Box Elder Bugs are about 12mm long and are brownish black with red markings on the thorax and wings. The immature stages are colored red with reduced wings. Box Elder Bugs are commonly found on or in the vicinity of trees in the maple family. Box Elders Bugs may form large groups while sunning themselves in areas such as walls or roofs. Box Elders Bugs are especially a problem during the fall, when they enter houses and other structures seeking warmth or a place to overwinter. Also known as the Maple Bug or Manitoba Maple Bug.