Lathrobium eques, 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

Lathrobium eques sp. n.

( Figs 46–55 , Map 1 )

Type material: Holotype : “ NEPAL oc. Distr. Jumla, 3 km E Churta, Waldw. , 29°10'53"N, 82°28'00"E, 06.VI.1997 3400 m, leg. A. Weigel GSB / Holotypus  Lathrobium eques sp. n., det. V. Assing 2013” ( NME).

Paratypes: 1 , 1 : same data as holotype ( NME, cAss) .

Etymology: The specific epithet (Latin, noun: horseman, equestrian) alludes to the spur-like modifications of the male metafemora.

Description: Body length 5.3–5.8 mm; length of forebody 2.6–2.9 mm. Habitus as in Fig. 46 . Coloration: whole body, including appendages, reddish.

Head ( Fig. 47 ) 1.02–1.07 times as long as broad; punctation sparse and moderately coarse; interstices much broader than diameter of punctures, with distinct microreticulation. Eyes small, composed of approximately 10 ommatidia, one-sixth to one-fifth as long as postocular region in dorsal view. Antenna 1.4–1.5 mm long.

Pronotum ( Fig. 47 ) 1.20–1.25 times as long as broad and about as broad as head; posterior margin concave; punctation similar to that of head; midline broadly impunctate; interstices without microsculpture.

Elytra ( Fig. 47 ) rather broad and approximately 0.6 times as long as pronotum; punctation fine and sparse; interstices without distinct microsculpture. Hind wings completely reduced. Protarsomeres I–IV and metafemora with distinct sexual dimorphism.

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 with a pronounced spur-like posterior extension at apical third ( Fig. 48 ); sternite VII ( Fig. 49 ) moderately transverse, with median impression, on either side of this impression with a cluster of stout black setae posteriorly, posterior excision of transversely trapezoid shape, margin of the excision with a comb of 25–30 stout palisade setae; sternite VIII ( Fig. 50 ) approximately as long as broad, in median portion extensively without pubescence, posterior excision moderately deep, lateral margins of this excision with a row of dense short setae; aedeagus ( Figs 51–52 ) approximately 0.95 mm long, dorso-ventrally somewhat flattened; ventral process basally broad, apically asymmetric and nearly stingshaped; dorsal plate short, basally broad, and apically with a sting-like extension ( Fig. 53 ); internal sac with membranous structures.

: protarsomeres I–IV moderately dilated; metafemur with weakly pronounced posterior convexity at apical third; sternite VIII ( Fig. 54 ) nearly 1.2 times as long as broad, with convex posterior margin; tergite IX ( Fig. 55 ) undivided in the middle, postero-lateral processes short, only slightly extending beyond apex of tergite X; tergite X ( Fig. 55 ) flat, of oval shape, and approximately 1.6 times as long as antero-median portion of tergite IX.

Comparative notes: The similarly modified male sexual characters (modifications of metafemora; shapes and chaetotaxy of sternites VII–VIII; similarly shaped, asymmetric ventral process of the aedeagus) suggest that L. eques represents the adelphotaxon of L. calcaratum , from which it is distinguished only by the less broad posterior excision of the male sternite VII, the slightly less deep posterior excision of the male sternite VIII, and by the morphology of the aedeagus (apical portion of ventral process much more slender; ventral process of different shape also in lateral view). For illustrations of L. calcaratum see ASSING (2012).

Distribution and natural history: The type locality is situated in Jumla District, Karnali Province, West Nepal ( Map 1 ), at an altitude of 3400 m. The material was collected together with a male of L. fodens .

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.