Quedius (Microsaurus) rectus, Cai, Yan-Peng, Zhao, Zong-Yi & Zhou, Hong-Zhang, 2015

Cai, Yan-Peng, Zhao, Zong-Yi & Zhou, Hong-Zhang, 2015, Taxonomy of the Quedius mukuensis group (Coleoptera: Staphylinidae: Staphylinini: Quediina) with descriptions of four new species from China, Zootaxa 4013, pp. 1-26 : 14-17

Quedius (Microsaurus) rectus sp. nov.

( Figs. 5, 5-1 )

Type material. Holotype ♂, CHINA: Sichuan Province: Kangding County, Mugecuo, 3800 m, 23. V. 2009, coll. Yulingzi Zhou (IZ-CAS). Paratypes: CHINA: Sichuan Province: 1 ♂, same data as holotype.

Description. Head black; pronotum blackish brown, with margins vaguely and narrowly paler, scutellum dark brown, elytra dark brown, with suture and posterior margin paler; abdomen blackish brown, each tergite with posterior margin narrowly paler; antennae and labrum dark brown, mandibles dark reddish brown, maxillary and labial palpi dark brown; legs dark brown, with tibiae blackish.

BL = 7.7 mm, BW = 1.8 mm, HL/PL/EL = 1.00: 1.27: 1.64, HW/PW/EW/AW = 1.00: 1.34: 1.58: 1.11, HW/ HL = 1.04, HEL/HTL = 0.88, PW/PL = 1.10, EW/EL = 1.00, ESL/EL = 0.60.

Head ( Fig. 5 A) rounded quadrangular, almost as wide as long; eye relatively small, slightly convex, in dorsal view tempora slightly longer than length of eye, gradually narrowed posteriad; no additional setiferous puncture between anterior frontal setiferous puncture and posterior frontal setiferous puncture; posterior frontal setiferous puncture situated distinctly behind level of posteriomedial margin of eye, closer to posteriomedial margin of eye than to nuchal constriction of head, with one additional setiferous puncture at posterior margin of eye before it, with 1–2 basal setiferous punctures posteriad of it, situated close to nuchal constriction, and 1–3 additional setiferous punctures which cannot be confused with basal punctures posteriomediad of it; temporal setiferous puncture situated distinctly closer to nuchal constriction than to posterior margin of eye, with several small setiferous punctures arranged in an oblique group around it; head with fine and dense microsculpture of transverse waves and meshes. Antenna moderately long with segment I longer than segment II or III, segment III longer than segment II, segments IV–VI, XI slightly longer than wide, segments VII–X slightly wider than long.

Pronotum ( Fig. 5 B) wider than long, narrowed anteriad, posteriolateral and posterior margins continuously rounded, lateral margins not explanate; three setiferous punctures in each dorsal and sublateral row, one smaller additional setiferous puncture between each dorsal and sublateral row, last sublateral row puncture situated behind level of large lateral setiferous puncture; one smaller additional setiferous puncture slightly anteriomediad of each large lateral puncture; surface of pronotum with very fine and dense microsculpture of transverse and oblique waves.

Scutellum ( Fig. 5 C) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 5 C) moderately long, as wide as long, slightly broadened posteriad, surface of each elytron covered with dense and coarse setiferous punctures, transverse interspaces between punctures slightly larger than diameter of puncture, surface between punctures without microsculpture. Wings fully developed.

Abdominal tergite II impunctate; setiferous punctures of other tergites becoming slightly sparser toward posterior margin of each tergite, and in general toward apex of abdomen; tergite VII with whitish apical seam of palisade setae.

Male with first four segments of fore tarsus strongly dilated, sub-bilobed, each heavily covered with tenent setae ventrally, segment II slightly wider than apex of tibia; tergite VIII with basal ridge complete, nearly straight, surface without any long seta; sternite VIII ( Fig. 5-1 A) with basal ridge complete, slightly sinuate, with four long setae on each side, apical margin with a wide and moderately deep medioapical emargination, a very small area in front of the emargination impunctate; sternite IX ( Fig. 5-1 B) with basal portion wide and short, with apex subtruncate; tergite X ( Fig. 5-1 C) with basal side broadly and shallowly concave, apex widely arcuate; aedeagus in lateral view ( Fig. 5-1 D) with apex of paramere not quite reaching that of median lobe, median lobe with a large tooth-shaped process at apex facing parameral side; aedeagus in parameral view ( Fig. 5-1 E) with paramere straight, parallel-sided, with shallow medioapical emargination; median lobe slightly asymmetrical, with apical 1/3 vaguely dilated laterally forming narrowly arcuate apex ( Figs. 5 E, 5-1G); apical portion of paramere with two moderately long apical setae at each side of apical emargination, and two similar subapical setae on each lateral side below apex, underside with five sensory peg setae arranged in two groups near apex at each side of apical emargination ( Figs. 5 D, 5-1F).

Female unknown.

Distribution. Quedius rectus sp. nov. is at present known only from the Gongga mountain range in central Sichuan Province, at a high altitude of 3800 m. The specimens were collected in a Rhododendron forest in May. Diagnosis. This new species is a little similar to Q. tzwu Smetana in male genitalia structure, it can be distinguished from the latter by having the male sternite VIII with four long setae on each side, the paramere of aedeagus straight, parallel-sided, relatively wider; whereas the latter species has the male sternite VIII with three long setae on each side, the paramere of aedeagus only subparallel-sided, and relatively narrower. Etymology. The specific name is from the Latin adjective rectus (straight), referring to the parallel-sided paramere of the male aedeagus.

Figures

FIGURE 5. Quedius (Microsaurus) rectus sp. nov.: A. head (1.0 mm); B. pronotum (1.0 mm); C. elytra (1.0 mm); D. underside of paramere (0.2 mm); E. apical portion of median lobe, parameral view (0.2 mm). (Scale in parentheses).