Tasgius (Tasgius) venustus, Smetana, 2010

Smetana, Aleš, 2010, Contributions to the knowledge of the ‘ Staphylinus-complex’ of China (Coleoptera: Staphylinidae: Staphylinini). Part 22. The genus Tasgius Stephens, 1829, Section 1, Acta Entomologica Musei Nationalis Pragae 50 (1), pp. 145-155 : 153-154

Tasgius (Tasgius) venustus sp. nov.

( Figs. 18 –23)

Type locality. People’s Republic of China, Xinjiang, Badang Mt.

Range, right tributary to Kuga river, 3200 m a.s.l.

Type material. HOLOTYPE: J, CHINA: XINJIANG: “ CHINA NW-

Xinjiang Badan Mt. Range, 3200m right trib. to Kuga riv. 42°31’N

83°08’E ” / “16.– 17.7.2008 leg. J. Kaláb alpine meadows, screes”

( NHMW). PARATYPES: CHINA: XINJIANG: same data as holotype, 1

J ( ASC); “N slope of Tian Shan mts. Road Kuqa-Bayanbulak 50km

SW BAYANBULAK, ca 2800m, 10.VII.1993, Jaroslav Turna leg.”,

2 JJ ( ASC, NHMW).

Description. Head, pronotum and abdomen black, tergite two (in front of first visible tergite), apical margin of fifth visible tergite, sixth visible tergite and genital segment brunneo-rufous; elytra brunneo-rufous; pubescence of entire dorsal surface of body testaceous; mandibles dark rufo-brunneous, darkened toward apices; maxillary and labial palpi testaceous, antennae dark brunneous with first three segments rufo-brunneous, legs brunneo-rufous.

Head of rounded quadrangular shape, with entirely rounded, not apparent posterior angles, wider than long

(ratio 1.23), eyes small, flat, tempora considerably longer than eyes from above (ratio 1.82), disc of head and front portion of head quite sparsely and finely punctate, with some extremely fine intermixed punctures, punctation becoming gradually somewhat coarser and denser on postriolateral portions of head, interspaces between punctures without any microsculpture, highly shiny,

polished. Antenna moderately long, segment three longer than segment two (ratio 1.25) segments four to eight longer than wide, gradually becoming shorter, segments nine and ten about as long as wide, last segment shorter than two preceding segments combined. Pronotum longer Fig. 23. Tasgius venustus sp. nov. Habitus. than wide (ratio 1.30), parallelsided, with moderately Photo: E. Jendek. rounded base, narrow marginal groove disappearing downward at about posterior third of pronotal length; disc of pronotum with entire impunctate midline; punctation similar to that on head, but in general finer, sparser and variably, irregularly spaced, interspaces between punctures on disc highly shiny, polished. Scutellum very finely, moderately densely, punctate and pubescent, interspaces between punctures with rudimentary, extremely fine microsculpture. Elytra rather short, at suture slightly shorter than (ratio 0.88), at sides vaguely shorter than (ratio 0.94) to as long as pronotum at midline; punctation moderately fine and dense; transverse interspaces between punctures mostly about as large as diameters of punctures, lacking any microsculpture, pubescence dense. Wings reduced to nonfunctional stumps. Abdomen with fifth visible tergite lacking pale apical seam of palisade setae; tergite two (in front of first visible tergite) entirely punctate and pubescent; punctation of tergites coarser than that on elytra, gradually becoming finer and sparser toward apical margin of each tergite, and in general toward apex of abdomen, interspaces between punctures with extremely fine, rudimentary microsculpture.

Male. Sternite 8 with narrow, rather shallow, obtusely triangular medioapical emargination. Genital segment with tergite 10 evenly narrowed toward broadly subtruncate apex, setose as in Fig.18 ; sternite 9 with narrow basal portion and with apex of apical portion narrowly arcuate, setose as in Fig. 19 . Aedoeagus as in Figs. 20–22 , rather simple; median lobe with short, asymmetrically located apical portion with acute apex; paramere situated on median lobe asymmetrically, narrow, elongate, shaped as in Fig. 20 , with narrowly arcuate apex not quite reaching apex of median lobe ( Fig. 21 ); underside of paramere without sensory peg setae but with several variably long apical setae, situated as in Fig. 22 .

Female. Unknown.

Length 13.0–14.0 mm (abdomen extended, see Comments).

Etymology. The specific epithet is the Latin adjective venustus , - a, - um (charming, cute). It refers to the general appearance of the species.

Bionomics. The specimens were taken from pitfall traps. Those in Badan Range were set in alpine habitat (3200 m a.s.l.) of meadows and screes. No details are known for traps set 50 km SW Bayanbulak, except that they were set at lower elevation of 2800 m a.s.l.

Geographical distribution. Tasgius venustus sp. nov. is at present known from two localities in northwestern Tibet (Xinjiang).

Recognition and comments. Due to its small size and distinctive coloration, T. venustus sp. nov. cannot be confused with any other species of Tasgius s. str.

All specimens of the original series were mounted with quite extended abdomens (see above). The actual size is estimated at 8.0–10.0 mm.

Figures

Figs. 16–22. 16–17 – Tasgius congener sp. nov. 16 – aedoeagus, ventral view; 17 – apical portion of underside of paramere.18–22 – Tasgius venustus sp. nov.18 – tergite 10 of male genital segment; 19 – sternite 9 of male genital segment; 20 – aedoeagus, ventral view; 21 – aedoeagus, lateral view; 22 – apical portion of underside of paramere.