Home Invaders of the Six-Legged Kind

By Tome TurpinProfessor of Entomology; Purdue University
turpin@purdue.edu

It happens every year about this time. I refer of course to the arrival of fall. It is an appropriately named season. Leaves fall from trees. Football teams fall from the ranks of the unbeaten. Nuts, apples and acorns fall from their nurturing boughs. Petals fall from the last flowers. And temperatures fall from the highs of summer. All of this falling stuff means that winter is on the way.
But there are other signs. Some birds bid our fields and gardens a fond farewell and head south. Other creatures just hunker down for the cold season, a process known as hibernation. These animals generally store up a supply of fat to use as energy during their long winter's nap. Some squirrels build a nest from leaves and twigs for protection from the howling wind and cold. Cold-blooded frogs, toads, salamanders and snakes burrow into the soil for winter insulation.
Insects are also cold blooded, and they don't do winter either. A few insects build winter protection in a squirrel-like fashion. For instance, some giant silkworm moths spin a cocoon for their winter quarters. Other moths wrap themselves in a leaf blanket. In these cases the insect whiles away the days of ice and snow as a pupa inside a winter cover.
Some species of insects are much like frogs and toads because they seek shelter as winter approaches. Insects crawl into piles of leaves, beneath the soil or under the bark of trees. And like some birds a few insects, such as the monarch, migrate to warmer climes for the winter.
Still other insects do a short migration from their summer habitats and seek shelter in our homes. These six-legged home invaders do not receive warm welcomes from the human homeowners. Quite the opposite. We humans look with disdain at any insects brazen enough to try to move into our quarters. So who are these dastardly demons of the insect world?

Asian lady beetle

First, there is the Asian lady beetle. These beetles are sometimes called Halloween beetles because of their orange coloring and propensity to show up around Halloween time. This insect was introduced to the United States because, like all lady beetles, it feeds on pest aphids. Like other species of lady beetles this one also spends the winter in sheltered sites. But it is more likely than other lady beetle species to seek winter protection in our homes, and because of the sometimes-high populations of the insect, it can become a real nuisance.

Asian Lady Beetle


Attic fly

Another home invader is the attic fly, sometimes called a cluster fly. This fly, about the size and color of the well-known housefly, is so-called because it frequently hibernates in the attics of our homes. It can also be found in winter slumber in corners of garages, wall voids and chimney flues.
Paper wasp queens hibernate and will also take up winter residence in unused portions of human dwellings. These social-insect queens spend the winter in hibernation; with the arrival of spring and warmer temperatures they will try to establish a nest under the eves of a house, barn or shed.

Attic Fly

Boxelder bug

A number of true bugs also try to share our domiciles during the months of winter. These include stink bugs, squash bugs and that notorious home invader, the boxelder bug. True bugs are called that because scientists agree that these insects classified in the order Hemiptera are the only insects that are bugs. The name is based on one of the group called the bed bug, but that is another story. The bugs in general produce an odor. That means you can generally use your nose to tell some bugs are hiding in the corner of the garage in the fall.
The marmorated stink bug is another insect that behaves as if our houses were built for the purpose of providing winter sanctuaries for six-legged creatures. This stink bug is becoming more of a pest on fruits in the Eastern part of the United States. In the fall, just like the lady beetles, the paper wasps and the attic flies, this insect tries to move into our homes. And that, my friends, means we homeowners are becoming used to seeing insects marching across the living room wall in the dead of winter.

Boxelder Bug