The bodies of boxelder bugs are black in color and are marked by red lines along the thorax and sides. Their wings are flat and red. Box elder bugs measure between 1/2 and 1/3-inch wide. Box elder bugs inhabit maples and ashes, and seed-bearing box elder trees, in warm seasons. In winter, they can be found in interior areas such as houses. The rust red eggs of the box elder bug are laid on and destroy host trees.