Boxelder Bugs

For most people, the boxelder bug needs no introduction. This insect is about one-half inch long as an adult, black in color with three red lines behind the head, a red line along each side and a diagonal line on each wing. Boxelder bugs become a nuisance in and around homes from fall through early spring. Boxelder bugs feed on a variety of plants, but their favorite food is boxelder seed pods, which are found only on the female boxelder tree. These insects seldom develop in sufficient numbers to be a nuisance unless a female boxelder tree is in the neighborhood.

The boxelder bug overwinters as an adult in protected places such as houses and other buildings, cracks or crevices in walls, doors, under windows, and around foundations--particularly on south and west exposures. In the spring, small red eggs are laid on leaves and stones, and in cracks and crevices in the bark of female boxelder trees. The eggs later hatch into young nymphs that are wingless and bright red in color wtih some black markings. These young bugs usually are found on low vegetation near boxelder trees until seeds are formed on the tree that they then start to feed on.

Boxelder bugs are primarily a nuisance pest, annoying residents by crawling on exteriors and inside dwellings on warm fall and winter days. They also could stain draperies and other light-colored surfaces and produce an unpleasant odor when crushed. They do not bite people, nor will they damage houseplants.

The most permanent solution to the boxelder bug problem would be complete removal of female boxelder trees from a neighborhood, although this may not be practical or desirable. Since boxelder bugs usually overwinter near the trees they feed on, the removal of one or two problem trees may be of benefit to the homeowner. Infested trees may be sprayed with an insecticide listed for this use while the bugs are still concentrated on the trees, before they move into the house.

When the bugs begin to congregate on dwelling exteriors, these areas may be treated with a residual insecticide listed for this type of control. (Make sure you read the insecticide label carefully and always test a hidden area to make sure the product doesn't stain).

Screening or sealing cracks or other entrances into the home (in the fall BEFORE it gets cold) is important because once boxelder bugs have entered the home, control becomes more difficult. A vacuum cleaner is useful for controlling bugs that have entered the house. This is temporary relief because the boxelder bugs may continue to enter the move about on warmer days throughout the fall, winter and early spring.

This article was written by Mary Jane Frogge, Extension Associate and it appeared in the NEBLINE Newsletter. The information was updated November 2015 by Soni Cochran, Extension Associate.

For information on reproducing this article or using any photographs or graphics, read the Terms of Use statement

Nebraska Extension in Lancaster County is your on-line educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office