Boxelder bugs get their common name because they are often found on boxelder trees. They are native to the western U.S. but can be found throughout the United States or wherever boxelder trees are found. They become a nuisance when they congregate on or enter homes, sheds, and garages in the fall and again when they emerge in the spring.

What do boxelder bugs look like?

Boxelder bugs are black with reddish or orange markings on their back. They look like a somewhat flattened, elongated oval and are about ½-inch long. The nymphs (immature boxelder bugs) look similar to the adults but lack wings and are bright red in color.

What do boxelder bugs eat?

In the early spring, boxelder bugs will feed on fallen boxelder seeds. Once the leaves start to open, they will move to the female boxelder trees or maple trees to feed on the newly developing leaves. They have also been known to occasionally feed on the fruit of plum and apple trees.

They will then try to migrate to nearby buildings, like homes, sheds, and garages to overwinter. They will hide in cracks and crevices in the walls to protect themselves from winter temperatures.

Boxelder bugs are primarily nothing more than a giant nuisance when they invade your home. However, their fecal matter can cause reddish stains on curtains, drapes, clothing, and other materials. When they handled or crushed, they can also produce a strong, foul odor. They are not known to bite, but their mouthparts can puncture skin, causing a slightly irritating red spot similar to a mosquito bite.

Keep boxelder bugs out

To prevent boxelder bugs from invading your home in the fall, repair holes in window and door screens, seal cracks and crevices around the outside of your home, and install door sweeps on all exterior doors. Then apply Ortho® Home Defense® Insect Killer for Indoor & Perimeter around your home's foundation as well as indoors around door and window casings and along baseboards. Always read and follow label instructions.

Control boxelder bugs that make their way inside

To kill boxelder bugs you find in your house, spray them with Ortho® Home Defense® Insect Killer for Indoor & Perimeter following label directions. Then, remove the dead bugs since they may attract carpet beetles that will go on to attack fabrics, stored dry goods, and other natural products in your home. If you can find where the boxelder bugs are gaining access to the living areas of your home, seal the opening to prevent them from crawling in. You can also choose to suck them up with a vacuum cleaner, and then immediately remove and seal the vacuum bag in a plastic bag before disposal to prevent them from escaping.

To prevent boxelder bugs, in early summer, treat boxelder, maple, and other host trees with Ortho® Home Defense® Insect Killer for Lawn & Landscape, following label directions.