It’s Time for Boxelder Bugs

boxelder bugs

Adult and nymph boxelder bugs (Boisea trivittatus). Photo courtesy of University of Minnesota.

Almost every year around late fall/early winter, this insect appears on the siding and windows of homes and structures.

Barely noticed during summer, as temperatures begin dropping these critters head indoors where it’s warmer.

Primarily a nuisance, as opposed to a pest, the boxelder bug is associated with female boxelder trees (Acer negundo) although it feeds on other maples and ash trees. Many do not realize what a boxelder tree looks like until the insects associated with the tree comes to visit!

The insect, properly identified as Boisea trivittatus, is about a half inch long, black with orange or red markings, and likely to congregate in significant numbers to feed on boxelder trees or warm themselves on walls with southern or western exposures.

While their feeding does little if any damage to trees, their tendency to move into cracks and gaps around windows or other openings becomes unnerving. They also find a way into walls and attics, from whence they find their way into sunny living quarters, often around windows.

They do not bite or harm people or pets, but in large numbers they can stain walls and curtains with their poop. The moisture in houseplants may attract them, but there is little likelihood the bugs will do any damage.

Dealing with the bugs is primarily through preventing them from entering the dwelling in the first place, or using an exterior insecticide as soon as they begin assembling on the outside of buildings.

Prevention includes repairing windows and screens on the sides of buildings, as well as in roof or soffit vents, bathroom and kitchen fans.

Install door sweeps or thresholds to all exterior doors, including rubber seals along the bottom of garage doors.

If insecticides are necessary, spray in a timely fashion in fall when insects begin appearing. Use an insecticide labelled for outdoor use, with active ingredients such as bifenthrin, cyfluthrin, permethrin, or others.

If the problem has moved indoors, remove them with a vacuum or sweep them up and dispose of them. Spraying insecticides indoors is not recommended as those bugs will die in a few days.

By Sallie Lee, Urban Regional Extension Agent, Alabama Cooperative Extension System.  Contact Sallie at

The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce.  Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.

Alabama Extension

The Alabama Cooperative Extension System operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities and answers home-gardeners' questions each week on Birmingham Gardening Today.

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