Box elder bugs generally eat and reproduce on seed-bearing female box elder trees. They are also known to occasionally feed on the male box elder tree or on some ash, maple and fruit trees.
Controlling box elder bugs generally involves removing their primary food source, which is the female box elder tree, and replacing them with male trees. If homeowners wish to keep the female trees, disposing of the fallen seedpods on the ground below the tree can help to dissuade the bugs from taking up residence. Pesticides can also be used to fight an infestation of box elder bugs.