Quedius (Microsaurus) postangulus, Cai & Zhao & Zhou, 2015

Quedius (Microsaurus) postangulus View in CoL sp. nov.

( Figs. 8, 8-1 View FIGURE 8 )

Type material. Holotype ♂, CHINA: Sichuan Province: Wolong National Nature Reserve, Wuyipeng, Erdaoping , 2965 m, 30. VII–15. VIII. 2004, coll. Xiaodong Yu. Paratypes: CHINA: Sichuan Province: 1 ♂, Wolong National Nature Reserve, Wuyipeng, Erdaoping , 2965 m, 15–30. VI. 2004, coll. Xiaodong Yu ; 1 ♂, Wolong National Nature Reserve, Wuyipeng, Erdaoping , 2945 m, 15–30. VII. 2004, coll. Xiaodong Yu.

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

BL = 8.3 mm, BW = 1.6 mm, MHWL = 1.6 mm, HL/PL/EL/MHWL = 1.00: 1.31: 1.36: 1.43, HW/PW/EW/ AW = 1.00: 1.27: 1.26: 1.28

Head ( Fig. 8A View FIGURE 8 ) round, wider than long, HW/HL = 1.10; eye large and convex, in dorsal view tempora shorter than length of eye, sharply narrowed posteriad, HEL/HTL = 2.74; posterior frontal setiferous puncture situated slightly before level of posteriomedial margin of eye, separated by distance about equal to diameter of puncture; one smaller setiferous puncture between it and temporal setiferous puncture at posterior margin of eye; temporal setiferous puncture separated from posterior margin of eye by distance a little longer than diameter of puncture, with several small setiferous punctures arranged in an oblique curve behind it; two basal setiferous punctures situated very close to nuchal constriction; head with fine and dense microsculpture of transverse waves and irregular meshes. Antenna relatively long, with segment I longer than segment II or III, segment III slightly longer than segment II, segments IV–VII, XI longer than wide, segments VIII–X about as wide as long.

Pronotum ( Fig. 8B View FIGURE 8 ) slightly wider than long, PW/PL = 1.07, slightly narrowed anteriad, posterolateral and posterior margins continuously and broadly rounded, lateral margins not explanate; three setiferous punctures in each dorsal and sublateral row, last sublateral row puncture situated behind level of large lateral setiferous puncture; surface of pronotum with very fine and dense microsculpture of transverse waves.

Scutellum ( Fig. 8C View FIGURE 8 ) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 8C View FIGURE 8 ) short, about as wide as long, EW/EL = 1.02, ESL/EL = 0.51, slightly broadened posteriad, surface of each elytron covered with dense and coarse setiferous punctures, transverse interspaces between punctures nearly equal to diameter of punctures, surface between punctures without microsculpture.

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 generally becoming so toward apex of abdomen; tergite VII without whitish apical seam of palisade setae.

Male first four segments of fore tarsus moderately dilated, sub-bilobed, each heavily covered with modified pale setae ventrally, segment II as wide as apex of tibia; tergite VIII short, with apical margin nearly truncate, posterior angle distinct, basal ridge complete and nearly straight, with one long seta on each side; sternite VIII ( Fig. 8-1A View FIGURE 8 ) short, with basal ridge complete, slightly arched backward in middle, with four long setae on each side, apical margin with a shallow and moderately wide medioapical emargination, a narrow subacute triangular area in front of the emargination impunctate, apical margin with very long setae curved medially; styli of tergite IX ( Fig. 8-1C View FIGURE 8 ) each with characteristic sclerotized lobe near apex on medial side; sternite IX ( Fig. 8-1B View FIGURE 8 ) with basal portion narrow, surface of apical portion without any seta, only with several short setae and two longer ones on each side along apical margin, apex slightly protruded and pointed in middle; tergite X ( Fig. 8-1D View FIGURE 8 ) in unique shape, with basal side broadly and deeply concave, apical margin widely truncated; aedeagus rather unique, in lateral view ( Fig. 8-1E View FIGURE 8 ), paramere with lateral margins in middle strongly curved and expanded toward median lobe, apex protruding slightly beyond that of median lobe, median lobe with a small hook-shaped process at apex; aedeagus in parameral view ( Fig. 8-1F View FIGURE 8 ) with paramere wide, covering apical half of median lobe, arcuately widened laterally in middle third, apex widely rounded, with a very narrow and deep emargination in middle, hook-shaped process of median lobe fitting into this emargination, median lobe wide at base, gradually narrowed to apical portion forming acute apex, middle third distinctly expanded laterally forming two thin arcuate lobes ( Figs. 8E, F, 8-1H View FIGURE 8 ); apical portion of paramere with two small apical setae at each side of apical emargination, and two similar subapical setae on each lateral side below apex, underside with about 14–19 sensory peg setae arranged in curved transverse group along apical margin at each side of apical emargination ( Figs.8D, 8-1G View FIGURE 8 ).

Female unknown.

Hind wings. Male with hind wings extremely reduced, not functional, MHWL/BL = 0.19. Female not examined.

Distribution. China (Sichuan).

Diagnosis. The male genitalia of this new species are quite unique within euryalus group. It can be distinguished from other species easily by the very long setae along apical margin of male sternite VIII, the sclerotized lobe on styli of male tergite IX, the unique shapes of male sternite IX and male tergite X, and the arcuate lobes on both lateral sides of median lobe.

Etymology. The specific name is derived from the Latin prefix post- (back) and the Latin noun angulus (an angle), referring to the distinct posterior angle of male tergite VIII.