Lathrobium formidabile, Assing, 2013

Assing, V., 2013, On the Lathrobium fauna of China IV. Six new species from Sichuan (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 155-170 : 167-169

Lathrobium formidabile nov.sp.

( Figs 36-43 , Map 1 )

Type material: Holotype ♂: "Ch- Sichuan, 24.7.1995, 28.07N 101.05E, 30 km NW MULI/BOWA, mixed forest, ca. 3500 m, Jaroslav Turna leg. / Holotypus ♂ Lathrobium formidabile sp. n., det. V. Assing 2013" ( cAss).

Etymology: The specific epithet (Latin, adjective) alludes to the - in various respects - formidable appearance of this species.

Description: Body large; body length 14.0 mm; length of forebody 6.5 mm. Habitus as in Fig. 36 . Coloration: whole body reddish-brown, with the antennae somewhat darker.

Head ( Fig. 37 ) of subcircular shape, approximately as broad as long; posterior angles completely obsolete; punctation moderately fine and rather sparse, very sparse in median dorsal portion; interstices with fine and shallow microreticulation. Eyes ( Fig. 38 ) reduced to minute rudiments, without ommatidia and without pigmentation; size of eye rudiments subequal to antennomere II in cross-section; Antenna long and slender, 4.5 mm long; all antennomeres longer than broad.

Pronotum ( Fig. 37 ) approximately 1.3 times as long as broad and 0.88 times as broad as head; lateral margins weakly convex in dorsal view, broadly rounded towards posterior margin, posterior angles obsolete; punctation rather fine and moderately sparse; interstices without microsculpture.

Elytra ( Fig. 37 ) conspicuously short, 0.44 times as long as pronotum, and of weakly trapezoid shape, somewhat dilated posteriad; dorsal surface flat, lateral margins straight in dorsal view; humeral angles rather marked; combined posterior margins strongly concave; punctation dense, but weakly defined; interstices without microsculpture. Legs long and slender.

Abdomen approximately 1.1 times as broad as elytra; punctation extremely fine and dense; interstices with very shallow microsculpture; posterior margin of tergite VII without palisade fringe.

♂: protarsomeres I-IV moderately dilated; tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 39 ) moderately transverse, with shallow postero-median impression, this impression with a cluster of long and conspicuously dense black setae and with numerous presumable gland openings, anterior to impression with another cluster of gland openings and a tuft of long dense setae ( Fig. 40 ), posterior margin broadly concave; sternite VIII ( Fig. 31 ) distinctly transverse, posteriorly with somewhat denser, but not distinctly modified setae, and with two pairs of conspicuously long setae (posterior ones broken off in the holotype), posterior margin with angular projection on either side of middle; aedeagus ( Figs 42-43 ) relatively small in relation to body size, 1.6 mm long, weakly asymmetric, and of derived morphology; ventral process apically rounded in ventral view, subapically with pronounced median carina; dorsal plate lamellate, relatively short, and apically convex in dorsal view, apical portion not delimited from basal portion.

♀: unknown.

Comparative notes: The external and sexual characters to do not suggest closer phylogenetic affiliations to any of the previously known species groups from China. The species is characterized not only by the distinctive and derived male sexual characters, but readily distinguished from all other Chinese representatives of the genus by various external characters, too, particularly the strongly reduced eyes without ommatidia and without pigmentation (unique), its large body size combined with reddish-brown coloration, the conspicuously large and subcircular head, the extremely short elytra (unique), and the extremely dense and fine punctation of the abdomen. The structure and chaetotaxy of the male sternite VII is highly remarkable. Among Lathrobium species from China, similar clusters of gland openings are found only in the representatives of the L. celere group (distributed in Sichuan and in Yunnan; see ASSING in press b, c), which have such structures on the male sternite VIII (without associated tufts of long dense setae) and partly also, though less distinctly, on the male sternite VII.

Distribution and natural history:The type locality is situated in the Hengduan mountains to the northwest of Qiaowa (=Dawa) in western Sichuan ( Map 1 ). The holotype was collected in a mixed forest at an altitude of 3500 m. Morphological adaptations such as the reduced eyes, the short elytra, the long legs and antennae, the relatively pale body coloration, and the long setae on the abdominal apex (tergite and sternite VIII) suggest a hypogean habitat.

Figures

Map 1: Geographic position of the Xiling Xue Shan (filled circle), the Luoji Shan (open triangle), and the type locality of L. formidabile nov.sp. (star) in China.

Figs 36-43: Lathrobium formidabile nov.sp.: (36) habitus; (37) forebody; (38) head in lateral view; (39) male sternite VII; (40) median portion of male sternite VII; (41) male sternite VIII; (42-43) aedeagus in lateral and in ventral view. Scale bars: 36-39, 41: 1.0 mm; 40, 42-43: 0.5 mm.

Figs 28-35: Lathrobium verminatum nov.sp.: (28) habitus; (29) forebody; (30) male sternite VII; (31) male sternite VIII; (32-33) aedeagus in lateral and in ventral view; (34) female sternite VIII; (35) female tergites IX and X. Scale bars: 28-29: 1.0 mm; 30-35: 0.5 mm.