Rhyncocheilus gonggashanus Tang, Schillhammer & Zhao, 2021

Tang, Liang, Schillhammer, Harald & Zhao, Xin, 2021, Notes on the genus Rhyncocheilus in China (Coleoptera, Staphylinidae Staphylininae) with descriptions of three new species, Zootaxa 4948 (1), pp. 99-112 : 104-108

Rhyncocheilus gonggashanus Tang, Schillhammer & Zhao sp. n.

( Figs. 9, 10 , 25–27 , 50–53)

Rhyncocheilus griseosericans ; Schillhammer, 2012: 199 (partim).

Type material. Holotype. China: Sichuan: ³, glued on a card with labels as follows: “ China: Sichuan Prov. , Mt.

Gonggashan, Hailuogou, Qingshibangou , alt. 2300 m, 15.VII.2011, Huang Hao leg.” “ Holotype / Rhyncocheilus gonggashanus / Tang, Schillhammer & Zhao” [red handwritten label] ( SHNU) . Paratypes. 1♀, same data as for the holotype ( SHNU) ; 1³, same locality, alt. 1900–2000 m, 26.VII.2006, Hu & Tang leg. ( SHNU) ; 1³ 1♀, 40 km S Luding, Moxi village, Hailuogou glacier park, Gongga Shan, 2000–3200 m, 14–20.VIII.1995, J. Schneider leg. ( CSS, NMW) .

Description. Measurements of male: BL: 18.0 mm, FL: 11.3–12.1 mm, HL: 2.89–3.17 mm, HW: 2.84–3.03 mm, EYL: 1.06 mm, TL: 1.28–1.56 mm, PL: 2.78 mm, PW: 2.78–2.84 mm, EL: 4.78–5.23 mm, EW: 5.00– 5.28 mm. HW/HL: 0.96–0.98, TL/EYL: 1.21–1.47, PL/PW: 0.98–1.00, EL/EW: 0.96–0.99.

Measurements of female: BL: 24.6 mm, FL: 14.0 mm, HL: 3.67 mm, HW: 3.39 mm, EYL: 1.11 mm, TL: 1.95 mm, PL: 3.34 mm, PW: 3.56 mm, EL: 5.73 mm, EW: 6.56 mm. HW/HL: 0.92, TL/EYL: 1.75, PL/PW: 0.94, EL/ EW: 0.87.

The new species is extremely similar in appearance to Rhyncocheilus griseosericans ( Fairmaire, 1894) , and the external characters have been described in the redescription part of R. griseosericans (page 199 in Schillhammer, 2012). Therefore, only a few diagnostic characters of the new species versus R. griseosericans need to be mentioned here: median basal portion of head is more convex than that of R. griseosericans ; surface of labrum ( Fig. 27 ) with more setae than that of R. griseosericans ; silvery pubescent patch of elytra longer than that of R. griseosericans ; silvery pubescent patch of abdominal tergite VII longer than that of R. griseosericans .

Male. Head ( Fig. 25 ) with posterior angles less prominent; sternites VII and VIII emarginate in the middle of posterior margin; aedeagus ( Figs 50, 51 ) with median lobe similar to that of R. griseosericans , but apicolateral projection more prominent ( Fig. 52 ); paramere slightly shorter than median lobe, slenderer than in R. griseosericans , apex rounded, inner side of apical portion densely covered with peg setae ( Fig. 53 ), which are distinctly less numerous than in R. griseosericans .

Female. Head ( Fig. 26 ) with posterior angles more prominent; sternites VII and VIII with posterior margin en- tire. The silvery pubescent patch of elytra is somewhat shorter than that of males: a larger humeral portion remains uncovered by the silvery pubescence. Whether this is variability or sexual dimorphism cannot be judged based on the small number of specimens presently available.

Distribution. China (Sichuan).

Diagnosis. The differences between R. griseosericans and the new species have been mentioned above. The new species is also similar to R. sommersgutteri, Schillhammer, 2004 from Sichuan, but it may be distinguished from the latter by the darker body color, the more extensive silvery pubescent patch of abdominal tergite VII and the different shape of the aedeagus.

Etymology. This specific name is derived from the type locality of the new species.

Figures

FIGURES 7–12. Habitus. 7, 8—Rhyncocheilus griseosericans; 9, 10—R. gonggashanus; 11, 12—R. yangxiaodongi. Scale bars: 2 mm.

FIGURES 22–29. 22–24—Rhyncocheilus griseosericans; 25–27—R. gonggashanus; 28, 29—R. yangxiaodongi; 22, 25, 28— male head; 23, 26—female head; 24, 27, 29—Labrum. Scale bars: 1 mm.

FIGURES 46–53. Aedeagal characters. 46–49—Rhyncocheilus griseosericans from Emeishan; 50–53—R. gonggashanus; 46, 50—aedeagus in lateral view; 47, 51—aedeagus in ventral view; 48, 52—apical portion of aedeagal median lobe in ventrolateral view; 49, 53—inner side of apical parameral portion. Scale bars: 0.5 mm.