Quedius (Microsaurus) indigestus, 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 : 3-7

Quedius (Microsaurus) indigestus sp. nov.

( Figs. 2, 2-1 )

Type material. Holotype ♂, CHINA: Sichuan Province: southwest of Jiulong County, 3890 m, 10–13. VII. 2001, coll. Xiaodong Yu and Hongzhang Zhou (IZ-CAS).

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

BL = 8.9 mm, BW = 1.8 mm, HL/PL/EL = 1.00: 1.26: 1.61, HW/PW/EW/AW = 1.00: 1.33: 1.53: 1.30, HW/ HL = 1.03, HEL/HTL = 1.05, PW/PL = 1.09, EW/EL = 0.98, ESL/EL = 0.57.

Head ( Fig. 2 A) rounded quadrangular, almost as wide as long; eye moderately large, slightly convex, in dorsal view tempora nearly as long as 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 two basal setiferous punctures posteriad of it, situated very close to nuchal constriction, and 1–3 additional setiferous punctures which can be confused with basal punctures mediad or 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–V, XI slightly longer than wide, segments VI–X slightly wider than long.

Pronotum ( Fig. 2 B) slightly 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. 2 C) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 2 C) moderately long, about 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 slightly finer and denser than those of elytra, becoming 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 moderately dilated, sub-bilobed, each heavily covered with tenent setae ventrally, segment II nearly as wide as apex of tibia; tergite VIII with basal ridge complete, nearly straight, with one long seta on each side; sternite VIII ( Fig. 2-1 A) with basal ridge complete, nearly straight, with four long setae on each side, apical margin with a moderately deep and wide medioapical emargination, a small triangular area in front of the emargination impunctate; sternite IX ( Fig. 2-1 B) with basal portion moderately wide and short, subemarginate apically; tergite X ( Fig. 2-1 C) with basal side broadly and moderately deeply concave, apex rounded, slightly protruded; aedeagus elongate, slightly asymmetrical, in lateral view ( Fig. 2-1 D) with apex of paramere not reaching that of median lobe, median lobe with a large tooth-shaped process at apex facing parameral side; aedeagus in parameral view ( Fig. 2-1 E) with paramere slightly curved toward left, nearly parallel-sided, slightly narrower than median lobe, with inconspicuous medioapical emargination; median lobe elongate, with apical 1/3 slightly dilated laterally forming subacute apex ( Figs. 2 E, 2-1G); 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 four sensory peg setae arranged in two groups near apex at each side of apical emargination ( Figs. 2 D, 2-1F).

Female unknown.

Distribution. Quedius indigestus sp. nov. is at present known only from the Gongga mountain range in southern Sichuan Province, at a high altitude of 3890 m. The specimen was collected in an Abies forest using a pitfall trap in July.

Diagnosis. This new species is most similar to Q. antoni Smetana in male genitalia, but it can be distinguished from the latter by having the male sternite VIII with four long setae on each side, paramere of aedeagus asymmetrical, slightly curved toward left; whereas the latter species has the male sternite VIII with three long setae on each side, paramere of aedeagus symmetrical, not curved.

Etymology. The specific name is from the Latin adjective indigestus (disorderly), referring to the variable chaetotaxy of the head.

Figures

FIGURE 2. Quedius (Microsaurus) indigestus 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).