Ischnosoma foedum, 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 : 209-212

Ischnosoma foedum sp. n.

Figs 13 , 16–19 , 46 , 55 .

Description. Body ( Fig. 13 ) reddish-brown to brownish. Head (except mouthparts), central portion of elytra, and anterior portions of tergites (especially tergite V to VII) darker, balckish. Pronotum in anterior and median portions often with darker spot. Expansion of dark colour is variable. Legs, antennae and palpi yellow to brownish-yellow, antennae often darker, reddish-brown. Elytra with a slight greenish hue.

Head 0.51–0.58 mm broad; 0.55–0.60 times as broad as pronotum. Surface smooth without microsculpture, rarely with very inconspicuous microsculpture. Antenna slender, 1.26–1.46 mm long. Antennomere X as long as broad or slightly longer than broad.

Pronotum 0.88–1.01 mm broad; 0.73–0.83 mm long; 1.2–1.27 times as broad as long. Surface shiny with very fine, more or less indistinct microsculpture, finely and sparsely punctate.

Elytra distinctly widened posteriad, along suture 0.68–0.79 mm long; 1.09–1.2 times as broad as pronotum; 0.93–0.98 times as long as pronotum. Surface with very fine transverse microsculpture. Sutural row with 8 to 10 punctures, discal row with 7 to 10 punctures, and lateral row with 7 to 10 punctures. Hind wings reduced.

Abdomen gradually tapering towards apex, very sparsely puntate. Latero-tergites and tergites apically with long, stout, dark setae. Tergite VII without palisade fringe. Surface smooth without distinct microsculpture.

Length of forebody 1.87–2.27 mm; total body length 3.6–4.8 mm.

Male. Sternite VII with posterior margin slightly concave, along central part of posterior margin with thin long setae ( Fig. 16 ). Sternite VIII with areas of palisade and beard-like setae forming three to four rows; and with area of medial dense and posteriorly flattened and pointed setae. Setae in antero-lateral parts of sternite VIII longer, thin and diagonally postero-laterad ( Fig. 17 ). Paramere basally stout. Internal structure of aedeagus see Fig. 18 .

Etymology. The specific epithet (Latin adjective: ugly, ghastly) alludes to the indistinctive habitus of this species.

Type material. Holotype, male: "P.R. CHINA, Yunnan, E slope Cangshan at Dali, N25°40'15.5'', E100°07'45.4'', 18.V.2010, 2657 m, sifting 17, V. Grebennikov / coll. Smetana ( CAS)".

