Microsternus Lewis, 1887

Dai, Cong-Chao & Zhao, Mei-Jun, 2013, Genus Microsternus Lewis (1887) from China, with description of a new genus Neosternus from Asia (Coleoptera, Erotylidae, Dacnini), ZooKeys 340, pp. 79-106 : 81-83

Genus Microsternus Lewis, 1887 Figs 1-2, 3-6, 7-8, 9-12, 13-14, 15-21, 22-23, 24-29, 30-33, 40-42, 45-47, 50-52, 59-64, 73-74, 77-78

Type species.

Megalodacne ulkei Crotch, 1873

Description.

Body (Figs 1-2, 7-8, 13-14, 22-23, 73-74, 77-78) small, elongate, with legs short and robust, the tarsi cylindrical, 5-jointed, the four basal joints short, nearly equal in size and not at all dilated, the last joint long. Antennae not very long, the latter with a broad 3-jointed club. Eyes coarsely facetted. Head with the pit posterior to the postmandibular lobes (Figs 40-42). Maxillary and labial terminal palpomeres acuminate, sensory area restricted to apex. Pronotum (Figs 45-47) arched, widest at base; narrowed from base to apex, with formed thinned lines in lateral view (Figs 50-52); disk punctured, except the impunctate medio-basal area, which is limited by an arched transverse row of coarse punctures. Prosternum with median area including its process elevated in an elongate triangular plane, which is distinctly bordered by a ridge on both sides and shortly rounded-subtruncate in front. Mesosternum almost concealed by prosternal process. Metasternum with a pair of mesocoxal lines strongly divergent posteriorly. Abdomen without metacoxal lines on basal visible sternite. Elytra convex.

Distribution.

Microsternus is widespread in Asia, with one species in Australia and one species in America.

Diagnosis.

Defining characters for Microsternus are body elongate, head with the pit posterior to the postmandibular lobes, pronotum without a deep sulcus along each side and narrowed margin in lateral view, mesosternum almost concealed by prosternal process, male genitalia with flagellum (Figs 59-64) bearing a straight mass on apical quarter.

Key to Chinese species of genus Microsternus