Ischnosoma zipapertum, Kocian, Matúš & Schülke, Michael, 2016

Kocian, Matúš & Schülke, Michael, 2016, New species and records of Ischnosoma Stephens (Coleoptera, Staphylinidae, Tachyporinae) from China, Zootaxa 4105 (3), pp. 201-242 : 205-207

Ischnosoma zipapertum sp. n.

Figs 4–8 , 56 .

Description. Body ( Fig. 4 ) reddish-brown; head, elytra and anterior part of tergites often darker, reddish-brown to brownish; legs, palpi and antenna brownish-yellow.

Head 0.40–0.45 mm broad; 0.55–0.59 times as broad as pronotum, as broad as long. Eyes slightly shorter than, or as long as temples. Ocular seta well developed, as long as setae of pronotum. Surface without microsculpture. Antenna 0.96–1.11 mm long. Antennomere X distinctly wider than long.

Pronotum 0.68–0.82 mm broad; 0.53–0.65 mm long; 1.22–1.29 times as broad as long, broadest in posterior half. Surface with distinct transverse microsculpture. Posterior angles relatively well marked. Anterior and posterior punctures separated from pronotal margin by 2–3 times the diameter of the punctures. Anterior margin of pronotum without carina.

Elytra quadrangular, parallel-sided, along suture 0.4–0.5 mm long; 1.00–1.04 times as broad as pronotum; 0.76–0.83 times as long as pronotum. Surface with distinct transverse microsculpture similar to that of pronotum. Sutural row with 6–8 punctures, discal row with 5–8 punctures and lateral row with 6–9 punctures. Wings reduced.

Abdomen parallel-sided, only slightly tapering towards apex, densely puntate. Tergite VII without whitish apical seam of palisade fringe. Surface smooth with very fine transverse microsculpture.

Length of forebody 1.39–1.69 mm; total body length 3.1–3.6 mm.

Male. Sternite VII with conspicuous modification, in the middle of posterior margin broadly and deeply concave, with medial dent carrying some short setae ( Fig. 5 ); sternite VIII in posterior margin in the middle of posterior margin very deeply concave, with 6–7 rows of modified setae similar to an opened zip ( Fig. 6 ); paramere and aedeagus: Fig. 7 .

Etymology. The specific name is composed of the English noun zip and the latin adjective apertus: opened. It alludes to the modified chaetotaxy of male sternite VIII, which somewhat resembles an opened zip.

Type material. Holotype, male: CHINA: "Yunnan [ CH 07-28A], Nujiang Lisu Aut. Pref., Gaoligong Shan, side valley 19 km NW Liuku, 25°59'02''N, 98°42'23''E, 2730 m, devast. prim. for., litter sifted, 10.VI.2007, M. Schülke / Sammlung M. Schülke, Berlin" (cSch).

Paratypes (30): same data as HT (12 exs.) (cSch, cKoc); same data as HT, but " 9.VI.2007 [ CH 07-28]", 1 ex. (cSch); " CHINA (Yunnan), Nujiang Lisu Aut. Pref., Gaologong Shan, creek valley, 20 km NW Liuku, 3000 m, 25°58'49''N, 98°41'48''E (bamboo, shrubs, litter sifted), 9.VI.2007, D.W.Wrase [27]", 2 exs. (cSch); " CHINA (Yunnan), Nujiang Lisu Aut. Pref., creek valley 3 km SE Gongshan, 27°43'02''N, 98°41'27''E, 1450–1500 m, (litter, moss, sifted), 5.VI.2007, D.W.Wrase [20] / Sammlung M. Schülke, Berlin", 1 ex. (cSch); " CHINA: Yunnan [ CH 07-28], Nujiang Lisu Aut. Pref., Gaoligong Shan, side valley 19 km NW Liuku, 25°59'02''N, 98°42'23''E, 2730 m, devast. Prim. Forest, litter sifted, 9.VI.2007, leg. A. Pütz", 4 exs. (cPüt); " CHINA Yunnan [ CH 07-30], Nujiang Lisu Aut. Pref., Nu Shan, 7 km NNW Coajian, 25°43'29''N, 99°07'57''E, 2420 m, second pine forest with shrubs, litter, bark sifted, 11.VI.2007, leg. A. Pütz", 1 ex. (cPüt); " CHINA (Yunnan) Nujiang Lisu Aut. Pref., Gaoligong Shan E pass 20 km NW Liuku, 3000 m (creek valley with devast. prim. forest, ferns, litter, moss, sift.), 25°58'49''N, 98°41'48''E, 3.IX.2009, D.W.Wrase [25] / Sammlung M. Schülke, Berlin", 2 exs. (cSch, cKoc); " CHINA: Yunnan, Nujiang Lisu Pref., Gaoligong Shan, E pass 20 km NW Liuku, 25°58'49''N, 98°41'48''E, 3000 m, creek valley with devast. prim. forest, litter & moss sifted, 3.IX.2009, leg. M. Schülke [ CH 09-25]", 1 ex. (cSch); " CHINA (Yunnan) Nujiang Lisu Aut. Pref., Gaoligong Shan, "Cloud Pass" 21 km NW Liuku, 25°58'21''N, 98°41'01''E, 3150 m, shrubs & bamboo, litter sifted, 2.IX.2009, leg. M.Schülke [ CH 09-22] / Sammlung M. Schülke, Berlin", 5 exs. (cSch, cKoc); " CHINA (Yunnan) Nujiang Lisu Aut. Pref., Gaoligong Shan, "Cloud Pass" 3150 m, 21 km NW Liuku (shrubs, Vaccinum, bamboo, litter sifted) 25°58'21''N / 98°41'01''E, 2.IX.2009, D. W. Wrase [22A] / Sammlung M. Schülke, Berlin", 1 ex. (cSch).

Distribution. Northwestern Yunnan ( Fig. 8 ). The species is widely distributed along the northern and central parts of the Gaoligong Shan range. One specimen was collected at the opposite side of the Salween river in the Nu Shan range.

Remarks. Ischnosoma zipapertum sp. n. is the second species of the I. spelaeum species group ( Kocian, 1997) recorded from China. It is distinguished from all other Chinese species, except I. taibaiense , by the long ocular seta (as long and stout as the setae of the pronotum), small eyes (shorter than temples), a broader head in relation to pronotum, shorter elytra, and generally smaller body. The modifications of the male sternites VII and VIII are unique, among the Chinese species of Ischnosoma including the only described Chinese species of the I. spelaeum species group: I. taibaiense (see Zhou et al. 2005: 810, figure 3, 4).

Figures

FIGURE 8. Distribution of Ischnosoma zipapertum sp. n. (circles) and I. taibaiense Zhu, Li & Zhao (triangles) in China (material examined and literature records).

FIGURES 2 – 4. Habitus of Ischnosoma vicinum sp. n. (2); Ischnosoma yunnanum sp. n. (3); Ischnosoma zipapertum sp. n. (4).

FIGURES 5 – 7. Ischnosoma zipapertum sp. n. Male sternite VII (5); male sternite VIII (6); aedeagus in ventral (left) and lateral view (7). Scale bars: 0.1 mm: a (Figs 5 – 6), b (Fig. 7).

FIGURES 54 – 57. Forebody. Ischnosoma vicinum sp. n. (54); I. foedum sp. n. (55); I. zipapertum sp. n. (56); I. gemellum sp. n. (57). Scale bar: 1 mm.