Lathrobium curvaculeatum, 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 : 18-20

Lathrobium curvaculeatum sp. n.

( Figs 97–105 , Map 2 )

Type material: Holotype : “ NEPAL W Dhaulagiri, Thankurb 3250 m, 19.IX.2012, 28°36'32"N, 83°01'26"E, leg. J. Schmidt / Holotypus  Lathrobium curvaculeatum sp. n., det. V. Assing 2013” ( NME).

Paratypes: 2 , 2  [2 , 1  teneral]: same data as holotype ( NME, cAss) .

Etymology: The specific epithet is an adjective composed of the past participle of the Latin verb curvare (to curve) and the Latin adjective aculeatus (with a sting). It alludes to the curved sting-shaped apex of the ventral process of the aedeagus.

Description: Body length 4.8–6.4 mm; length of forebody 2.5–2.8 mm; females slightly smaller than males. Habitus as in Fig. 97 . Coloration: forebody dark-brown; abdomen blackish-brown; legs dark reddish-brown; antennae darkreddish.

Head ( Fig. 98 ) weakly oblong, approximately 1.04 times as long as broad; punctation moderately dense and moderately coarse, sparser in median dorsal portion; interstices with distinct microreticulation. Eyes small, composed of approximately 10 ommatidia, one-sixth to one-fifth as long as postocular region in dorsal view. Antenna 1.3–1.5 mm long.

Pronotum ( Fig. 98 ) approximately 1.25 times as long as broad and about as broad as head; punctation similar to that of head; midline broadly impunctate; interstices without microsculpture.

Elytra ( Fig. 98 ) approximately 0.6 times as long as pronotum; punctation fine and sparse; interstices without distinct microsculpture. Hind wings completely reduced. Protarsomeres I–IV with pronounced sexual dimorphism; metatibia distinctly compressed in apical two-thirds in both sexes ( Fig. 99 ); metafemora without sexual dimorphism.

Abdomen slightly broader than 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; sternite VII ( Fig. 100 ) strongly transverse, with extensive, but shallow median impression, in posterior portion with transverse cluster of numerous black setae, posterior margin with broad and shallow posterior excision, margin of this excision with a comb of approximately 30 long palisade setae; sternite VIII ( Fig. 101 ) approximately 1.2 times as broad as long, in anterior and median portion extensively without pubescence, posterior excision moderately deep, weakly asymmetric and of nearly semi-circular shape, lateral margins of this excision with a row of dense short setae; aedeagus ( Figs 102–103 ) approximately 1.2 mm long and weakly asymmetric; ventral process basally broad and apically extending into a long spine-shaped process, apex of this process noticeably curved to the left in ventral view; dorsal plate broad, short, and apically weakly convex; internal sac without appreciable structures.

: protarsomeres I–IV moderately dilated; sternite VIII ( Fig. 104 ) 1.1 times as long as broad, posteriorly distinctly, convexly produced; tergite IX ( Fig. 105 ) undivided in the middle, postero-lateral processes short, only slightly extending beyond apex of tergite X; tergite X ( Fig. 105 ) weakly convex in cross-section, of oval shape, and approximately 1.1 times as long as antero-median portion of tergite IX.

Comparative notes: Among the species of the L. pectinatum group with compressed metatibiae in both sexes, L. curvaculeatum is characterized by the relatively dark coloration, the shapes and chaetotaxy of the male sternites VII and VIII, and particularly by the shape of the ventral process of the aedeagus.

Distribution and natural history: The type locality is situated in the western Dhaulagiri range, Central Nepal ( Map 2 ), at an altitude of 3250 m.

Figures

Map 2:Distributions of Lathrobium species inNepal:L. flexaculeatum (white square),L. rectaculeatum (blackstar),L. curvaculeatum (white star), L. hebes (black square), L. imberbe (black triangle), L. plicatum (black diamond), L. calcaratum (circles; white circles: new records; black circle: type locality), L. fodens (white triangles), L. aculeatum (white diamonds).

Figs 97–114: Lathrobium curvaculeatum sp. n. (97–105) and L. hebes sp. n. (106–114): habitus (97, 106); forebody (98, 107); male metatibia (99); male sternite VII (100, 108); male sternite VIII (101, 109); aedeagus in lateral and in ventral view (102–103, 110–111); female sternite VIII (104, 113); female tergites IX–X (105, 114); apical portion of ventral process of aedeagus in ventral view (112). Scale bars: 97–98, 106–107: 1.0 mm; 99–105, 108–111, 113–114: 0.5 mm; 112: 0.2 mm.