Ischnosoma yunnanum, 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 : 213-214

Ischnosoma yunnanum sp. n.

Figs 3 , 19 , 23–26 , 53 , 58 .

Description. Body ( Fig. 3 ) blackish, anterior margin of pronotum, humeral spot and posterior margin of elytra, posterior margins of tergites, legs, palpi and basal two antennomeres brownish-yellow. Pronotum, elytra, and abdomen with distinct blue-goldish hue.

Head 0.65–0.68 mm broad; 0.62–0.65 times as broad as pronotum, distinctly broader than long, narrower posteriad, broadest in the middle. Eyes very large and bulbous, more than twice as long as temples. Surface smooth without microsculpture. Antenna stout and very long (1.84–2.12 mm). Antennomere X distinctly longer than broad.

Pronotum 1.03–1.04 mm broad; 0.88 mm long; 1.17–1.18 times as broad as long. Posterior half of pronotum parallel-sided, posterior angles acute. Surface with very fine transverse microsculpture, finely and sparsely punctate.

Elytra distinctly widened posteriad; along suture 1.21 mm long; 1.3–1.41 times as broad as pronotum; 1.37 times as long as pronotum. Surface with very fine transverse microsculpture. Sutural row with 16–18 punctures, discal row with 17–18 punctures and lateral row with 17–18 punctures. Hind wings fully developed.

Abdomen gradually tapering towards apex, sparsely puntate. Tergite VII with palisade fringe. Surface smooth with very fine microsculpture.

Length of forebody 2.9 mm; total body length 5.0– 5.6 mm.

Male. Sternite VII at posterior margin distinctly and broadly concave, along central part of posterior margin with thin long setae ( Fig. 23 ). Sternite VIII with areas of palisade and beard-like setae forming six rows, these rows contiguous in the middle, and with medial area of very dense setae ( Fig. 24 ). Paramere and aedeagus: Figs 25–26 .

Etymology. The specific epitheth is an adjective derived from Yunnan, the Chinese province where this species was collected.

Type material. Holotype, male: " CHINA (Yunnan) Nujiang Lisu Pref., Gaoligong Shan, "Cloud pass" 3150 m, 21 km NW Liuku (shrubs, Vaccinium, bamboo, litter sifted), 25°58'21''N 98°41'01''E, 2.IX.2009, D.W.Wrase (22A) / Ischnosoma cf. rosti det. M. Schülke 2012 / Sammlung M. Schülke, Berlin" (cSch).

Paratypes (2): "P.R. China, Yunnan, E slope N Gaoligongshan, N 27°47'22.1'' E 098°32'17.7'', 24.V.2010, 3027 m, sifting 21, V. Grebennikov", 1 ex. ( CNC). " CHINA: N-Yunnan [C 2005-16] Nujiang Lisu Aut. Pref., Gongshan Co., Gaoligong Shan, side valley, 3000–3050 m, 27°47.90'N, 98°30.19'E / conif. forest with Rhododendron, broad leaved bushes, litter, moss, dead wood sifted along creek and snowfields, 21.VI.2005, leg. M. Schülke [C 2005- 16]", 1 ex. (cKoc).

Distribution. Northwestern Yunnan ( Fig. 19 ): northern and central parts of the Gaoligong Shan range. Remarks. I. yunnanum sp. n. differs from all similar Chinese species of the I. pictum group by the chaetotaxy of the male sternite VIII. It is the only species with contiguous areas of beard-like and palisade setae.

Figures

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

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

FIGURES 23 – 26. Ischnosoma yunnanum sp. n. Male sternite VII (23); male sternite VIII (24); apical portion of aedeagus in ventral (left) and lateral view (25); extruded inner structure of aedeagus in lateral view (26). Scale bars: 0.1 mm: a (Figs 23 – 24), b (Figs 25 – 26).

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 58 – 60. Forebody. Ischnosoma yunnanum sp. n. (58); I. abstrusum sp. n. (59); I. involutum sp. n. (60). Scale bar: 1 mm.