Quedius (Distichalius) fusus, 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 : 242-245

Quedius (Distichalius) fusus sp. nov.

( Figs. 3, 3-1 )

Type material. Holotype ♂, CHINA: Beijing City: Mentougou District, Dongling Mountain, 1290–1509 m, 15– 18. IX. 2012, coll. Xiaodong Yu. Paratypes: CHINA: Beijing City: 1 ♂, Mentougou District, Xiaolongmen Forest Park, 1800 m, 7. VIII. 1993, coll. Hongzhang Zhou; 1 ♀, Mentougou District, Xiaolongmen Forest Park, 22. VII. 1997, coll. Haisheng Zhou; 1 ♂, 1 ♀, Mentougou District, Dongling Mountain, 1290–1509 m, 15–18. VII. 2012, coll. Xiaodong Yu; 1 ♀, Mentougou District, Dongling Mountain, 1225 m, 14–17. IX. 2012, coll. Xiaodong Yu.

Description. Head black; pronotum and scutellum dark brown; elytra dark brown, some with humeral angle, suture and posterior margin slightly paler; abdomen dark brown, each tergite with posterior margin distinctly paler; antennae dark brown, with basal half of antennomere II yellowish brown, labrum and mandibles dark reddish brown, maxillary and labial palpi dark brown; legs dark brown, tibiae blackish brown.

BL = 7.5 mm, BW = 1.6 mm, HL/PL/EL = 1.00:1.26:1.50, HW/PW/EW/AW = 1.00:1.25:1.47:1.42

Head ( Fig. 3 A) round, about as wide as long, HW/HL = 1.05; eye moderately large and convex, in dorsal view tempora shorter than length of eye, gradually narrowed posteriad, HEL/HTL = 2.02; two additional setiferous punctures between anterior frontal setiferous punctures; posterior frontal setiferous puncture situated slightly behind the level of posteriomedial margin of eye, separated by distance about twice as long as diameter of puncture; one smaller setiferous puncture between it and temporal setiferous puncture at posterior margin of eye; temporal setiferous puncture situated in midway between posterior margin of eye and nuchal constriction of head, with several small setiferous punctures arranged in an oblique curve 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. Antenna robust, with segment I longer than segment II or III, segment III slightly longer than segment II, segments IV, XI slightly longer than wide, segments V–X slightly wider than long.

Pronotum ( Fig. 3 B) about as wide as long, PW/PL = 1.05, 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 very fine and dense microsculpture of transverse and oblique waves.

Scutellum ( Fig. 3 C) with very fine and dense microsculpture of transverse waves, impunctate.

Elytra ( Fig. 3 C) moderately long, about as wide as long, EW/EL = 1.03, ESL/EL = 0.52, slightly broadened posteriad, each elytron with surface covered with moderately dense and coarse setiferous punctures, transverse interspaces between punctures about twice as wide as diameter of punctures, surface between punctures without microsculpture. Wings fully developed.

Abdominal tergite II impunctate; setiferous punctures of other tergites finer than those of elytra, becoming slightly sparser toward posterior margin of each tergite, and generally becoming slightly so toward apex of abdomen; 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 very inconspicuous medioapical emargination at apical margin, a small acute triangular area in front of the emargination impunctate; tergite VIII with basal ridge complete, nearly straight, with one long seta on each side; sternite VIII ( Fig. 3-1 A) with basal ridge complete, nearly straight, 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. 3- 1 B) with basal portion long and narrow, strongly curved, with a very shallow middle emargination apically; tergite X ( Fig. 3-1 C) with basal side broadly and shallowly concave, apical margin widely rounded; aedeagus in lateral view ( Fig. 3-1 F) with apex of paramere distinctly protruding beyond that of median lobe, median lobe with a minute hook-shaped process at apex and an inconspicuous narrow median carina along midline from subapex to apical 1/4, both pointing toward paramere side; aedeagus in parameral view ( Fig. 3-1 G) with paramere strongly narrowed laterally in middle, with apical half fusiform, rounded at apex, covering apical 1/3 of median lobe; median lobe wide at base, then gradually narrowed to basal 2/3, apical 1/3 nearly parallel-sided, with tiny subacute apex ( Figs. 3 E, 3-1E); apical portion of paramere with four apical setae and two to three subapical setae on each side, underside with numerous sensory peg setae arranged in a longitudinal band along midline ( Figs. 3 D, 3-1D).

Female first four segments of fore tarsus similar to those of male, but less dilated, segment II about as wide as apex of tibia; tergite VIII with basal ridge complete, nearly straight, with one long seta on each side; sternite VIII with basal ridge complete, with two long setae on each side; tergite X ( Fig. 3-1 H) with basal side broadly and shallowly concave, with subtriangular area in middle distinctly raised and strongly pigmented, apical margin rounded.

Distribution. China (Beijing).

Diagnosis. This new species is the only one without microscopic punctulation on elytral surface in elpenor group, but the presence of the small setiferous puncture at posterior margin of eye on head and the extra setiferous puncture between dorsal and sublateral row on pronotum, and the shape of the aedeagus show that it is doubtlessly a member of elpenor group. It can be distinguished from other similar species easily by the unique shape of the fusiform paramere and the distinct banded pattern of sensory peg setae on underside of paramere.

Etymology. The specific name is from Latin noun fusus (a spindle) in apposition, referring to the fusiform apical half of paramere.

Figures

FIGURE 3. Quedius (Distichalius) fusus 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)