Lathrobium parvitergale, Assing, 2013

Assing, Volker, 2013, On the Lathrobium fauna of China III. New species and additional records from various provinces (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 63 (1), pp. 25-52 : 42-43

Lathrobium parvitergale sp. n.

( Figs 80-86 )

Type material:

Holotype : “ CHINA: Zhejiang [ CH 07-37], Tianmu Shan , pass 25 km NNW Linan, 620-820 m, 30°25'40"N, 119°35'30"E, creek valley with bamboo and mixed forest, litter, sifted, 16.VI.2007, M. Schülke / Holotypus  Lathrobium parvitergale sp. n., det. V. Assing 2012” (cAss) . Paratype : same data as holotype (cSch) .

Etymology:

The specific epithet (Latin, adjective) refers to the conspicuously small female tergite X.

Description:

Large species; body length 12.0 mm (), 11.5 mm (); length of forebody 5.5 mm (), 5.3 mm (). Coloration: body black; legs and antennae dark-brown.

Head ( Fig. 80 ) moderately transverse, approximately 1.05 times as broad as long; punctation moderately coarse, rather dense in lateral and posterior portions, rather sparse in median and anterior dorsal portions; interstices glossy, with very fine and very shallow microreticulation. Eyes relatively large, approximately half as long as postocular region in dorsal view and composed of approximately 50 weakly defined ommatidia. Antenna 3.0- 3.2 mm long.

Pronotum ( Fig. 80 ) rather short, approximately 1.15 times as long as broad and 1.08 times as broad as head; punctation similar to that of head; impunctate midline very narrow; interstices without microsculpture.

Elytra ( Fig. 80 ) short, approximately 0.52 times as long as pronotum; punctation dense, coarse, and rather defined. Hind wings completely reduced. Protarsi with rather weakly pronounced sexual dimorphism.

Abdomen with fine and dense punctation, that of tergite VII nearly as dense as that of anterior tergites; microsculpture fine and indistinct, visible only at high magnifications, interstices glossy; posterior margin of tergite VII without palisade fringe; tergite VIII without sexual dimorphism, posterior margin weakly convex in both sexes.

: protarsomeres I-IV strongly dilated; sternites III-VI unmodified; sternite VII ( Fig. 81 ) strongly transverse and with small and shallow median impression posteriorly, this impression with few modified short black setae, posterior margin broadly concave; sternite VIII ( Fig. 82 ) transverse, with oblong and somewhat asymmetric median impression, this impression posteriorly (anterior to posterior excision) with pronounced, defined, and asymmetric cluster of numerous distinctly modified, short and stout black setae; posterior exci- sion slightly asymmetric, rather deep and very narrow; aedeagus ( Figs 83-84 ) 1.7 mm long and asymmetric; ventral process stout, short, and apically asymmetrically bilobed; dorsal plate distinctly sclerotized, with long, large, somewhat asymmetric, and apically acute apical portion and with short lamellate basal portion; internal sac with long, stout, curved, and strongly sclerotized apical spine.

: protarsomeres I-IV distinctly dilated, but slightly less so than in male; posterior margin of sternite VIII ( Fig. 85 ) 1.7 mm long, weakly oblong, posterior margin distinctly and convexly produced in the middle; tergite IX with long, undivided median portion and with short postero-lateral processes; tergite X small, only approximately half as long as tergite IX in the middle ( Fig. 86 ).

Comparative notes:

This highly distinctive species is characterized particularly by its large size, dark coloration, and by the sexual characters, particularly the shape and chaetotaxy of the male sternite VIII, the morphology of the aedeagus (stout, short, and apically asymmetrically bilobed ventral process; shapes of dorsal plate and apical internal structure), the long median portion of the female tergite IX, and the conspicuously small female tergite X. It is distinguished from all other described species known from the Tianmu Shan and the adjacent Longwang Shan by its larger size alone. Lathrobium parvitergale shares the presence of an apical spine in the internal sac with most species from these mountain ranges, but the other sexual characters do not suggest closer phylogenetic affiliations with any of them. For illustrations of the described species recorded from Tianmu Shan and Longwang Shan see PENG et al. (2012a) and WATANABE (1999a, b).

Distribution and natural history:

The type locality is situated in the Tianmu Shan in Zhejiang province. The specimens were sifted from leaf litter in a mixed forest with bamboo at an altitude of 620-820 m.

Figures

Figs 80-86: Lathrobium parvitergale sp. n.: forebody (80); male sternite VII (81); male sternite VIII (82); aedeagus in lateral and in