Boxelder Bug Sightings

Boxelder trees are sometimes planted in landscapes, since they grow quickly, reaching heights of 30 to 50 feet. However, they are prone to attack by boxelder bugs. These bugs feed primarily on the female seed-bearing boxelder trees by sucking sap from the leaves, twigs and developing seeds. They will also feed on other trees such as ash, maple, plum and apple, causing scarring of fruits.
Adult boxelder bugs are ½ inches in length, brownish-black in color with three lengthwise red stripes near their heads. Under their wings, their abdomen is red. The immature boxelder bugs resemble the adults in shape, except they are smaller, wingless and bright red in color.
During the fall months, adults and immature boxelder bugs tend to congregate on the female boxelder trees and then begin migrating to a place to overwinter. Only adults overwinter by moving to hibernation sites either by crawling or flying. These bugs tend to cluster in large numbers on the sides of trees and structures, so they can easily enter structures under windows sills or through open doors or vents. If they do invade structures, their feces can stain curtains, paper and other home furnishings. Also their mouthparts can penetrate human skin, so beware when touching them.
The boxelder bugs that happen to enter indoors, will not live more than a few days indoors, do not breed inside, and are essentially harmless.


Some Options for Control:

Some Non-Chemical Control Options:
Removal of the female boxelder trees from the landscape would decrease this insect’s population.
Eliminate hiding places such as piles of boards, rocks, leaves, grass and other debris close to the house.
Caulk and close openings where boxelder bugs can enter the house such as around light fixtures, doors and windows, utility pipes and air conditioners.
Screen all windows, doors, crawl spaces, roof vents, since boxelder bugs are attracted to light and can fly in through doors and windows.

Some Chemical Control Options:
If you do not wish to remove female boxelder trees from the landscape, then the exposed immature boxelder bugs can be chemically treated in the spring and early summer. Insecticides containing the active ingredients such as neem, pyrethrin, rotenone, cyfluthrin, deltamethrin, esfenvalerate and malathion can be used. Specialized equipment may be required to treat tall trees.

Photo of boxelder bug. Photo by Elizabeth “Wizzie” Brown, Program Specialist-IPM, Texas AgriLife Extension.