Megasybacodes Kakizoe, Maruyama & Masumoto, new genus

(Figs. 1–5)

Type species. Megasybacodes brevitarsis new species, here designated.

Description. Body (Figs. 1–3) elongate, strongly convex dorsally, color uniformly blackish-brown, matt, generally opaque. Head (Figs. 1–3) large, wide. Clypeus weakly rounded anteriorly, apically pointed and reflexed under head. Clypeocentral disc flat, sparsely punctate-microsetose, punctures weak. Vertex with two pairs of short, longitudinal ridges, densely punctate-microsetose, punctures strong. Genal tips strongly angular in dorsal view, slightly rounded anteriorly, straight posteriorly. Mouthparts small, except for elongate maxillary palpi. Eyes large, visible in dorsal view. Antennae 9-segmented with 3 lamellae, short, amber colored, pubescent. Pronotum (Figs. 1, 3) large and transverse, convex, with six longitudinal carinae, densely inconspicuously punctate-microsetose, inner carinae (paramedian) complete, slightly outwardly sinuate posterior 1/6, adjacent carinae (discolateral) distinctly interrupted anterior 1/4, outer carinae (submarginal) broad, slightly rounded, all carinae extending to anterior and posterior pronotal margin, inner surface of carinae distinctly wrinkled, anterior pronotal margin weakly rounded in dorsal view, lateral pronotal margins strongly protruding horizontally near posterior 1/5. Scutellum (Fig. 1) triangular, notably small, narrow, apically acute. Elytra (Figs. 1, 3) elongate, convex, with four distinctly elevated carinae and eight weak carinae, each topped with rows of inconspicuous setae, interrupted before apex, inner surface of carinae distinctly wrinkled. Macropterous. Mesosternum (Fig. 2) narrow, surface punctate with moderate setae. Metasternum (Fig. 2) slightly convex ventrally, lozenge-shaped, densely punctate-microsetose, distinctly grooved along midline. Abdomen (Fig. 2) with five visible sternites apparently fused, densely punctatemicrosetose, first four narrow, wider laterally, apical sternite (anal sternite) notably broad, approximately as long as sum of first four sternites length in middle. Legs (Figs. 1–4) short with broad femora and tibiae. Femora with ventral surface densely punctate-setose. Profemora invisible in dorsal view. Protibiae flattend, broad, gradually widening from base to apex, strongly protruding apically, with a row of setae dorsally. Meso- and metatibiae flattend, broad, dorsal and ventral surface punctate-setose, gradually denser from base to apex. Protarsi pentamerous, short. Meso- and metatarsi pentamerous, short, basal tarsomere notably broad-flattened. All claws slightly weak, symmetric. Epipharynx (Fig. 5) small, vertically long, anterior margin weakly sinuate at middle, adapted mainly for saprophagy. Epitorma broad, pubescent. Pedia glabrous, with lateral elongate spines serially arranged. Chaetoparia short and dense. Acanthoparia short and weak.

Diagnosis. This genus is similar to the genus Sybacodes in general appearance but is easily distinguished. The combination of the following character states diagnoses of Megasybacodes: (1) large species (over 8.0 mm); (2) distinctly broad flattened basal tarsomere of the meso- and metatarsi; (3) broad flattened tibiae; and (4) densely wrinkled pronotal and elytral surfaces.

Etymology. A combination of the Greek word megas (µέγας) meaning “large” and Sybacodes, one of the genus of Rhyparini, in reference to synapomorphies between the two. Gender. Masculine.