Almost every fall, county extension offices across North Georgia receive questions about the boxelder bug (Boisea trivittatus). Generally not noticed in summer, boxelder bugs often become an issue when they try to move into homes during fall as they search for overwintering sites

Adult boxelder bugs are about 1/2-inch long, black with red markings, including three stripes on the prothorax, the area right behind the head. Their wings lay flat over their bodies, overlapping each other to form an ‘X'. The immatures are 1/16-inch long and bright red when they first hatch. As they grow older and become larger, they are red and black.

Boxelder bugs are primarily a nuisance because they enter homes and other buildings, often in large numbers. Fortunately, they do not bite people and are essentially harmless to property. When abundant, they can stain walls, curtains, and other surfaces with their excrement.

During late summer and fall, boxelder bugs start to leave the trees from where they were feeding to find protected areas for the winter. Although nymphs may be present in the fall, only fully grown adults survive the winter. Adult boxelder bugs typically can fly several blocks, although in some cases they can travel as far as two miles.

Some homes especially are attractive to boxelder bugs, while neighboring buildings may have few. This usually depends upon the amount of sunny exposure a building receives. Boxelder bugs like warm areas and are attracted to buildings with a southern or western exposure. Color does not appear to influence boxelder bugs as they are found on buildings of all hues.

As the weather cools, boxelder bugs push into cracks and spaces around homes. In some cases they end up in the interior of buildings where they are often found around windows. They remain active until it becomes cold, which could continue into winter when the weather is mild. While you may see persistent numbers of these bugs, individuals are short-lived, only surviving for a few days up to a week.

During winter, boxelder bugs generally are inactive. However, on mild, sunny days, boxelder bugs become mobile with the increased temperature. They enter a home's interior from overwintering areas within the home, for example in walls or attics.

The best management of boxelder bugs is prevention. The following steps will help to keep them from entering your home:

Repair or replace damaged window and door screens; screens in roof and soffit vents; and in bathroom and kitchen fans.

Seal areas where cable TV wires, phone lines and other utility wires and pipes, outdoor facets, dryer vents and similar objects enter buildings.

For larger spaces use polyurethane expandable spray foam, copper mesh or other appropriate sealant.

Install door sweeps or thresholds to all exterior entry doors. Install a rubber seal along the bottom of garage doors.

It may be necessary to treat with an insecticide around the exterior of your home, especially if large numbers of boxelder bugs are present. You can treat your own home by using an insecticide labeled for the exterior of buildings.

Common names of active ingredients available to the public include bifenthrin, cyfluthrin, deltamethrin and permethrin.

Billy Skaggs is an agricultural agent and Hall County extension coordinator. Phone: 770-531-6988. Fax: 770-531-3994.