Tom Turpin
Professor of
Purdue University







The Case of the Winter Wasp

Everybody knows that winter is a time when insects are scarce. You see, winter is that season when temperatures turn downward. Cold temperatures and insects don't mix.

Being cold-blooded, the insects can't function when it's cold. We still have our housemates, like cockroaches, fleas and flies, that have come to live in our homes and on our pets. These do quite well during the winter months! But most insects disappear.

Enter the winter wasp. The wasp, that armed warrior of the insect world and flying, poison-loaded hypodermic needle. The wasp, that uninvited purveyor of terror for every man, woman, and child within striking distance.

Everybody knows that wasps aren't to be about in winter! Except for a few wasps. Because, for example, there was a wasp in our kitchen the day after Christmas. My daughter vociferously called it to my attention. And what winter churchgoer hasn't been a witness to the quiet hysteria of the congregation that is created by the menacing mid-winter flight of a wasp. Such wasps always seem to gain attention by losing significant amount of altitude right over "Amen" pews.

This wasp, out of place, is a quirk of wasp biology brought about by heated buildings, churches, houses and the like. In the fall, with the approach of winter, many female wasps mate and head to sheltered locations to hibernate for the winter. A typical natural location for hibernation would be in the leaf litter of the forest floor, where a wasp would settle down for a long winter's nap.

With the coming of spring, the rays of the sun warm the forest floor. The warmer temperatures signal to the slumbering wasp that it's time to venture from the hibernation location. She heads on her way with the mission of beginning a new nest for the coming season.

But in permanent buildings, such as houses, churches and schools, the lady-in-waiting wasp has a new place to spend the winter. However, buildings, which are unnaturally warm to insects during the cold months, cause some problems. The wasp that has crawled into the inner crevices of an attic, eave or windowsill to slumber is exposed to the heat from the interior of the building. Consequently, she does the perfectly normal thing for a wasp - begins move around in preparation for nest-building and egg-laying. That results in the flight of a winter moth.

The strafing run above the congregation during the sermon on a bright Februrary's Sunday is sure to grab attention. Don't think of that brazen, aerial daredevil as a wasp out of place. Think of her as the first indicator of spring.


Writer: Tom Turpin
Editor: Steve Cain