Rabigus sagittus 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 : 129-130

Rabigus sagittus Fei & Zhou , sp. nov.

( Figs. 2A–G )

Type material. Holotype: ♂, China: Shanxi: Guandi Mountain, Hengjian Town , 1570 m, 5.VII.2004, collected by Zhao Caiyun ( IZ-CAS) . Paratypes: Shanxi: 1♂, Guandi Mountain, Haojiagou , 1630 m, 14.VII.2004, collected by Zhao Caiyun ( IZ-CAS) ; 1 ♂, Guandi Mountain, Hengjian Town , 1570 m, 5.VII.2004, collected by Zhao Caiyun ( IZ-CAS) ; 1 ♂, Guandi Mountain, Hengjian Town , 1540 m, 6.VII.2004, collected by Zhao Caiyun ( IZ-CAS) .

Description. Measurements: BL= 5.61 mm (HPL= 1.97 mm); HL= 1.03 mm, HW= 0.67 mm (HW: HL= 0.65); ELL= 0.26 mm; TL= 0.38 mm; PL= 0.94 mm, PW= 0.76 mm (PW: HW= 1.14); EL= 1.08 mm, EW= 1.15 mm; AW= 1.01 mm.

Head black, pronotum and elytra dark reddish-brown, pronotum usually slightly paler than elytra, elytra paler toward the apex; maxillary and labial palpi dark brownish-yellow; antennomeres I–III brownish-yellow, antennomeres IV–XI dark reddish-brown and becoming darker toward apex. Abdomen black, shining, posterior margin of tergites III–VII slightly paler, dark reddish-brown; legs brownish-yellow.

Head narrow, oval, gradually narrowing towards base, completely obliterated hind angles, slightly narrower than pronotum. Eyes moderately large and flat, about 0.68 times as long as tempora; dorsal surface of head with sparse setiferous punctures and fine microsculpture of specialized long lines. Antenna fairly long, antennomeres II–III sub-equal in length, antennomeres IV–VII mostly longer than wide, antennomeres VIII–X gradually becoming shorter, slightly wider than long, antennomere XI shorter than two preceding segments combined.

Pronotum oval, elongate, 1. 23 times as long as wide, slightly convex, almost parallel-sided; dorsal rows on pronotum each with 1+5 large punctures, surface shiny, with fine microsculpture of specialized long lines.

Elytra 0.93 times as long as wide, 1.14 times as long and 1.5 times as wide as pronotum, densely and finely punctate, 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, dense and fine, surface between punctures without microsculpture.

Male: Sternite VIII with moderately wide, triangular medioapical emargination at the apex ( Fig. 2F ). Genital segment with styli of tergite IX simple, with dense setae apically ( Fig. 2G ). Sternite IX long and slender, with slightly asymmetrical basal portion, apex deeply emarginate ( Fig. 2E ). Tergite X simple, triangular, almost truncate and with four setae at apex ( Fig. 2D ).

Aedeagus ( Figs. 2B–C ). Median lobe in ventral view rather suddenly narrowed, apical portion with subacute apex, with a distinct process at either side basad of narrowed part; paramere with strongly dilated apical part that is almost as broad as median lobe, with long subparallel constricted portion at midlength, with two large and one small sensory peg setae in the petiolar-angle in lateral view.

Remarks. Rabigus sagittus Fei & Zhou , sp. nov. is similar to R. ruficapillus , but can be distinguished by the sensory peg setae (number, arrangement and location) on the parameral apex. The new species has also a distinct paired process on the median lobe of aedeagus, midway along its length.

Female. Unknown.

Etymology. The specific epithet is derived from the Latin word sagitt - (arrow), and refers to the ‘arrow-shaped’ apical part of the paramere in dorsal view.

Distribution. China (Shanxi).

Figures

FIGURE 2. Rabigus sagittus Fei & Zhou, sp. nov. A. Habitus; B. aedeagus, ventral view; C. aedeagus, lateral view; D. tergite X of male; E. sternite IX of male; F. sternite VIII of male; G. stylus of tergite IX of male. Scale bars: A = 1 mm, B–G = 0.2 mm.