Lathrobium sexocellatum, 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 : 263-265

Lathrobium sexocellatum nov.sp.

( Figs 38-42 )

Type material: Holotype ♂: " CHINA: Yunnan, Nujiang Lisu Pref., Gaoligong Shan , "Cloud Pass", 21 km NW Liuku, 3150 m, 25°58'21''N, 98°41'01''E, shrubs & bamboo, litter sifted, 3.IX.2009, leg. M. Schülke [CH09-22a] / Holotypus ♂ Lathrobium sexocellatum sp.n., det. V. Assing 2013" ( cAss).

Etymology: The specific epithet (Latin, adjective) alludes to the conspicuously small eyes, which are composed of only six ommatidia.

Description: Species of rather small size; body length 6.3 mm; length of forebody 3.0 mm. Coloration: body pale-reddish; legs and antennae yellowish-red.

Head ( Fig. 38 ) 1.06 times as long as broad; punctation rather coarse and very dense, only slightly sparser in postero-median dorsal portion; interstices with shallow microreticulation, narrower than diameter of punctures. Eyes weakly projecting from lateral contours of head, reduced to minute rudiments and composed of 6 ommatidia. Antenna 1.75 mm long.

Pronotum ( Fig. 38 ) 1.3 times as long as broad and 0.96 times as broad as head; punctation similar to that of head, very dense; impunctate midline very narrow; interstices without microsculpture, narrower than diameter of punctures.

Elytra ( Fig. 38 ) short, approximately 0.58 times as long as pronotum; humeral angles weakly marked; punctation shallow, fine, and moderately dense; interstices without microsculpture. Hind wings completely reduced.

Abdomen broader than elytra; punctation fine and moderately dense; interstices glossy, with very shallow microsculpture; posterior margin of tergite VII without palisade fringe.

♂: protarsomeres I-IV moderately dilated; tergite VIII with very weakly convex, almost truncate posterior margin; sternite VII ( Fig. 39 ) strongly transverse, posteriorly with shallow, but rather extensive median impression, this impression with weakly modified dark setae, posterior margin broadly and weakly concave; sternite VIII ( Fig. 40 ) transverse, with cluster of dense, weakly modified black setae on either side of middle, posterior excision almost V-shaped and in asymmetric position; aedeagus ( Figs 41-42 ) large in relation to body size, 1.3 mm long; ventral process symmetric in ventral view, narrowed apicad, and almost acute apically; dorsal plate of highly distinctive morphology, apical portion very long, apically spear-shaped in lateral view, subapically with distinct toothlike process, basal portion lamellate and very short; internal sac with long membranous structure, with subapical cluster of moderately sclerotized thin spines, and with relatively long and weakly slcerotized apical spine.

♀: unknown.

Comparative notes: Lathrobium sexoculatum is readily distinguished from all other congeners known from Yunnan by the extremely small eyes. Like L. sufflatum , it probably belongs to the L. fortehamatum subgroup, as is suggested by external (reddish coloration, strongly reduced eyes) and by the male sexual characters (shape and chaetotaxy of the male sternite VII, the somewhat asymmetric and almost V-shaped posterior excision of the male sternite VIII, the shape of the ventral process of the aedeagus, the long apical portion of the dorsal plate, and the presence of a spine in the internal sac). The species is distinguished from the syntopic L. sufflatum not only by the completely different male sexual characters and the much smaller eyes, but also by larger body size, the much more slender pronotum (in relation to head), the much denser punctation of head and pronotum, the narrowly impunctate midline of the pronotum, the longer elytra, as well as by the much sparser punctation and the indistinct microsculpture of the abdomen.

Distribution and natural history: The type locality and the circumstances of collection are identical to those of L. sufflatum .

Figures

Figs 38-42: Lathrobium sexoculatum nov.sp.: (38) forebody; (39) male sternite VII; (40) male sternite VIII; (41) aedeagus in lateral view; (42) apical portion of aedeagus in lateral view. Scale bars: 38: 1.0 mm; 39-41: 0.5 mm; 42: 0.2 mm.