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

Cai, Yan-Peng, Zhao, Zong-Yi & Zhou, Hong-Zhang, 2015, Three new species of the genus Quedius (subgenus Microsaurus) from China (Coleoptera: Staphylinidae: Staphylinini: Quediina), Zootaxa 3973 (3), pp. 567-578 : 568-571

Quedius (Microsaurus) bilobus sp. nov.

( Figs. 1, 1-1 )

Type material. Holotype ♂, CHINA: Sichuan Province: Baoxing County, Mahuanggou, 2800 m, 16. IV. 2007, coll. Hongzhang Zhou.

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

BL = 5.8 mm, BW = 1.4 mm, HL/PL/EL = 1.00: 1.15: 1.59, HW/PW/EW/AW = 1.00: 1.21: 1.43: 1.16.

Head ( Fig. 1 A) round, slightly wider than long, HW/HL = 1.07; eye large and convex, in dorsal view tempora shorter than length of eye, gradually narrowed posteriad, HEL/HTL = 1.74; posterior frontal setiferous puncture about at the same level of posteriomedial margin of eye, separated by distance about twice as long as diameter of puncture; temporal setiferous puncture situated about midway between posterior margin of eye and nuchal constriction of head, with several small setiferous punctures arranged in an oblique curve behind and below it; two basal setiferous punctures situated much closer to nuchal constriction than to posterior frontal setiferous puncture; head with fine and dense microsculpture of transverse waves and irregular meshes, and scattered with very sparse microscopic punctation. Antenna robust, with segment I longer than segment II or III, segment III slightly longer than segment II, segments IV–V, XI slightly longer than wide, segments VI–X wider than long.

Pronotum ( Fig. 1 B) wider than long, PW/PL = 1.12, narrowed anteriad, posteriolateral and posterior margins continuously and broadly rounded, lateral margins not explanate; three setiferous punctures in each dorsal row and two setiferous punctures in each sublateral row, last sublateral row puncture situated slightly before level of large lateral setiferous puncture; surface of pronotum with microsculpture similar to that of head.

Scutellum ( Fig. 1 C) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 1 C) moderately long, about as wide as long, EW/EL = 0.96, ESL/EL = 0.60, slightly broadened posteriad, each elytron with surface covered with dense and coarse setiferous punctures, transverse interspaces between punctures about as wide as diameter of punctures, surface between punctures without microsculpture. Wings fully developed.

Abdominal tergite II impunctate; III with punctures in middle portion sparser than adjacent areas; IV–VII finely punctate, but sparser than those of elytra; VII with whitish apical seam of palisade fringe.

Male with first four segments of foretarsus moderately dilated, sub-bilobed, each heavily covered with tenent setae ventrally, segment II about as wide as apex of tibia; tergite VIII with basal ridge disrupted in middle, surface without long seta; sternite VIII ( Fig. 1-1 A) with basal ridge complete, nearly straight, with two 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. 1-1 B) with basal portion quite long and narrow, apical half asymmetrical, with apex widely rounded; tergite X ( Fig. 1-1 C) with basal side broadly and shallowly concave, apical margin wide, vaguely pointed in middle; aedeagus ( Figs. 1-1 D, E) markedly asymmetrical, with apex of paramere protruding beyond that of median lobe, median lobe divided into two subequally sized lobes at apex ( Figs. 1 E, 1-1G); paramere wide, with apical portion curved to left, with four long apical setae and two shorter subapical setae on each side, underside with numerous sensory peg setae arranged in a W-shaped transverse group far below apex ( Figs. 1 D, 1-1F).

Female unknown.

Distribution. Quedius bilobus sp. nov. is at present known only from the type locality in central Sichuan Province: Baoxing County, Mahuanggou, at the altitude of 2800 m. The specimen was collected by hand near a creek in April.

Diagnosis. This new species belongs to the lineage comprised of Q. szechuanus Bernhauer, 1933 and Q. huenn Smetana, 2002 within the szechuanus group by all having the aedeagus asymmetrical, and the median lobe characteristically divided into two lobes. However, it can be easily distinguished from the others by the characteristic W-shaped pattern of the sensory peg setae on the underside of the paramere.

Etymology. The specific name is derived from the Latin adverb bis (twice) and the Latin noun lobus (lobe) in apposition, referring to the two lobes on the apical portion of the median lobe of the aedeagus.

Figures

FIGURE 1. Quedius (Microsaurus) bilobus 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).