. 3.0 -- Paper wasp. Caustic and burning. Distinctly bitter aftertaste. Like spilling a beaker of hydrochloric acid on a paper cut.

The wasp problem has gotten worse each of the last four years, said Lipsteuer, who called an exterminator twice this summer.

"They just don't go away."

They're doomed

Dave Smith, service manager at Rose Pest Control in Northfield, said August produced "double or triple" the wasp calls he got that month last year.

"This morning, I talked to three different people who were cleaning their gutters and found yellow jackets," he said Wednesday.

At Edward Hospital in Naperville, spokesman Tom Scaletta's search of the hospital's database found 50 hits for the keyword combo "sting, wasp and bee in August '05." That compares with 23 the previous August.

The wasps are crankier now than earlier in the summer, and with good reason, said May Berenbaum, head of entomology at the University of Illinois. Unlike honeybees, which hibernate, cold weather will kill all of the yellow jackets in a hive except the queen.

It's almost as if they know they're doomed, Berenbaum said. As with any social organization in the face of cataclysm, "the hierarchy is breaking down, making them defensive," she said. "They tend to be quite surly and aggressive."

Bees get bad rap

Her U. of I. colleague Philip Nixon can't prove the Chicago area has more yellow jackets this year, but he'd be surprised if it didn't. Another factor, also drought-related, is fewer fungal diseases to kill the wasps and the caterpillars and other soft-bodied insects they feed on.

"There's also plenty of food for them in garbage cans and Dumpsters," Nixon said.

Yellow jackets like picnics as much as people do. Again unlike honeybees, the wasps are meat-eaters and find the smell of cooking burgers or steaks irresistible. They also like sweet, fruity liquids.

"The classic example is the wasp that crawls into a soda can and someone gets stung on the throat," Berenbaum said.

She objects to the bad rap bees get because yellow jackets are mistaken for them. But bees are aggressive "only in defense of the colony," she said.

It's easy to tell the two species apart.

"Bees are fuzzy," Berenbaum said. "Bumblebees are yellow and black, too. But if it's yellow and black and shiny and bald, it's a yellow jacket or a hornet."