Belonuchus obvelatus, Li & Zhou, 2010

Li, Liang & Zhou, Hong-Zhang, 2010, Revision of the Chinese species of the genus Belonuchus Nordmann (Coleoptera: Staphylinidae: Philonthina), Journal of Natural History 44 (35 - 36), pp. 2149-2177 : 2161-2163

Belonuchus obvelatus sp. nov.

( Figure 6A–C )

Type material

Holotype: male, Indonesia: Sumatra: Mjöberg, Belonuchus grandiceps ( Kraatz, 1859) (identified by Bernhauer), Chicago NHMus, M. Bernhauer Collection ( FMNH) . Paratype: male, Indonesia: Java, Bowring 63.47*, Belonuchus grandiceps ( Kraatz, 1859) (identified by Bernhauer), Chicago NHMus, M. Bernhauer Collection ( FMNH) .

Description

Head and neck black. Pronotum, scutellum and elytra reddish-brown. Antennae dark brown with antennomeres I–III entirely reddish-brown, antennomeres VIII–XI or antennomeres VII–XI reddish-brown. Abdomen black with blue lustre, tergites III–IV entirely reddish-brown, posterior margins of tergites V–VII markedly reddishbrown. Mandibles dark brown. Maxillary and labial palpi and legs reddish-brown.

Body depressed, 10.0– 10.2 mm long (HPL: 3.51–3.67 mm). Head obtusely quadrangular, 1.63–2.04 mm long, 1.80–2.04 mm wide, slightly wider than long (HW: HL = 1.00–1.10), slightly widened posteriad behind eyes, with broadly obtuse hind angles. Frons with slight longitudinal median impression and four punctures placed in square. Tempora 0.73–0.90 mm long, sparsely and coarsely punctate; eyes moderately large, slightly prominent, 0.57 mm long, 0.64–0.78 times as long as tempora. Lateral portions of head with distinctly sparser punctures than that of B. grandiceps ; vertex largely impunctate; entire head with distinct and profound microsculpture of transverse waves. Antennae short, antennomere I very long, thickened towards apex, antennomere III distinctly longer than antennomere II, antennomere IV almost as long as wide, antennomeres V–X distinctly transverse, antennomere XI slightly longer than wide, obliquely truncate.

Pronotum slightly narrowed posteriad, lateral margin usually distinctly concave in posterior half; 1.63–1.80 mm long, 1.63–1.80 mm wide, slightly narrower than head (PW: HW = 0.88–0.91); dorsal rows each with five or six punctures, lateral portions each with four or five large punctures; microsculpture fine, similar to that on head.

Elytra slightly widened posteriad, 2.20–2.28 mm long, 2.20–2.45 mm wide, 1.23–1.40 times as long as pronotum, sparsely and finely punctate, punctures separated by two to three times their diameter. Scutellum large, triangular, densely and finely punctate.

Abdomen slightly narrowed posteriad, widest 1.88 mm, finely and closely punctate, punctures separated by two to three times their diameter at base, gradually becoming sparser toward apex of each tergite; surface between punctures with exceedingly fine and dense microsculpture of transverse striae; first three visible abdominal tergites with two basal lines, elevated area between basal lines with one or two more or less irregular rows of fine punctures.

Male. Anterior tarsomeres I–IV dilated, with modified pale setae ventrally. Sternite VIII with inconspicuous, medio-apical emargination. Genital segments with styli of tergite IX simple, moderately setose apically. Sternite IX with markedly asymmetrical proximal portion, slightly emarginate apically. Tergite X triangular, subtruncate at apex, with numerous apical setae.

Aedeagus slender ( Figure 6A–B ), median lobe distinctly narrower than that of B. grandiceps , distinctly exceeding paramere, subrounded apically; in lateral view, median lobe without subapical tooth; paramere short, distinctly narrower than median lobe, face adjacent to median lobe with five sensory peg setae, arranged along medial-apical portion of paramere ( Figure 6C ).

Female. Unknown.

Etymology

The specific name is from Latin word obvelatus (meaning “hidden”).

Distribution

At present known only from Indonesia (Sumatra, Java) .

Remarks

Bernhauer (1928) reported B. grandiceps ( Kraatz, 1859) from Sumatra and Java, Indonesia. We examined the specimens of B. grandiceps identified by Bernhauer (FMNH). These specimens are not B. grandiceps but a new species B. obvelatus sp. nov. Belonuchus obvelatus sp. nov. can be easily distinguished from B. grandiceps by sparser punctures on head, tergites III–IV entirely reddish-brown, posterior margins of tergites V–VI markedly reddish-brown and distinctly narrower aedeagus. This new species is described in this paper to conveniently compare it with the species B. grandiceps (distributed in China).

Figures

Figure 6. Belonuchus obvelatus sp. nov. (A) Aedeagus, ventral view; (B) median lobe of aedeagus, lateral view; (C) underside of paramere. Belonuchus grandiceps (Kraatz, 1859); (D) tergite X of female; (E) sternite IX of male; (F) tergite X of male; (G) aedeagus, ventral view; (H) median lobe of aedeagus, lateral view; (I, J) underside of paramere; (K) sternite VIII of male. Scale bars 0.5 mm.