Lathrobium equitans, Assing, 2014

Assing, Volker, 2014, New species and records of Lathrobium from the Palaearctic region, primarily from Nepal (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 64 (1), pp. 1-28 : 12-14

Lathrobium equitans sp. n.

( Figs 56–61 , Map 1 )

Type material: Holotype : “ NEPAL, N. Dhorpatan, Porkapan, 1977, P. Morvan / Holotypus  Lathrobium equitans sp. n., det. V. Assing 2013” (cRou).

Paratypes: 2 : same data as holotype (cRou, cAss).

Etymology: The specific epithet is the present participle of the Latin verb equitare (to ride) and alludes to the spur-like modifications of the male metafemora.

Description: Body length 4.8–5.2 mm; length of forebody 2.4–2.5 mm. Habitus similar to that of L. eques . Coloration: whole body, including appendages, reddish.

Head approximately as long as broad; punctation sparse and rather fine to moderately coarse; interstices much broader than diameter of punctures, with distinct microreticulation. Eyes small, composed of approximately 10 ommatidia, approximately one-sixth as long as postocular region in dorsal view. Antenna 1.4 mm long.

Pronotum 1.20–1.25 times as long as broad and about as broad as head; posterior margin distinctly concave; punctation denser and slightly coarser than that of head; midline broadly impunctate; interstices without microsculpture.

Elytra approximately 0.6 times as long as pronotum; punctation fine and sparse; interstices without distinct microsculpture. Hind wings completely reduced. Male metafemora and metatibiae conspicuously modified.

Abdomen approximately as broad as elytra; punctation distinct and moderately dense; interstices with shallow microsculpture; posterior margin of tergite VII without palisade fringe; posterior margin of tergite VIII convex.

: protarsomeres I–IV strongly dilated; metafemur compressed, strongly dilated posteriorly, and with a pronounced spur-like posterior extension ( Fig. 56 ); metatibia strongly dilated in apical two-thirds, compressed, and excavate on inner side ( Fig. 56 ); sternite VII ( Fig. 57 ) distinctly transverse and with median impression, this impression with moderately dense black setae, posterior margin concavely excised in the middle, this excision with comb of approximately 40 palisade setae; sternite VIII ( Fig. 58 ) approximately as long as broad and sparsely pubescent, posterior excision moderately deep, lateral margins of this excision with a row of dense short setae; aedeagus ( Figs 59–60 ) approximately 0.85 mm long, dorso-ventrally somewhat flattened, and nearly symmetric; ventral process broad and apically sting-shaped; dorsal plate short, broad, and apically convex in dorsal view ( Fig. 61 ); internal sac with membranous structures.

: unknown.

Comparative notes: Among the species of the L. pectinatum group, L. equitans is readily identified based on the conspicuous modifications of the male metafemora and metatibiae, on the shapes and chaetotaxy of the male sternites VII and VIII, as well as on the morphology of the aedeagus. The similarly modified male metafemora suggest that it is closely allied to L. calcaratum and L. eques . For illustrations of other species of the L. pectinatum group see ASSING (2012).

Distribution and natural history: The type locality is situated in the Dhaulagiri range in central Nepal ( Map 1 ). Additional data are not available.

Figures

Map 1: Distributions of Lathrobium species in Nepal: L. semicirculatum (white triangles), L. constrictum (black triangle), L. descendens (white circles), L. ascendens (black circle), L. rude (white star), L. latibasale (black star), L. eques (white diamond), L. equitans (black diamond), L. abruptum (black square), L. kemum (white square).

Figs 46–61: Lathrobium eques sp. n. (46–55) and L. equitans sp. n. (56–61): male habitus (46); forebody (47); male metafemur (48, 56); male sternite VII (49, 57); male sternite VIII (50, 58); aedeagus in lateral and in ventral view (51–52, 59–60); dorsal plate of aedeagus in dorsal view (53, 61); female sternite VIII (54); female tergites IX–X (55). Scale bars: 46–47: 1.0 mm; 48–52, 54–60: 0.5 mm; 53, 61: 0.2 mm.