Dorsal (top) and lateral (bottom) views of a male Xylossandrus crassiusculus (Motschulsky), commonly called the "Asian ambrosia beetle." The white line in each photograph represents 1.0 mm.

Males are about 1.5 mm long, much smaller than females. Their shape is also distinctive, characterized by a radically reduced thorax and a generally "hunch-backed" appearance. Like other species of xyleborines, males are flightless and rarely encountered outside their brood gallery.