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

Like other species of the tribe Xyleborini, the head of X. crassiusculus is completely hidden by the pronotum in dorsal view, the antennal club appears obliquely cut, and the body is generally smooth and shining. Xylosandrus spp. are distinguished from related genera by the stout body, truncate elytral declivity, and non-contiguous procoxae.