Box elder bugs become nuisance pests as they move into buildings.  Problems are most severe along south and west sides of structures, since the bugs tend to move into cracks and crevices in the sun warmed areas.

​Adult box elder bugs are about 1/2" inch in length, dark brown or black, with conspicuous red markings.  Immature box elder bugs are smaller and a solid bright red color.  Only the adults are capable of overwintering successfully.

​The box elder tree seeds, produced on female box elder trees, are the food of the 2nd generation.  The severity of box elder bugs as nuisance pests is correlated with such factors as in the amount of seeds produced the previous year, nearness of female box elder trees, and length of the growing season. 

​When inside a building, box elder bugs are in a semi-dormant state.  They cannot reproduce and do not feed.  Bites on humans are rare, but occasionally occur.