Lathrobium retunsum, Assing, 2016

Assing, Volker, 2016, Six new species, a new name, and additional records of Lathrobium from the Palaearctic region (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 48 (1), pp. 191-210 : 198-199

Lathrobium retunsum nov.sp. ( Figs 10-14 )

T y p e m a t e r i a l: Holotype 3: " NEPAL Solu Khumbu , Taktor to Lamjura Pass, 3350- 3450 m, 28.V.2013, leg. J. Schmidt, 27°34'37''N 86°30'07''E / Holotypus 3 Lathrobium retunsum nov.sp., det. V. Assing 2015 " ( NME).

E t y m o l o g y: The specific epithet (Latin, adjective: blunt, obtuse) alludes to the apically truncate (ventral view) ventral process of the aedeagus.

D e s c r i p t i o n: Body length 6.5 mm; length of forebody 3.3 mm. Coloration: body blackish-brown with the abdominal apex slightly paler brown; legs and antennae darkbrown.

Head ( Fig. 10 ) 1.05 times as broad as long; punctation rather coarse and moderately dense, sparser in anterior and median dorsal portions; interstices with distinct microreticulation. Eyes moderately small, slightly less than half as long as postocular region in dorsal view, and composed of approximately 50 ommatidia. Antenna 1.8 mm long.

Pronotum ( Fig. 10 ) 1.13 times as long as broad and 1.06 times as broad as head; punctation similar to that of head; interstices with distinct microreticulation.

Elytra ( Fig. 10 ) 0.53 times as long as pronotum; humeral angles weakly marked; punctation shallow and ill-defined; interstices without microsculpture. Hind wings completely reduced.

Abdomen broader than elytra; punctation moderately fine and dense, somewhat less dense on tergites VII and VIII than on anterior tergites; interstices with fine microsculpture; posterior margin of tergite VII without palisade fringe; posterior margin of tergite VIII obtusely pointed in the middle.

3: protarsomeres I-IV strongly dilated ( Fig. 10 ); sternite VII ( Fig. 11 ) strongly transverse, approximately 1.65 times as broad as long, shallowly impressed in postero-median portion, this impression with very weakly modified setae, posterior margin broadly concave; sternite VIII ( Fig. 12 ) 1.2 times as broad as long, weakly impressed along middle, pubescence not distinctly modifed, posterior margin shallowly concave in the middle; aedeagus ( Figs 13-14 ) 1.05 mm long; ventral process evenly curved in lateral view and apically broadly truncate in ventral view; dorsal plate with lamellate, long, and weakly sclerotized apical portion and without distinct basal portion; internal sac with dark membranous structures, but without sclerotized spines.

♀: unknown.

C o m p a r a t i v e n o t e s: As can be inferred from the external (head and pronotum with distinct microsculpture), as well as the male sexual characters (shapes and chaetotaxy of sternites VII and VIII; morphology of the aedeagus), L. retunsum belongs to the L. nepalense group (see ASSING 2012b), which is represented in the Himalaya, particularly in Central Nepal, by numerous species. Among the few species known from East Nepal, L. retunsum is similar to L. makaluicum , but differs by slightly larger body size, unmodified pubescence of the male sternites VII and VIII (distinctly modified in L. makaluicum ), and by the morphology of the aedeagus ( L. makaluicum : ventral process weakly angled in lateral view, much more slender and apically more acute in ventral view; dorsal plate with distinct basal portion). For illustrations of L. makaluicum see ASSING (2013b), for figures of other species of the L. nepalense group see ASSING (2012b, 2014).

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 in Solukhumbu District, East Nepal. The holotype was collected at an altitude of approximately 3400 m.

Figures

Figs 8-14: Lathrobium makaluicum ASSING (8-9) and L. retunsum nov.sp. (10-14): (8) female sternite VIII; (9) female abdominal segments IX-X; (10) forebody; (11) male sternite VII; (12) male sternite VIII; (13-14) aedeagus in lateral and in ventral view. Scale bars: 10: 1.0 mm; 8-9, 11- 14: 0.5 mm.