Habits and Characteristics of Box Elder Bugs

Box Elder bugs are more of a nuisance than a hazard. Measuring about 1/2 inch long, these bugs are identified by their coloring and markings, They are either black with orange or red with a distinct X created when their wings are folded against their back. The nymphs are red, and are about 1/16 inch long.


Box Elder bugs typically become active in warm springs, and can be found primarily around female Box Elder trees, but also can be found around various other plants. They breed and lay eggs on the trunks of trees. They do not damage the plants or trees, and eat mostly seeds on the ground. In late summer, they will collect on the exterior of buildings, and as the weather cools, they will try to get into homes and buildings seeking refuge and preparing for the cold weather.


Box Elder bugs only become a nuisance when they attempt to enter homes. Drapes, curtains and walls can become stained with their excrement. Once inside a home they tend to collect in out-of-the-way warm areas, such as an attic. They can best be controlled by preventing access to the building with good weatherization and sealing of cracks.