Neosternus hisamatsui (Nakane, 1982) Nakane, 1982

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 : 99-102

Neosternus hisamatsui (Nakane, 1982) comb. n. Figs 36-37, 39, 44, 49, 54, 57-58, 69-72

Microsternus hisamatsui Nakane, 1982

Material examined.

CHINA: CHINA: Guangxi Prov.: 3♂♂, 2♀♀, Shangsi County, Mt. Shiwandashan, 21°54'N, 107°53'E, alt. 300-500 m, 25.IV.2011, PENG, ZHAI & ZHU leg. (SNUC); 1♂, Shangsi County, Mt. Shiwandashan, 21°54'N, 107°53'E, alt. 300-500 m, 4.V.2011, Liang Tang leg. (SNUC)

Description.

Body (Figs 36, 37) elongate oval, length: 2.4-3.0 mm; width: 1.2-1.4 mm. Head and elytra reddish-brown; pronotum general reddish-brown; legs, palpi and base of antennae reddish-brown. Each elytron with two to four black bands.

Head width between eyes = 8 times eye diameter in dorsal view; punctation coarse, sparse, separated by 3-4 puncture diameters; epistome truncate, lacking marginal line on anterior margin; stridulatory files not evident. Eyes coarsely facetted. Antennomere III about 1.8 times as long as IV; antennomere VIII slightly wider than VII, about 1.2 times as wide as long; antennomere IX trapezoidal; antennomere X transverse; antennomere XI almost elliptic; relative lengths of antennomeres II–XI: 15: 18: 10: 10: 10: 10: 10: 14: 15: 17. Maxillary and labial terminal palpomeres acuminate, sensory area restricted to apex. Mentum broad with anterior projection, almost triangular, slightly more than 3.5 times wider than long.

Pronotum arched, widest at base (pl/pw = 0.55); narrowed from base to apex, with a deep sulcus along each side, which is broadly margined and the bordering gradually widened anteriorly (Fig. 49), which formed thicken lines in lateral view (Fig. 54); disk coarsely and sparsely punctured, except the impunctate medio-basal area, which is limited by an arched transverse row of coarse punctures.

Prosternum (Fig. 39) 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, bearing a few fine punctures; sides rugose, coarsely and densely punctured. Mesosternum almost conceled by prosternal process, impunctate as the mesepisterna, which is somewhat concave. Metasternum rather sparsely and strongly punctured on lateral areas, some finer punctures on median area, with a pair of mesocoxal lines strongly divergent posteriorly. Abdomen rather strongly and closely punctured, but median areas of four basal visible sternites and medio-basal area of last visible sternite with few punctures respectively; without metacoxal lines on basal visible sternite. Legs rather robust.

Scutellum pentagonal, with each corner rounded, flattish and almost impunctate on surface.

Elytra strongly convex, with eight striae of distinct punctures on each elytron and each interstice with a row of extremely fine punctures.

Male genitalia (Fig. 69) with flagellum (Figs 57-58) curved, bearing a dorsal, arched, cartilaginous mass on apical quarter; flagellar apex acute with a well-separated ventral process; dorsal lobe (Fig. 70) of internal sac with separated front and triangular end; ventral lobe of internal sac trident-like.

Female genitalia (Fig. 72) and spermatheca (Fig. 71) simple.

Distribution.

China, Japan.

Diagnosis.

Characterized by its small body and entirely reddish-brown pronotum.

Comment.

Neosternus hisamatsui Nakane is similar to Neosternus higonius Lewis in the form and color pattern of the body. Neosternus hisamatsui can be distinguished from Neosternus higonius by the pronotum entirely reddish-brown. Neosternus higonius has pronotum black with reddish-brown sides. Though the male genitalia and dorsal lobe of internal sac of Neosternus higonius is similar to Neosternus hisamatsui , with only one specimen of Neosternus higonius available and no Japanese specimens, we can’t consider Neosternus hisamatsui as a synonym of Neosternus higonius . This should be considered after maor materials are available for study.