Lathrobium undosum, Assing, 2015

Assing, Volker, 2015, New species and additional records of Lathrobium and Elytrobium from the Palaearctic region, with special reference to the fauna of East Yunnan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 65 (1), pp. 41-74 : 45-47

Lathrobium undosum spec. nov.

( Figs 16–20 )

Type material: Holotype : “ NEPAL: Solu Khumbu , Lamiura Danda, 3500–3800 m, 27°34'N, 86°30'E, 28.V.–29.V.2013, leg. Hagge & Schmidt / Holotypus  Lathrobium undosum spec. nov., det. V. Assing 2014” ( NME).

Etymology: The specific epithet (Latin, adjective: wavy) alludes to the shape of the dorsal plate of the aedeagus in lateral view.

Description: Small species; body length 5.3 mm; length of forebody 2.6 mm. Coloration: forebody brown; abdomen dark-brown with slightly paler apex; legs yellowishbrown; antennae dark-reddish.

Head ( Fig. 16 ) weakly transverse, approximately 1.03 times as broad as long, distinctly widened behind eyes; punctation rather coarse and dense, sparser in median dorsal portion; interstices without microsculpture. Eyes small and weakly convex, not projecting from lateral contours of head, approximately one-fifth as long as postocular region in dorsal view and composed of approximately 20 ommatidia. Antenna 1.45 mm long.

Pronotum ( Fig. 16 ) 1.25 times as long as broad and 0.95 times as broad as head; punctation slightly finer than that of head; impunctate midline rather broad; interstices without microsculpture.

Elytra ( Fig. 16 ) 0.55 times as long as pronotum, weakly dilated posteriad; humeral angles moderately marked; punctation moderately dense and shallow, weakly defined. Hind wings completely reduced.

Abdomen approximately 1.1 times as broad as elytra; punctation fine and shallow, moderately dense on tergites III–VI, sparser on tergites VII–VIII; interstices with shallow transverse microsculpture composed of isodiametric and short transverse meshes; posterior margin of tergite VII without palisade fringe.

: protarsomeres I–IV strongly dilated; tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 17 ) moderately strongly transverse, approximately 1.5 times as broad as long, with rather indistinct postero-median impression, pubescence not distinctly modified, posterior margin weakly concave; sternite VIII ( Fig. 18 ) transverse, approximately 1.1 times as broad as long, posterior excision of nearly semi-circular shape, pubescence not distinctly modified; aedeagus ( Figs 19–20 ) 0.83 mm long and symmetric, dorso-ventrally somewhat flattened; ventral process flat, gradually tapering apicad and apically acute in ventral view; dorsal plate with apical portion lamellate, moderately sclerotized, and multisinuate in lateral view, basal portion short and lamellate; internal sac with long dark membranous structure.

: unknown.

Comparative notes: Primarily based on the nearly unmodified pubescence of the male sternites VII and VIII, as well as on the dorso-ventrally flattened aedeagus with a long membranous structure in the internal sac, L. undosum is tentatively assigned to the L. discissum group, which previously included three described species from eastern Nepal and West Bengal. However, unlike the previously described representatives of this group, the aedeagus of L. undosum has a long dorsal plate. This species is readily distinguished from the species of all other Himalayan species groups by the absence of microsculpture on the head and by the distinctive morphology of the aedeagus.

Distribution and natural history: The type locality is situated in Solu Khumbu, eastern Nepal, some 120 km to the east of Kathmandu. The holotype was collected at an altitude between 3500–3800 m.

Figures

Figs 12–20: Lathrobium kiruense spec. nov. (12–15) and L. undosum spec. nov. (16–20): forebody (12–16); male sternite VII (13, 17); male sternite VIII (14, 18); aedeagus in lateralview (15, 19); aedeagus in ventral view (20). Scale bars: 12, 16: 1.0 mm; 13–15, 17–20: 0,5 mm.