In the fall they enter houses to find shelter for the winter and become a nuisance to many homeowners. Control measures include removing host trees, eliminating hiding places, sealing the house and applying insecticide. They are dark brownish-gray to black with distinctive red markings. The wings are folded over each other and lie flat on the back.
Red lines mark the lateral margins of wings and run obliquely across at about midwing.
The young or nymphs of boxelder bugs resemble the adults in shape but are smaller and wingless. Nymphs are solid bright red and develop black markings and wings as they mature. It, too, is found throughout Texas and greatly resembles the boxelder bug in size, shape, and color. This insect is a beautiful bluish to smoky black color and has bright red eyes and stripes along the sides of the head and pronotum. The nymphs somewhat resemble those of boxelder bugs.