Sinodorcadion Gressitt, 1939

Xie, Guang-Lin, Shi, Fu-Ming & Wang, Wen-Kai, 2013, A review of the genus Sinodorcadion Gressitt, 1939 with description of three new species from China (Coleoptera: Cerambycidae: Lamiinae), Zootaxa 3709 (6), pp. 581-590 : 582

The genus Sinodorcadion Gressitt, 1939

Redescription. Body small, generally shorter than 10 mm in length, covered with dense short pubescence. Head, pronotum and elytra densely and closely punctate. Head not retracted, also not broader than anterior margin of pronotum; frons subquadrate with lower margin slightly narrow, bulging; vertex shallowly concave, occiput slightly convex; eye coarsely faceted, inner side deeply emarginate, lower lobe narrow, longer than broad; both maxillary and labial palpi with last segment flattened and broadly truncate apically in male and cylindrical in female; antennomeres cylindrical, non-fringed beneath; antennal tubercles distinctly elevated, broadly separated; scape without cicatrix at apex, shorter than third antennomere, about as long as fourth antennomere. Pronotum wider than long with convex disc and small lateral tubercles. Scutellum small, rounded apically. Elytra connate, long-oval, broader than pronotum; humeri not protruding; apices rounded or slightly oblique-truncate. Hind wings absent. Prosternal process evenly sloped posteriorly, lower than procoxa; mesosternal process broad, not tuberculate; procoxal cavity closed posteriorly, mesocoxal cavity open at side. Legs long, mesotibia with an oblique groove near external apex; claw widely divergent, forming an angle of about 180 degrees.

Male genitalia. Tegmen approximately as long as median loble plus median struts. Lateral lobe thickening inwards at base and becoming thin towards apex, basal edge nearly straight ventrally, apex rounded, outer margin more or less arched, ventral surface clothed with bristle, gradually becoming long towards apex and forming fringed apical edge. Terminal of ringed part converged and broadly extended, with parallel sides. Median lobe plus median struts broad, stout, strongly curved. Internal sac distinctly divided into three parts, basal region furnished with microscopic zonal sclerites, middle region distinctly swelling, with a diverticulum at each side of apical section, apical region gradually tapered towards apex, end with a ejaculatory ampoule and two ejaculatory ducts.

Remarks. This genus closely resembles Sinomimovelleda Chiang, 1963 but differs in humerus not protruding, last segment of maxillary and labial palpi flattened and broadly truncate apically in male. The genus is also similar to Mimovelleda Breuning, 1940 and Dolophrades Bates, 1884 but differ from Mimovelleda in antennomeres not fimbriate beneath and humerus not spinously protruding, and from Dolophrades in scape without cicatrix at apex and humerus not dentate.

Distribution. China (Zhejiang); Malaysia (Kuala Lumpur).

Biology. Little is known about the biology of this genus. On the basis of collection data the adults of this genus appear from May to July in broad-leaved shrubs of East China at the altitude ≥ 1000 m above the sea.

After several collection trips by sweeping nets in West Tianmushan, Qingliangfeng and Fengyangshan in recent years, and placing Malaise traps in different positions in West Tianmushan and Qingliangfeng in the past two years, we only collected several specimens of the genus. It may indicate that the genus is rare and the population of each species is very small.