(Figs. 42–50)
Type locality. People’s Republic of China: Sichuan, Gongga Shan, Lake above Camp 2, 2750 m.
Type material. Holotype (male) and allotype (female): China: CHINA, Sichuan, Gongga Shan, Lake abv. Camp 2 2750 m, 24.VII. 1994 A. Smetana [C 20]. In the Smetana collection, Ottawa, Canada (to be eventually deposited in the Muséum d’histoire naturelle, Genève, Switzerland).
Paratypes: China: [Sichuan]: same data as holotype [89] (ASC, MSC); same data as holotype, but 25. VII. 1994, A. Smetana [C 23], [33] (ASC); same data as holotype, but 27.VII. 1994, A. Smetana [C 27], [10] (ASC); Gongga Shan, above Camp 3, 3050 m, 22.VII. 1994, A. Smetana [C 18], [5] (ASC); Gongga Shan, Hailuogou, head of Glacier 1, 2850 m, 9. VII.1996, 29° 35 ʹN 10 ° 200 ʹE C 57 / collected by A. Smetana, J. Farkač and P. Kabátek [5] (ASC); Gongga Shan, Hailuogou, Lake above Camp 2, 2750 m, 29 ° 35 ʹN 10 ° 200 ʹE, 4.VII. 1998, A. Smetana [C 74] / 1998 China Expedition J. Farkač, D. Král, J. Schneider & A. Smetana [5] (ASC); Gongga Shan, Hailuogou, for. above Camp 2, 2800 m, 29 ° 35 ʹN 10 ° 200 ʹE, 5.VII. 1998, A. Smetana [C 75] / 1998 China Expedition J. Farkač, D. Král, J. Schneider & A. Smetana [2] (ASC); Gongga Shan, Hailuogou, in front of Glacier 1, 2850 m, 29 ° 35 ʹN 10200 ʹE, 7.VII. 1998, A. Smetana [C 76] / 1998 China Expedition J. Farkač, D. Král, J. Schneider & A. Smetana [42] (ASC, NMW); W-Sichuan (7) Daxue Shan, W Kangding 3003 ʹ 13 ʺN 10157 ʹ 11 ʺE 2700–2800 m, 24.05. 1997, M. Schülke [1] (MSC); W-Sichuan Ya’an Pref., Shimian Co. Daxue Shan, road betw. Anshunghang - Wanba, 20 km WSW Shimian, 1500 m, 9.VII. 1999, leg. A. Pütz [1] (APC).
Description. In all external characters similar to Q. aureiventris BERNHAUER, 1915 (detailed description in SMETANA 1988: 250), and different mainly by the male sexual characters, particularly by the shape of the aedoeagus, and by the uniformly dark pubescence of the elytra (elytral pubescence in Q. aureiventris is a mixture of dark and golden or golden-yellowish hairs).
M a l e. First four segments of front tarsus markedly dilated (about the same way as those of Q. aureiventris), sub-bilobed, each densely covered with tenent setae ventrally, segment 2 about as wide as apex of tibia, segment 4 narrower than preceding segments. Sternite 8 with two long setae on each side, with wide, moderately deep medioapical emargination, not appreciably different from that of Q. aureiventris (Fig. 42), small triangular area before emargination flattened and smooth. Genital segment with tergite 10 wider and less setose than that of Q. aureiventris (Figs. 43, 51); sternite 9 wider than that of Q. aureiventris, with apex subtruncate to subemarginate (Figs. 44, 52), with two slightly differentiated apical setae. Aedoeagus (Figs. 45–49) narrow, elongate, similar to that of Q. aureiventris, but median lobe widely attenuate in middle portion (almost parallelsided in Q. aureiventris), anteriorly distinctly widened before narrowed into apical portion with subacute apex (Figs. 45, 47), apical portion darkened (in Q. aureiventris median lobe not widened before apical portion and apical portion not darkened), medial carina on face adjacent to paramere longer than that of Q. aureiventris, appearing as minute dent in lateral view; paramere parallelsided, similar to that of Q. aureiventris but in general wider, with arcuate apex not quite reaching apex of median lobe; four fine setae at apical margin (Figs. 48, 49), medial setae sometimes longer than lateral ones (Fig. 49), two similar setae at each lateral margin below apex; sensory peg setae on underside of paramere numerous, forming two variably long, slightly irregular, rows not appreciably different from those of Q. aureiventris (Figs.48, 49).
F e m a l e. First four segments of front tarsus not appreciably dilated. Tergite 10 of genital segment somewhat wider and longer than that of Q. aureiventris, less densely setose (Figs. 50, 53).
Length 4.3 –5.0 mm.
Geographical distribution. Quedius impressiventris is at present known from the Daxue Shan range, particularly from Gongga Shan, in Sichuan.
Bionomics. The long series of specimens collected at the lake above Camp 2 on Gongga Shan was taken by submerging soaking wet moss and various vegetation, growing along the edges of the shallow lake, into water. Quedius euryalus Smetana, 1997 was collected in the same habitat.
Recognition and comments. Quedius impressiventris and the following species, Q. tergimpressus, are both similar and closely related to the Himalayan Q. aureiventris, as it is stipulated in the respective descriptions. They both differ from Q. aureiventris by the characters given in the descriptions, and they differ from each other by the characters on the aedoeagus. It is the distinct anterior widening of the median lobe of the aedoeagus (Fig. 47) that is typical for Q. impressiventris and is absent in Q. tergimpressus (Fig. 58), and the fusiform paramere (Fig. 57) that characterizes Q. tergimpressus.
Etymology. The specific epithet is a combination of the Latin adjective impressus, - a, - um (impressed) and the noun venter, - tris, m (abdomen). It refers to the inconspicuous impressions on the abdominal tergites.