Rabigus cuspus Fei & Zhou, 2021

Fei, Xu-Dong & Zhou, Hong-Zhang, 2021, Three new species of Rabigus Mulsant & Rey (Coleoptera, Staphylininae Philonthina) from China, Zootaxa 4996 (1), pp. 126-132 : 127-128

Rabigus cuspus Fei & Zhou , sp. nov.

( Figs. 1A–F )

Type material. Holotype: ♂, China: Sichuan: Baoxing, Fengtongzhai National Nature Reserve , 1600 m, 17.VIII.2003, collected by Zhao Caiyun ( IZ-CAS).

Description. Measurements: BL= 4.77 mm (HPL= 1.70 mm); HL= 0.79 mm, HW= 0.66 mm (HW: HL= 0.83); ELL= 0.22 mm; TL= 0.36 mm; PL= 0.90 mm, PW= 0.68 mm (PW: HW= 1.03); EL= 1.02 mm, EW= 0.86 mm; AW= 0.9 mm.

Head, pronotum and elytra black, pronotum paler than elytra; maxillary and labial palpi dark reddish-brown; antennomeres I–III dark reddish-brown, antennomeres IV–XI brownish-yellow becoming paler apically; legs brownish-yellow. Abdomen black, shining.

Head narrow, oval, gradually narrowing towards base, hind angles entirely obliterated, slightly narrower than pronotum. Eyes moderate and flat, about 0.61 times as long as tempora; dorsal surface of head with sparse setifer- ous punctures and fine microsculpture. Antenna fairly long, antennomeres II–III subequal in length, antennomeres VIII–X gradually becoming shorter, slightly wider than long, antennomere XI shorter than two preceding segments combined.

Pronotum oval, elongate, 1.32 times as long as wide, slightly convex, almost parallel-sided, dorsal rows on pronotum each with 1+5 large punctures, with fine microsculpture of specialized long lines.

Elytra 1.18 times as long as wide, 1.13 times as long and 1.26 times as wide as pronotum, densely and finely punctures, pubescence fine, surface between punctures without microsculpture. Scutellum small, triangular, with setiferous punctures.

Abdomen wide, very gradually narrowing towards apex; setiferous punctures on abdominal tergites similar to that on elytra, but denser and somewhat finer, surface between punctures without microsculpture.

Male: Parts of sternite VIII and sternite IX damaged. Sternite IX longer and slender, with slightly asymmetrical basal portion, apex deeply emarginate ( Fig. 1F ). Tergite X simple, trapezoid shape, almost truncate and with slight emargination at apex ( Fig. 1E ). Genital segment with styli of tergite IX simple, dense setae apically ( Fig. 1D ).

Aedeagus ( Figs. 1B–C ) narrow and elongate, median lobe in ventral view rather suddenly narrowed, apical portion with acute apex; paramere as in Fig. 1B , apex of paramere with the broadest portion almost as broad as median lobe, with three large and one small sensory peg setae near the petiolar-angle in lateral view.

Remarks. Rabigus cuspus Fei & Zhou , sp. nov. is similar to Rabigus ladakhensis Coiffait, 1982 and Rabigus pulloides Coiffait, 1982 , but differs from two latter species by the number of sensory peg setae: the new species has only three large ones and one small. It is thus easy to distinguish them.

Female. Unknown.

Etymology. The specific epithet is derived from the Latin word cusp - (pointed), refers to the sharp apex of the median lobe and the paramere.

Distribution. China (Sichuan).

Figures

FIGURE 1. Rabigus cuspus Fei & Zhou, sp. nov. A. Habitus; B. aedeagus, ventral view; C. aedeagus, lateral view; D. stylus of tergite IX of male; E. tergite X of male; F. sternite IX of male. Scale bars: A = 1 mm, B–F = 0.2 mm.