Lathrobium spinans, 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 : 200-201

Lathrobium spinans nov.sp. ( Figs 23-29 )

T y p e m a t e r i a l: Holotype 3: " NEPAL, Manaslu Mts., N slope, above Prok, 28°30'N, 84°49'E, 2950-3400 m, 27.V.2006, leg. J. Schmidt / Holotypus 3 Lathrobium spinans nov.sp., det. V. Assing 2015 " (NME). Paratypes: 2♀♀: same data as holotype (NME, cAss).

E t y m o l o g y: The specific epithet is the present participle of the Latin verb spinare (to sting) and alludes to the spine-shaped ventral process of the aedeagus (ventral view).

D e s c r i p t i o n: Body length 4.7-5.4 mm; length of forebody 2.3-2.5 mm. Coloration: forebody reddish; abdomen reddish-brown to brown; legs pale-reddish to yellowish-brown; antennae dark-reddish.

Head ( Fig. 23 ) 1.03-1.07 times as long as broad; punctation moderately coarse and moderately dense, slightly less dense in median dorsal portion; interstices with microreticulation. Eyes not projecting from lateral contours of head, very small, less than 0.2 times as long as postocular region in dorsal view, and composed of barely 10 ommatidia. Antenna 1.2-1.3 mm long.

Pronotum ( Fig. 23 ) approximately 1.25 times as long as broad and approximately as broad as head; punctation moderately dense, finer than that of head; interstices without microsculpture.

Elytra ( Fig. 23 ) short, approximately 0.55 times as long as pronotum; humeral angles weakly marked; punctation shallow and ill-defined; interstices without microsculpture. Hind wings completely reduced. Protarsomeres I-IV with, femora and tibiae without sexual dimorphism.

Abdomen slightly broader than elytra; punctation distinct and moderately dense; interstices with fine microsculpture; posterior margin of tergite VII without palisade fringe; posterior margin of tergite VIII weakly convex.

3: protarsomeres I-IV strongly dilated ( Fig. 23 ); sternite VII ( Fig. 24 ) strongly transverse, with unmodified pubescence, and with broadly and distinctly concave posterior margin; sternite VIII ( Fig. 25 ) oblong, 1.08 times as long as broad, with unmodified pubescence, and with rather deep and broad posterior excision; aedeagus ( Figs 26-27 ) 0.75 mm long, symmetric, and dorso-ventrally flattened; ventral process apically distinctly spine-shaped; dorsal plate broad, short, and apically truncate.

♀: protarsomeres I-IV dilated, but distinctly less so than in male; sternite VIII ( Fig. 28 ) approximately 1.2 times as long as broad and with evenly convex posterior margin; tergite IX ( Fig. 29 ) undivided in the middle, postero-lateral processes short, only slightly extending beyond apex of tergite X; tergite X ( Fig. 29 ) weakly convex in cross-section and approximately 1.35 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: Based on external character (small body size, small eyes, pale coloration) and particularly the shape of the aedeagus (dorso-ventrally flattened; ventral process apically spine-shaped, dorsal plate short and broad), L. spinans belongs to the L. pectinatum group (see ASSING 2012b), the most speciose species group in Nepal. In the vast majority of the species of the L. pectinatum group, the chaetotaxy of at least the male sternite VII is strongly modified (with one or more combs of palisade setae); moreover, many species have sexually dimorphic femora or tibiae. The only geographically close species without such conspicuous modifications are L. aculeatum COIFFAIT, 1982 (Dhaulagiri range) and L. spiculatum ASSING, 2012 , an endemic of the Langtang region. The new species is readily distinguished from both of them by the much broader aedeagus with a much shorter ventral process. For illustrations of L. aculeatum , L. spiculatum , and other species of the L. pectinatum 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 the northern Manaslu range. The specimens were sifted at an altitude between 2950 and 3400 m.

Figures

Figs 23-29: Lathrobium spinans nov.sp.: (23) forebody; (24) male sternite VII; (25) male sternite VIII; (26-27) aedeagus in lateral and in ventral view; (28) female sternite VIII; (29) female abdominal segments IX-X. Scale bars: 23: 1.0 mm; 24-25, 28-29: 0.5 mm; 26-27: 0.2 mm.