Lathrobium uttaricum, Assing, 2013

Assing, V., 2013, Six new species and additional records of Lathrobium from the Palaearctic region, Linzer biologische Beiträge 45 (1), pp. 247-266 : 258-260

Lathrobium uttaricum nov.sp.

( Figs 21-29 , Map 2 )

Type material: Holotype ♂: " N-India: Uttaranchal state, ca. 30 km N Bageshwar, SE Dakhuri vill. [= Dhakuri ; ca. 30°05'N, 79°55'E], 2600-2800 m, 25.- 26.6.2003, leg. Z. Kejval & M. Trýzna / Holotypus ♂ Lathrobium uttaricum sp. n., det. V. Assing 2013" ( NHMW) . Paratypes: 2♂♂, 3♀♀: same data as holotype ( NHMW, cAss) .

Etymology: The specific epithet is derived from the name of the state where the type locality is situated and where this species is currently the sole representative of the genus.

Description: Species with weakly pronounced sexual size dimorphism; body length 6.8-7.5 mm (♂), 6.5-7.2 (♀); length of forebody 3.4-3.6 mm (♂), 3.1-3.2 mm (♀). Habitus as in Fig. 21 . Coloration: whole body, including appendages, reddish.

Head ( Fig. 22 ) approximately 1.05 times as broad as long; posterior angles marked; punctation moderately coarse and rather dense, slightly sparser in median dorsal portion; interstices with distinct microreticulation, on average somewhat broader than diameter of punctures. Eyes small, not projecting from lateral contours of head, approximately 1/5 the length of postocular region in dorsal view and composed of approximately 15 ommatidia.

Pronotum ( Fig. 22 ) approximately 1.25 times as long as broad and 0.95 times as broad as head; lateral margins weakly concave anteriorly in dorsal view; punctation similar to that of head, or slightly finer; interstices without microsculpture.

Elytra ( Fig. 22 ) moderately short, approximately 0.6 times as long as pronotum; humeral angles weakly marked; punctation fine and shallow; interstices without distinct microsculpture. Hind wings completely reduced. Metatibia slightly compressed. Protarsomeres with pronounced sexual dimorphism.

Abdomen approximately 1.1 times as broad as elytra; punctation fine and moderately dense, slightly sparser on posterior than on anterior tergites; posterior margin of tergite VII without palisade fringe; posterior margin of tergite VIII with weakly pronounced sexual dimorphism.

♂: protarsomeres I-IV strongly dilated; tergite VIII with weakly convex posterior margin; sternites IV and V weakly depressed in postero-median portion, these depressions with sparse, moderately modified black setae on either side of middle; sternite VI with shallow median impression, this impression with sparse, moderately modified black setae; sternite VII ( Fig. 23 ) strongly transverse, median impression without setae in the middle, laterally with sparse, moderately modified black setae, posterior margin broadly concave; sternite VIII ( Fig. 24 ) distinctly transverse, with pronounced median impression, this impression without setae in the middle, laterally with rather sparse, moderately modified black setae, posterior margin concave, in the middle angularly produced; aedeagus ( Figs 25-26 ) approximately 1.6 mm long; ventral process slightly asymmetric, apically hooked in lateral view; dorsal plate moderately long, flat, and apically weakly convex in dorsal view, apical portion broad, not distinctly delimited from basal portion; internal sac with three pairs of distinctly sclerotized spines, one pair of very long spines, one of intermediate length, and one of rather short spines.

♀: protarsomeres I-IV rather weakly dilated; posterior margin of tergite VIII ( Fig. 27 ) weakly angular in the middle; sternite VIII ( Fig. 28 ) strongly oblong and with strongly convex posterior margin; tergite IX with long and undivided antero-median portion and short postero-lateral processes; tergite X very weakly convex in cross-section and very short, shorter than antero-median portion of tergite IX ( Fig. 29 ).

Comparative notes: The external and sexual characters do not suggest closer phylogenetic affiliations to any of the previously known species groups represented in the Himalaya. Lathrobium uttaricum shares the pale coloration, strongly reduced eyes, the general shape of the ventral process of the aedeagus, and the morphology of the female tergites IX and X with the species of the L. deuvei group, but differs from them by numerous characters (e.g., head shape, eyes composed of more ommatidia, presence of a sexual size dimorphism, sexual dimorphism of tergite VIII, shapes and chaetotaxy of the male sternites VII and VIII, modified male sternites IV-VI, the asymmetric aedeagus, the shapes of the dorsal plate and internal structures of the aedeagus, and the shape of the female sternite VIII). Moreover, the species of the L. deuvei group are all confined to high-altitude habitats above 4000 m. These observations suggest that L. uttaricum represents a species group of its own, characterized by a sexual size dimorphism (unique among Himalayan Lathrobium ), reduced eyes composed of approximately 15 ommatidia, reddish coloration, moderate body size, a pronounced sexual dimorphism of protarsomeres I-IV, a sexual dimorphism of tergite VIII, modified male sternites IV-VI (unique among Himalayan Lathrobium ), the absence of modified setae in the middle of the male sternites IV-VIII, an asymmetric aedeagus with three pairs of sclerotized spines in the internal sac, a broad and apically weakly convex, not distinctly delimited apical portion of the dorsal plate, a strongly oblong female sternite VIII, and an undivided antero-median portion of the female tergite IX.

Distribution and natural history: The type locality is situated to the north of Bageshwar in Uttaranchal state, North India ( Map 2 ). The specimens were collected at an altitude of 2600-2800 m.

Figures

Map 2: Type localities of Lathrobium uttaricum nov.sp. (triangle), L. hartmanni nov.sp. (circle), and L. makaluicum nov.sp. (diamond).

Figs 21-29: Lathrobium uttaricum nov.sp.: (21) habitus; (22) forebody; (23) male sternite VII; (24) male sternite VIII; (25-26) aedeagus in lateral and in ventral view; (27) posterior portion of female tergite VIII; (28) female sternite VIII; (29) female tergites IX-X. Scale bars: 21-22: 1.0 mm; 23-29: 0.5 mm.