OCTOBER
1993

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

10-28-93

Bugs on the Wall

On warm, sunny fall days, many homeowners come eye to eye with ladybugs. On such days, these insects can sometimes be found crawling in high numbers on south walls of many buildings. And some even manage to find their way into our domiciles.

To most people, ladybugs are desirable insects. These brightly colored, black-spotted beetles feed on such pest insects as scales and aphids. Because of this good-bug-eat-bad-bug behavior, most gardeners and farmers have a warm spot in their hearts for the ladybug. However, even this loving relationship can turn sour when the insect shows up on a sofa or kitchen curtain.

Ladybugs are one of the insects that hibernate during winter months. They seek sheltered sites for their off-season snooze — a well-deserved rest from a helter-skelter summer spent on an aphid search-and-destroy mission.

In the more tropical parts of the world such as California, ladybugs fly off to the mountains for the winter. Sometimes they fly as many as 15 miles seeking an overwintering site. The lower temperatures of the higher elevations keep the ladybugs cool until there are insects available for them to eat in the next growing season. Ladybugs congregate in leaf litter and under rocks, where they can be found by the millions during their dormant periods.

In temperate regions, where seasonal low temperatures definitely keep the ladybugs cool during the winter, it isn't necessary for them to move as far to find an overwintering site. They just head to the nearest leaf pile, rock, haystack, or house and crawl in for the next three or four months.

That's when we find them crawling in the kitchen sink. Of course, most homeowners find any insect to be undesirable when it has gall enough to intrude in our territory. Most people try to get rid of the uninvited guest even though it probably played an important role in controlling aphids on garden or ornamental plants.

The best thing to do is carry the ladybugs outside and hope temperatures stay low enough so they don't crawl around again until springtime. Some homeowners ought to be happy that they have ladybugs, especially those that purchase them from biological control houses to release each spring.

Even if you're not an avid gardener, don't be too hasty in getting rid of the ladybugs. After all, an old saying holds that having a ladybug in the house will bring good luck. If one brings good luck, who knows what two — or a dozen — might bring!

 

Writer: Tom Turpin
Editor: Andrea McCann