Large and very bulky, densely hairy. Tuft of setae on pronotal basis very large, dense. Pronotum produced anteriad, with two denticles.
Similar to bulky Anisandrus or Xylosandrus, but pronotal side not carinate, and procoxae contiguous.
Despite their large size, all three species of Hadrodemius prefer thin branches or twigs.
Latest revision of the genus published by Beaver (2010).
Eyes shallowly emarginate, upper part smaller than lower part. Antennal club approximately circular, conspicuously flattened, type one (truncated, segment 1 covering posterior side). Costate margin of segment 1 of club encircles club, segment 1 covers entire posterior face, or most of posterior face. Segment 2 thin, corneous, visible on anterior side only, or slightly extender to posterior side. Segment 3 absent from posterior side of club. Segment 1 of antennal funicle shorter than pedicel, funicle 4-segmented, scapus regularly thick, or appears long and slender. Frons above epistoma rugged, coarsely punctate. Submentum slightly impressed, shaped as very narrow triangle. Anterior edge of pronotum with two distinct flat denticles protruding anteriad. Pronotum from lateral view rounded and robust (type 5), from dorsal view rounded (type 1). Pronotal disc shining or smoothly alutaceous, with small punctures, always with dense setae, lateral edge of pronotum obliquely costate, posterolateral corners of pronotum angulately produced. Procoxae contiguous, prosternal posterocoxal process short and conical, or flat and inconspicuous. Tuft on pronotal basis associated with mesonotal mycangium present and very conspicuous, setae on elytral bases associated with elytral mycangium absent (setae present, but no different than on of elytral disc). Scutellum reduced, partly visible on anterior slope of elytral bases. Elytral bases straight, with oblique edge. Elytral disc short and convex, with confused punctures. Lateral profile of elytral declivity steep, especially towards apex, dorsal profile of elytral apex rounded. Declivity covered with abundant and long setae. Posterolateral declivital costa ending in 7th interstriae. Declivital surface devoid of tubercles. Protibiae distinctly triangular, slender on upper part, broad and denticulate on lower part. Posterior side of protibia flat, no granules, only setae. Protibial denticles large, distinctly longer than wide, bases of denticles slightly or distinctly enlarged, conical, usually between 6 and 8 protibial denticles present. Large species, robust, around 4.9 mm. Mature specimens uniformly black, brown legs.