Lathrobium latilobatum, Assing, 2017

Assing, Volker, 2017, Four new species and additional records of Lathrobium from Nepal and China (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 285-297 : 291-292

Lathrobium latilobatum nov.sp. ( Figs 9-16 )

T y p e m a t e r i a l: Holotype 3: "E-NEPAL, Kongma Danda, S of Kongma, 3200 m, 27°38'45''N, 87°12'40''E, 14.V.2015, leg. J. Schmidt / Holotypus 3 Lathrobium latilobatum sp.n., det. V. Assing 2016 " (NME). Paratypes: 333, 4♀♀: same data as holotype (NME, cAss).

E t y m o l o g y: The specific epithet (adjective) alludes to the stout base of the ventral process of the aedeagus both in lateral and in ventral view.

D e s c r i p t i o n: Size with evident sexual dimorphism. Body length 7.3-8.0 mm (3), 6.7-6.8 mm (♀); length of forebody 3.2-3.5 mm (3), 2.9-3.0 mm (♀). Other external characters ( Figs 9-10 ) as in L. kongmaicum .

3: protarsomeres I-IV ( Fig. 9 ) strongly dilated; tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 11 ) strongly transverse, approximately 1.75 times as broad as long, in the middle with impression with numerous moderately modified black setae, posterior margin distinctly, broadly concave; sternite VIII ( Fig. 12 ) approximately 1.13 times as broad as long, narrowly and deeply impressed along middle, on either side of middle with an oblong cluster of very dense moderately modified setae, posterior margin with shallow median excision; aedeagus ( Figs 13-14 ) approximately 1.25 mm long; ventral process symmetric, basally broad in lateral and in ventral view, weakly narrowed in subapical portion and apically not distinctly acute in ventral view; dorsal plate with lamellate, moderately long, and moderately sclerotized apical portion and without evident basal portion; internal sac with dark membranous structures, but without sclerotized spines.

♀: protarsomeres I-IV moderately dilated; posterior margin of tergite VIII obtusely pointed in the middle; sternite VIII ( Fig. 15 ) approximately 1.15 times as long as broad, with micropubescence in apical portion, posterior margin convexly produced in the middle; tergite IX ( Fig. 16 ) with very short antero-median portion with median suture, postero-lateral processes of moderate length; tergite X ( Fig. 16 ) very long and strongly convex in cross-section, slightly more than four times as long as antero-median portion of tergite IX.

C o m p a r a t i v e n o t e s: Like L. kongmaicum , L. latilobatum belongs to the L. nepalense group. Regarding the shape of the ventral process of the aedeagus, it is most similar to L. retunsum ASSING, 2016 (East Nepal: Solu Khumbu; female unknown), from which it is distinguished by the strongly modified chaetotaxy of the male sternites VII and VIII (practically unmodified in L. retunsum ), a more transverse male sternite VII with a more distinctly concave posterior margin, the median excision of the posterior margin of the male sternite VIII, and a longer aedeagus ( L. retunsum : 1.05 mm) with a longer, much less strongly curved (lateral view), and apically not truncate (ventral view) ventral process. It differs from the syntopic L. kongmaicum by slightly larger size of the male, a moderate sexual dimorphism of body size, a more transverse male sternite VII with a more distinctly concave posterior margin, and with shorter, more numerous, and more distinctly modified setae in the median impression, by a male sternite VIII with a more narrowly non-pubescent middle and a posterior margin with a median excision, by a distinctly larger aedeagus with a ventral process of completely different shape, and by medially slightly longer female tergite IX with a median suture. For illustrations of L. retunsum and other species of the L. nepalense group see ASSING (2012, 2013b, 2014, 2016).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The type locality is situated near Kongma, Kongma Danda, East Nepal. The specimens were collected at an altitude of 3200 m.

Figures

Figs 9-16: Lathrobium latilobatum nov.sp.: (9) male forebody; (10) head in lateral view; (11) male sternite VII; (12) male sternite VIII; (13-14) aedeagus in lateral and in ventral view; (15) female sternite VIII; (16) female abdominal segments IX-X. Scale bars: 9: 1.0 mm; 10-16: 0.5 mm.