Pachydissus

Medium sized to large, brown or grey beetles with antennae often extending beyond apices of elytra. Frontoclypeus subquadrate. Gland opening at base of mandibles absent. Eyes large, coarsely facetted and distinctly emarginate. Antennal tubercles separated apically. Antennal foramen depressed; anterior margin separated from mandibular articulation. Antennal scape slender, distinctly shorter than pronotum; pedicel transverse; antennomere 3 subequal or longer than scape. Pronotum transverse, lateral margins arcuate and nodulose near middle; pronotal disc rugulose. Prosternal process broad, expanded apically. Procoxal cavities circular without lateral extensions; closed externally. Procoxae not projecting below prosternal process. Mesoventrite flat anteriorly; mesoventral intercoxal process weakly notched apically. Mesocoxal cavities narrowly separated medially, with secondary articulation, broadly open to mesepimeron; mesotrochantin visible. Elytra without striae, elytral punctures not visible; elytral surface without costae, apices bispinose or pointed. Femora and tibiae not flattened.

Pachydissus is a widespread genus with about 40 described species known from Africa, Asia, the Pacific region and Australia. It is widespread in Australia and has been recorded from all states and territories except Tasmania.

Species of Pachydissus are commonly known as the Silvery Brown Longicorns, the larval hosts of these species include Acacia longifolia, A. floribunda, A. dealbata, A. decurrens, A. mearnsii, A. melanoxylon, A. leiocalyx, A. pycnantha, Toona australis, Eucalyptus crebra, E. siderophloia.