Quedius (Distichalius) paululus, Cai, Yan-Peng & Zhou, Hong-Zhang, 2015

Cai, Yan-Peng & Zhou, Hong-Zhang, 2015, Three new species of Quedius elpenor group (Coleoptera: Staphylinidae: Staphylinini: Quediina) from China, Zootaxa 3947 (2), pp. 236-250 : 245-249

Quedius (Distichalius) paululus sp. nov.

( Figs. 4, 4-1 )

Type material. Holotype ♂, CHINA: Sichuan Province: Baoxing County, Guobayan, 3270 m, 1–4. VII. 2001, coll. Xiaodong Yu, Hongzhang Zhou.

Description. Head black, pronotum dark brown, both strongly iridescent; scutellum and elytra dark brown; abdomen entirely dark brown; antennae and mouth part dark brown; legs dark brown, tibiae blackish.

BL = 7.8 mm, BW = 1.8 mm, HL/PL/EL = 1.00: 1.38: 1.80, HW/PW/EW/AW = 1.00: 1.34: 1.57: 1.39

Head ( Fig. 4 A) round, wider than long, HW/HL = 1.15; eye large and convex, in dorsal view tempora shorter than length of eye, sharply narrowed posteriad, HEL/HTL = 2.24; two additional setiferous punctures between anterior frontal setiferous punctures; posterior frontal setiferous puncture situated distinctly behind the level of posteriomedial margin of eye, separated by distance longer than diameter of puncture; one smaller setiferous puncture between it and temporal setiferous puncture at posterior margin of eye; temporal setiferous puncture situated slightly closer to posterior margin of eye than to nuchal constriction, with several small setiferous punctures arranged in an oblique curve behind it; two basal setiferous punctures situated very close to nuchal constriction; head with very fine and dense microsculpture of transverse waves and irregular meshes. Antenna robust, with segment I longer than segment II or III, segment III distinctly longer than segment II, segments IV–VI, XI slightly longer than wide, segments VII–X slightly wider than long.

Pronotum ( Fig. 4 B) wider than long, PW/PL = 1.11, slightly narrowed anteriad, posterolateral and posterior margins continuously and broadly rounded, lateral margins not explanate; three setiferous punctures in each dorsal and sublateral row, one extra setiferous puncture between each dorsal and sublateral row, last sublateral row puncture situated behind level of large lateral setiferous puncture; surface of pronotum with microsculpture similar to that of head, but even finer.

Scutellum ( Fig. 4 C) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 4 C) relatively long, as wide as long, EW/EL = 1.00, ESL/EL = 0.57, slightly broadened posteriad, each elytron with surface evenly covered with moderately dense and coarse setiferous punctures, transverse interspaces between punctures about twice as wide as diameter of punctures, surface between punctures with microsculpture of dense microscopic punctulation. Wings fully developed.

Abdominal tergite II impunctate; setiferous punctures of other tergites much finer and denser than those of elytra, almost evenly distributed on each tergite; tergite VII with whitish apical seam of palisade setae.

Male first four segments of fore tarsus strongly dilated, sub-bilobed, each heavily covered with modified pale setae ventrally, segment II slightly wider than apex of tibia; sternite VII with a very inconspicuous medioapical emargination at apical margin, a very small triangular area around the emargination impunctate; tergite VIII with basal ridge complete, nearly straight, without any long seta; sternite VIII ( Fig. 4-1 A) with basal ridge very vague, with two long setae on each side, apical margin with a deep and wide medioapical emargination, a relatively large acute triangular area in front of the emargination impunctate; sternite IX ( Fig. 4-1 B) with basal portion wide and short, with two slightly differentiated setae on each side of apical margin; tergite X ( Fig. 4-1 C) with basal side broadly and shallowly concave, apical margin widely rounded; aedeagus in lateral view ( Fig. 4-1 D) with apex of paramere not quite reaching that of median lobe, median lobe with apical 1/4 distinctly attenuate and curved toward paramere, with a short median carina at apex pointing toward paramere side; aedeagus in parameral view ( Fig. 4- 1 E) with paramere moderately narrowed laterally at basal 1/4, and then gradually widened to apical 1/4, apical 1/4 gradually narrowed forming subtriangular apex, lateral margins thinned and widely expanded; median lobe wide at base, then evenly narrowed to acute apex ( Figs. 4 E, 4-1G); apical portion of paramere with two apical setae clustered at middle and three subapical setae on each side, underside with 19 very small sensory peg setae arranged in two longitudinal groups along sides ( Figs. 4 D, 4-1F).

Female unknown.

Distribution. China (Sichuan).

Diagnosis. This new species and Q. (Distichalius) numa Smetana are slightly similar in male genitalia by having aedeagus in relatively similar shape and sensory peg setae on underside of paramere in small size, but they can be distinguished by the new species having paramere relatively wider in apical half, distinctly covering apical portion of median lobe except for apex, lateral margins thinned and expanded, and median lobe evenly narrowed to acute apex; whereas Q. (Distichalius) numa Smetana has paramere relatively narrower in apical half, barely covering apical portion of median lobe, lateral margins not thinned or expanded, and median lobe suddenly narrowed into rod-like, acute apex.

Etymology. The specific name is from Latin adjective paululus (very small), referring to the small size of the sensory peg setae on underside of paramere.

Figures

FIGURE 4. Quedius (Distichalius) paululus 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 lengths in parentheses)