Lathrobium latibasale, 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 : 10-11

Lathrobium latibasale sp. n.

( Figs 38–44 , Map 1 )

Type material: Holotype : “ NEPAL oc. Distr. Jumla, Gothichaur Khola, SE, 10.VI.1997, 3400–3600 m, Rhododend. Buschzone, leg. A. Weigel GSB / Holotypus  Lathrobium latibasale sp. n., det. V. Assing 2013” ( NME) . Paratypes: 2 , 3 : same data as holotype ( NME, cAss) .

Etymology: The specific epithet is an adjective composed of the Latin adjectives latus (broad) and basalis (basal) and alludes to the broad base of the ventral process (ventral view), the character best distinguishing this species from the similar L. fodens .

Description: Body size sexually dimorphic: body length in  6.4–6.8 mm, in  5.3–6.2 mm; length of forebody in  2.8–3.0 mm, in  2.5–2.7 mm. Habitus as in Fig. 36 . External characters ( Figs 36–37 ) as in L. fodens .

: protarsomeres I–IV moderately dilated; posterior margin of tergite VIII convex; sternite VII ( Fig. 38 ) distinctly transverse, posterior margin with relatively shallow bisinuate median excision, margin of this excision with comb of approximately 30 long pectinate setae, anterior to this comb with cluster of numerous stout black setae ( Fig. 39 ); sternite VIII ( Fig. 40 ) weakly transverse and with shallow impression in posteromedian portion, middle of this impression and anterior portion of sternite without pubescence, remainder of sternite with sparse pubescence, posterior excision of almost semi-circular shape; aedeagus ( Figs 41–42 ) approximately 1.25 mm long, symmetric; ventral process with broad base (ventral view) and apically shaped like a long straight sting; dorsal plate broad and short, in lateral view curved; internal sac without sclerotized structures.

: protarsomeres I–IV moderately dilated, slightly less so than in male; posterior margin of tergite VIII weakly convex; sternite VIII ( Fig. 43 ) approximately 1.1 times as long as broad, sparsely pubescent, and with strongly convex posterior margin; tergite IX ( Fig. 44 ) undivided in the middle and with moderately long, apically acute postero-lateral processes; tergite X ( Fig. 44 ) flat, of oval shape, and indistinctly longer than antero-median portion of tergite IX.

Comparative notes: As can be inferred from the highly similar external and sexual characters, L. latibasale is the adelphotaxon of L. fodens of the L. pectinatum group, which too is distributed in Jumla District. The new species is reliably distinguished from L. fodens only by the morphology of the aedeagus (base of ventral process broader in ventral view).

Distribution and natural history: The type locality is situated in Jumla District, Karnali Province, West Nepal ( Map 1 ). The specimens were collected in the rhododendron shrub zone at an altitude of 3400–3600 m.

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 30–45: Lathrobium rude sp. n. (30–35), L. latibasale sp. n. (36–44) and L. ascendens sp. n. (45): habitus (30, 36); forebody (31, 37); male sternite VII (32, 38); male sternite VIII (33, 40); aedeagus in lateral and in ventral view (34–35, 41–42); posteromedian portion of male sternite VII (39); female sternite VIII (43); female tergites IX–X (44–45). Scale bars: 30–31, 36–37: 1.0 mm; 32–35, 38, 40–45: 0.5 mm; 39: 0.2 mm.