Lathrobium cornigerum, 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 : 46-48

Lathrobium cornigerum sp. n.

( Figs 98-102 )

Type material:

Holotype : “ CHINA: JIANGXI prov., Wuyi Shan Nat. Res., Huangganshan [sic], (1800-2050 m), 5.vi.2001, Hlaváč & Cooter lgt / Holotypus  Lathrobium cornigerum sp. n., det. V. Assing 2012” (cAss).

Etymology:

The specific epithet (Latin, adjective: with antlers) alludes to the two apical horn-like processes of the dorsal plate of the aedeagus.

Description:

Large species of stout and somewhat depressed habitus; body length 12.0 mm; length of forebody 5.9 mm. Coloration: body black; legs and antennae dark-brown.

Head ( Fig. 98 ) distinctly transverse, 1.15 times as broad as long; punctation moderately coarse and moderately dense, sparse in median dorsal portion; interstices with distinct fine microreticulation, with subdued shine. Eyes rather large, slightly less than half as long as postocular region in dorsal view and composed of distinctly more than 50 ommatidia. Antenna 3.1 mm long.

Pronotum ( Fig. 98 ) broad, 1.12 times as long as broad and 1.05 times as broad as head; punctation distinctly coarser than that of head; impunctate midline narrow; interstices without microsculpture.

Elytra ( Fig. 98 ) very short, 0.47 times as long as pronotum; punctation rather coarse and defined.

Abdomen with very fine and moderately dense punctation, that of tergite VII somewhat sparser than that of anterior tergites; microsculpture fine and shallow, interstices rather glossy; posterior margin of tergite VII without palisade fringe.

: protarsomeres I-IV strongly dilated; tergite VIII with weakly convex posterior margin; sternites III-VI unmodified; sternite VII ( Fig. 99 ) strongly transverse, median impression extensive, of triangular shape, and with numerous strongly modified, very short black setae, posterior margin broadly concave; sternite VIII ( Fig. 100 ) distinctly transverse, weakly asymmetric, with extensive, pronounced, and weakly asymmetric median impression, this impression with numerous strongly modified, very short black setae, posterior excision rather shallow, slightly asymmetric, and distinctly bisinuate; aedeagus ( Figs 101-102 ) 2.0 mm long, strongly asymmetric, and of highly distinctive morphology; ventral process asymmetric and stout, subapically curved, and apically acute in lateral view; dorsal plate with apical portion strongly sclerotized, asymmetric, apically with a long right and a short left process, basal portion thin, lamellate, weakly sclerotized, and approximately as long as apical portion; internal sac with sclerotized apical structure, a large dark and sickle-shaped basal structure and with smaller membranous basal structure.

: unknown.

Comparative notes:

Lathrobium cornigerum is readily distinguished from all geographically close congeners by its external characters alone, especially its large size, the strongly transverse head, and the weakly oblong pronotum. In addition, it is characterized by the distinctive male sexual characters. Apart from the conspicuously short and dense short setae of the male sternite VIII, which are present also in L. fortepunctatum , possible synapomorphies linking L. cornigerum to other species recorded from China were not found.

Distribution and natural history:

The species is most likely endemic to the Wuyi Shan. The holotype was collected in the Huanggang Shan in Jiangxi province at an altitude of 1800-2050 m, together with Lathrobium depravatum and L. wuyicum .

Figures

Figs 97-102: Lathrobium depravatum sp. n. (97) and L. cornigerum sp. n. (98-102): female sternite VIII (97); forebody (98); male sternite VII (99); male sternite VIII (100); aedeagus in lateral and in ventral view (101-102). Scale bars: 98: 1.0 mm; 97, 99-102: 0.5 mm.