Tasgius (Tasgius) pugio, 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 : 150-151

Tasgius (Tasgius) pugio sp. nov.

( Figs. 10–13 )

Type locality. People’s Republic of China, Gansu, Wagatan Timber, ca. 25 km E Xiahe.

Type material. HOLOTYPE: J, CHINA: GANSU: “China (Gansu) ca 25 km E Xiahe 2700–2900m (Wagatan Timber) 30.VII.-2.VIII.1993 Heinz leg.” ( ASC, to be eventually deposited in MHNG) . PARATYPE: J, CHINA: GANSU: “ China, Gansu prov. 120 km SW Lanzhou PONGGARTANG 30. VI.-2.VII.1992 Jaroslav Turna leg.” ( NHMW).

Description. Black, head and pronotum shiny; maxillary and labial palpi piceous-black, last segment of maxillary palpus paler; antennae dark brunneous, first three segments black, following segments becoming paler, outer segments greyish-brown; legs piceous-black to black with paler tarsi. Head of rounded quadrangular shape, with entirely rounded, not apparent posterior angles, wider than long (ratio 1.22), eyes moderately large, flat, tempora longer than eyes from above (ratio 1.20), disc of head and front portion of head sparsely and rather finely punctate, with some extremely fine intermixed punctures, vertex with variably large and shaped impunctate area, punctation becoming gradually somewhat coarser and denser on posteriolateral portions of head, tempora rather densely punctate and pubescent; interspaces between punctures without any microsculpture, highly shiny, polished. Antenna moderately long, segment three longer than segment two (ratio 1.20), 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 than wide (ratio 1.20), parallelsided, with moderately 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 moderately densely, finely punctate and pubescent, interspaces between punctures with rudimentary, extremely fine microsculpture. Elytra rather short, at suture shorter (ratio 0.78), at sides vaguely shorter (ratio 0.95) as pronotum at midline; punctation very fine, sparse, transverse interspaces between punctures mostly distinctly larger than diameters of punctures, lacking any microsculpture. Wings reduced to minute 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 microsculpture of short transverse striae.

Male. Sternite 8 with moderately wide and deep, obtusely triangular medioapical emargination. Genital segment with tergite 10 rather narrow, evenly narrowed toward subtruncate apex, with densely set, variably long setae at and near apical margin, otherwise with short, moderately dense setation ( Fig. 10 ); sternite 9 rather elongate, with short basal portion, with apex of apical portion narrowly arcuate ( Fig. 11 ). Aedoeagus as in Figs. 12, 13 ; median lobe slightly asymmetrical, with short, asymmetrically located apical portion shaped as in Fig. 12 , apical portion in right lateral view of obtuse triangular shape; paramere situated on median lobe asymmetrically, narrow, elongate, shaped as in Figs. 12, 13 , with narrowly arcuate apex not quite reaching apex of median lobe; underside of paramere without sensory peg setae but with several variably long apical setae, situated as in Fig. 13 .

Female unknown.

Length 14.0–15.0 mm (abdomen extended, see Comments).

Etymology. The specific epithet is the Latin noun pugio , - onis (a dagger), in apposition. It refers to the shape of the paramere.

Bionomics. The specimens were taken from pitfall traps, but nothing is known about the habitats the traps were set in.

Geographical distribution. Tasgius pugio sp. nov. is at present known from two localities, both located about 120 km SW of Lanzhou.

Recognition and comments. Tasgius pugio sp. nov. may be easily distinguished from T. praetorius , in addition to the distinctly smaller size and the differently shaped aedoeagus ( Figs. 3 , 12 ), by the entirely punctate and pubescent abdominal tergite two (in front of the first visible tergite). This character state is shared with T. congener sp. nov., but the latter may be easily distinguished by the differently shaped aedoeagus.

Both specimens of the original series, particularly the paratype, are mounted with quite extended abdomen. The actual size is estimated at 11.0–12.0 mm.

The paratype is missing four terminal segments of right antenna, and three terminal segments of left antenna.

The correct spelling of the locality Ponggartang on the locality label is Panggurtang.

Figures

Figs. 7–15. 7–9 – Tasgius praetorius Bernhauer, 1915. 7 – tergite 10 of male genital segment; 8 – sternite 9 of male genital segment (showing large apical seta); 9 – tergite 10 of female genital segment (setation in Figs. 7–9 not shown). 10–13 – Tasgius pugio sp. nov. 10 – tergite 10 of male genital segment; 11 – sternite 9 of male genital segment; 12 – aedoeagus, ventral view; 13 – apical portion of underside of paramere. 14, 15 – Tasgius congener sp. nov. 14 – tergite 10 of male genital segment; 15 – sternite 9 of male genital segment.

Figs. 1–6. Tasgius praetorius Bernhauer, 1915. 1 – tergite 10 of male genital segment; 2 – sternite 9 of male genital segment; 3 – aedoeagus, ventral view; 4 – aedoeagus, lateral view; 5 – apical portion of underside of paramere; 6 – tergite 10 of female genital segment.