Tom Turpin
Professor of
Purdue University







Eating Beetles is no Picnic

Let's have a picnic! Eating in the great out-of-doors ranks right up there with swimming and going to the ball game as things to do in the summer. We even have special equipment named for the occasion -- picnic baskets and picnic tables.

You can't have a picnic unless someone shows up with the food. The food attracts not only ants but other insect named especially for the event, the picnic beetle. This uninvited picnic crasher is a black beetle with four yellow dots. It's about the same size as a house fly and is sometimes called a fungus beetle or sap beetle.

These common names all reflect the food habits of the picnic beetle. The insect in both the adult and immature stages feeds on decaying plant material or the fungus that grows in such situations. It commonly can be found around plants that have been damaged. Some entomologists have suggested that the insect may be more common in years when corn is badly damaged by corn borer. The damage to the plants provides breeding sites for the beetles.

In fact, picnics are frequently smorgasbords of damaged and fermenting plant material. Potato salads, cole slaw, cucumbers and relish trays must seem like heaven to hungry picnic beetles. So when these beetles discover our picnic, they drop in for a bite.

These beetles drop in literally. As they fly about seraching for food, the odors from the picnic dishes are a signal that dinner is served. The beetles then fold their wings and fall from the sky. Sometimes they are on target and fall right into the dish of choice -- theirs not ours. Sometimes they crawl around to find it.

Always, their presence is disconcerting to picnic-goers who want to eat outdoors but don't want to share their food with outdoor creatures; or worse et, who shudder at the thought of inadvertently devouring one of the little creatures in a spoonful of potato salad.

It's not easy to keep picnic beetles from crashing a picnic. Some people have been known to place jar lids of beer laced with a dash of insecticide in the vicinity of the picnic-to-be a day prior to the event. The picnic beetles are attracted to the fermented plant sap known as beer and get a dose of insecticide.

Most of us have just learned to live with picnic beetles. We, of course, eat more carefully when they are around. After all, sharing your picnic with an insect is one thing, but eating an insect in your potato salad is, shall we say, "no picnic!"


Writer: Tom Turpin
Editor: Andrea McCann