Paratypes (52): same data as the holotype (4 exs.) (cKoc, cSch, cSme); "P.R. CHINA, Yunnan, E slope Cangshan at Dali, N25°40'15.1'', E100°07'39.9'', 10.V.2010, 2711 m, sifting 0 4, V. Grebennikov", 3 exs. ( CNC, cKoc); "P.R. CHINA, Yunnan, E slope Cangshan at Dali, N25°40'13.2'', E100°07'54.8'', 11.V.2010, 2728 m, sifting 0 5, V. Grebennikov", 11 exs. ( CNC, cKoc); " CHINA: N-Yunnan Dali Bai Nat. Aut. Pref. Diancang Shan 3 km E Dali, 25°41'N, 100°07'E, 29.VIII.2003, 2700 m, A. Smetana [C138]", 1 ex. (cSme); " CHINA: N-Yunnan Dali Bai Nat. Aut. Pref. Diancang Shan 5 km SSW Dali, 25°38.7'N, 100°08.3'E, 26.VIII.2003, 2800 m, A. Smetana [C136]", 1 ex. (cSme); " CHINA: Yunnan, above Dali, 2700–2900 m, 14.IV.1999, leg. W. Schawaller", 2 exs. ( SMNS); " CHINA: Yunnan, above Dali, 2500–2700 m, 8.–18.IV.1999, leg. W. Schawaller", 4 exs. ( SMNS, cKoc); " CHINA (N-Yunnan), Dali Bai Nat. Aut. Pref., Diancang Shan, 5 km SSW Dali old town, creek valley above cablecar, 2800 m, 25°38.7'N, 100°08.3'E (shrubs, bamboo, moss, old flood debries), 26.VIII.2003, Wrase [15] / Sammlung M. Schülke, Berlin", 5 exs. (cSch, cKoc); " CHINA (N-Yunnan), [C03-15] Dali Bai Nat. Aut. Pref., Diancang Shan, 5 km SSW Dali old town, creek valley above cablecar, 2800 m, 25°38.7'N, 100°08.3'E (shrubs, bamboo, moss, old flood debries), 26.VIII.2003, M. Schülke / Sammlung M. Schülke, Berlin", 2 exs. (cSch); " CHINA (N-Yunnan), [ CH 07-03] Dali Bai Nat. Aut. Pref., Diancang Shan W Dali, 25°41'49''N, 100°06'24''E, 2970 m, sifted at rock edges and under small shrubs, 28.V.2007, M. Schülke / Sammlung M. Schülke, Berlin", 1 ex. (cSch); " CHINA (N-Yunnan), [ CH 07-05] Dali Bai Nat. Aut. Pref., Diancang Shan W Dali, 25°41'33''N, 100°06'36''E, 2927 m, litter at moist escarpment sifted, under stones, 28.V.2007, M.Schülke / Sammlung M. Schülke, Berlin", 3 exs. (cSch, cKoc); " CHINA: Yunnan, Dali Bai Aut. Pref., Zhemo Shan, 7 km SW Xiaguan, 25°32–33'N, 100°10–11'E, 2870–2970 m, scrub with bamboo, oaks & Rhododendr., litter sifted, 18.IX.2009, leg. M.Schülke [ CH 09-60] / Sammlung M. Schülke, Berlin", 6 exs. (cSch, cKoc); " CHINA: Yunnan, Dali Bai Aut. Pref., Zhemo Shan, 7 km SW Xiaguan, 2870–2970 m (scrubs with bamboo, oaks, Rhododendr., litter sifted), 25°32–33'N, 100°10–11'E, 18.IX.2009, D.W.Wrase [60] / Sammlung M. Schülke, Berlin", 8 exs. (cSch, cKoc); " CHINA: Yunnan, Dali Bai Aut. Pref., Jizu Shan, summit plateau, 37 km NE Dali, 3150 m, (mixed forest, sifted from litter, moss), 25°58'30''N, 100°21'36''E, 5.IX.2009, D.W.Wrase [28] / Sammlung M. Schülke, Berlin", 1 ex. (cSch).

Distribution. Northwestern Yunnan ( Fig. 19 ): mountain ranges arround Er Hai Lake (Diancang Shan, Zhemo Shan, Jizu Shan).

Remarks. I. foedum sp. n. belongs to the I. pictum species group. It differs from the other Chinese species with a similar chaetotaxy of the male sternite VIII by shorter, posteriorly distinctly widened elytra with less than 10 discal punctures, completely reduced hind wings, shorter antennae, a generally shinier body surface, and the shape of the large internal sclerite of the aedeagus (broad in lateral view and blunt apically; Fig. 18 ).

Figures

FIGURE 19. Distribution of Ischnosoma foedum sp. n. (diamonds), Ischnosoma abstrusum sp. n. (circles) and Ischnosoma yunnanum sp. n. (squares) in China.

FIGURES 13 – 15. Habitus of Ischnosoma foedum sp. n. (13); Ischnosoma gemellum sp. n. (14); Ischnosoma involutum sp. n. (15).

FIGURES 16 – 18. Ischnosoma foedum sp. n. Male sternite VII (16); male sternite VIII (17); apical portion of aedeagus in ventral (left) and aedeagus in lateral view (18). Scale bars: 0.1 mm: a (Figs 16 – 17), b (Fig. 18).

FIGURES 46 – 53. Male sternite VIII with position of dark setae, beard-like palisade setae and median dense setae, schematic. Ischnosoma foedum sp. n. (46); I. noemi Kocian (47); I. splendidum (Gravenhorst) (48); I. maderi (Bernhauer) (49); I. duplicatum (Sharp) (50); I. involutum sp. n. (51); I. abstrusum sp. n. (52); I. yunnanum sp. n. (53). Scale bar: 0.1 mm.

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.