Ischnosoma jumla Kocian & Schülke, 2018

Kocian, Matúš & Schülke, Michael, 2018, New species and records of Ischnosoma Stephens (Coleoptera: Staphylinidae: Tachyporinae) from Nepal, Zootaxa 4442 (4), pp. 501-522 : 508-510

Ischnosoma jumla Kocian & Schülke , sp. n.

Figs 4 , 11 , 21–25 , 33 .

Description. Body uniformly rufotestaceous, anterior parts of tergites darker. Legs, palpi and antennomeres I–II yellowish, antenna from third antennomere darker, brownish ( Fig. 4 ).

Habitus as in Figs 4 , 11 . Head 0.48–0.53 mm wide; 0.57–0.63 times as wide as pronotum, as wide as long. Eyes about 1.5 times as long as temples. Ocular puncture missing. Surface without microsculpture. Antenna 1.11– 1.29 mm long. Antennomeres IX–X distinctly wider than long.

Pronotum 0.75–0.86 mm broad; 0.65–0.75 mm long; 1.14–1.24 times as wide as long, widest in posterior half. Surface with sparse transverse microsculpture. Anterior and posterior punctures separated from pronotal margin by 1–2 times the diameter of punctures.

Elytra quadrangular, parallel-sided or slightly widened posteriad, along suture 0.58–0.73 mm long; 1.01–1.10 times as wide as pronotum; 0.84–0.96 times as long as pronotum. Surface with shallow transverse microsculpture similar to that of pronotum. Sutural and discal row with 6–9 punctures, lateral row with 6–10 punctures. Wings reduced.

Abdomen parallel-sided, slightly tapering towards apex, sparsely punctate. Tergite VII without palisade fringe. Surface smooth, with or without very indistinct transverse microsculpture.

Length of forebody 1.69–2.15 mm; total body length 3.41–4.8 mm.

Male. Apical margin of sternite VII slightly concave, with long thin setae in the middle ( Fig. 21 ). Apical margin of sternite VIII with 4–5 rows of palisade setae and with relatively short beard-like setae. Sternite VIII in median portion with triangular cluster of denser, shorter, and pointed setae ( Fig. 22 , 33 ). Aedeagus as in Fig. 23 .

Type material. Holotype, male: 579 NEPAL: Jumla Distr. , Ghurchi –Lagna Pass, 3500 m, 14.VI.1998, leg. W. Schawaller ( SMNS).

Paratypes (13): same data as holotype, 1♂ (cKoc); 576 Nepal, Mugu Distr. , SW Rara Lake, 3200 m, 12.VI.1998, leg. W. Schawaller, 1♂, 2♀♀ ( SMNS, cSch); Nepal, Prov . Seti, Distr. Bajura, 19 km WSW Simikot, Kuwadi Khola valley , 3500–3700 m NN, 05.VII.2001, 29°53'10''N, 81°38'40''E, leg. M. Hartmann, Laubgesiebe, fir-birch forest, 1♂ ( NME); Nepal, Prov . Karnali, Distr. Humla, 20 km W Simikot, 3 km W Chala, 4000–4300 m, 29°50'46''N, 81°35'55''E, 24.06.2001, leg. A. Kopetz, snow fields HF, 1♂ ( NME); Gebiet von Jumla, Westnepal, lg. H. Franz, Umg. Alm Darghari, b. Maharigaon, 4000 m, 4♂♂ ( NMW, cKoc, cSch); Gebiet von Jumla, Westnepal, lg. H. Franz, Dzunda – Khola Tal, b. Talphi, 3000–3500 m, 1♂ ( NMW); Gebiet von Jumla, Westnepal, lg. H. Franz, Dampa Pass, gegen Chauta, 1♂ ( NMW); Nepal, Manaslu Mts. , Bara Pokhari Lekh, 3000 m, 4.4.1999, leg. Hirthe, Jäger, Schmidt, 1♂ (cHir).

Etymology. The specific name (noun in apposition) alludes to the Nepalese district Jumla, where the holotype was collected.

Distribution. North of Central and West Nepal, Bajura, Gorkha, Humla, Jumla, and Mugu districts ( Fig. 24 ).

Remarks. I. jumla sp. n. belongs to the I. pictum species group. Its habitus resembles that of three related Nepalese species: I. jaljalense (Coiffait) , I. nepalense (Scheerpeltz) and I. nepalicum (Coiffait) . Ischnosoma jumla differs from these species by smaller body size and the following combination of male sexual characters: clusters of modified palisade and beard-like setae of sternite VIII relatively small, somewhat similar to those of I. nepalicum ; shapes of the apices of the paired sclerites of the internal sac of the aedeagus characteristic ( Fig. 25 ). See also remarks in the section on I. nepalicum .

Figures

FIGURE 24. Distribution of Ischnosoma jumla sp. n. (red diamonds), Ischnosoma bhojpur sp. n. (green squares), Ischnosoma schmidti sp. n. (blue circle) and Ischnosoma hirtei sp. n. (yellow triangle).

FIGURES 2–7. Habitus of Ischnosoma bhojpur sp. n., Holotype (2); Paratype, darkened specimen (3); Ischnosoma jumla sp. n., Paratype (4); Ischnosoma hirtei sp. n., Holotype (5); Ischnosoma schmidti sp. n., Paratype (6); Ischnosoma fasciatocolle, partially darkened specimen (7). Scale bars: 1 mm.

FIGURES 8–11. Forebody. Ischnosoma hirthei sp. n. (8), I. bhojpur sp. n. (9), I. schmidti sp. n. (10), I. jumla sp. n. (11). Scale bar: 1 mm.

FIGURES 21–23. Ischnosoma jumla sp. n. Male sternite VII (21); male sternite VIII (22); aedeagus in ventral (left) and lateral view (23). Scale bars: 0.1 mm: a (Figs 21–22), b (Fig. 23).

FIGURES 25–31. Extruded internal sac of aedeagus from lateral view (25–27), apical portion of male sternite VII with position of dark long setae (28–30), apical portion of male sternite VIII (31). Ischnosoma jumla sp. n. (25), I. nepalicum (26), I. nepalense (27), I. quadriguttatum quadriguttatum (28), I. travei (29, 31), I. gratiosum (30). Scale bars: a (Figs 28–31), b (Figs 25–27).

FIGURES 32–39. Male sternite VIII with position of dark setae, beard-like palisade setae and median dense setae, schematic. Ischnosoma iob (32), I. jumla sp. n. (33), I. jaljalense (34), I. fasciatocolle (35), I. nepalense (36), I. nepalicum (37), I. ephraim (38), I. thamar (39). Scale bar: 0.1 mm.