Lathrobium pium, 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 : 50-51

Lathrobium pium sp. n.

( Figs 114-121 )

Type material:

Holotype : “ CHINA: Guizhou, Leishan Co., SE Kaili, NE Leishan, Leigong Shan , E-slope, 26°22.56'N, 108°13.40'E / ca. 300 m S of pass, 14./ 16.6.2001, ca. 1700 m, leg. Schillhammer (5) / Holotypus  Lathrobium pium sp. n., det. V. Assing 2013” ( NHMW) . Paratypes: 1, 1: same data as holotype ( NHMW, cAss) .

Etymology:

The specific epithet (Latin, adjective: pious) alludes to the shape of the aedeagus, which, in lateral view, somewhat reminds of a praying person.

Description:

Relatively large species; body length 9.0-10.0 mm; length of forebody 4.5-4.7 mm. Habitus as in Fig. 114 . Coloration: body blackish-brown to black; legs reddish-brown to dark-brown with paler tarsi; antennae dark-reddish.

Head ( Fig. 115 ) approximately as broad as long or weakly transverse; punctation moderately coarse, rather dense in lateral and posterior portion and sparse in median and anterior dorsal portion; interstices with fine and distinct microreticulation. Eyes moderately small, approximately 0.3 times as long as postocular region in dorsal view and with> 50 ommatidia. Antenna approximately 2.5 mm long. Pronotum ( Fig. 115 ) approximately 1.2 times as long as broad and about 1.05 times as broad as head; punctation somewhat coarser than that of head and moderately dense; impunctate midline rather narrow; interstices without microsculpture.

Elytra ( Fig. 115 ) approximately 0.52 times as long as pronotum, not particularly broad; punctation shallow and moderately dense. Hind wings completely reduced. Protarsomeres with moderately pronounced sexual dimorphism.

Abdomen slightly broader than elytra; punctation of tergites III-VI moderately dense, that of tergites VII-VIII somewhat sparser; interstices with shallow, but distinct microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII without sexual dimorphism, posterior margin distinctly convex in both sexes.

: protarsomeres I-IV strongly dilated; sternite VII ( Fig. 116 ) moderately transverse, with sparse and very weakly modified black setae in posterior median portion; sternite VIII ( Fig. 117 ) approximately as long as broad, with extensive cluster of dense, moderately modified black setae, and with distinctly convex posterior margin, posterior excision absent; aedeagus ( Figs 118-119 ) approximately 1.6 mm long, slender, distinctly asymmetric, and with small basal portion; ventral process of highly distinctive shape, asymmetric, with sharp and, in lateral view, strongly excavated ventral margin; dorsal plate indistinct, weakly sclerotized; internal sac with very long, basally dilated, and apically bifid sclerotized spine.

: protarsomeres I-IV distinctly dilated, but somewhat less so than in male; sternite VIII ( Fig. 120 ) approximately 1.2 mm long, weakly oblong, and posteriorly convexly produced; tergite IX with short antero-median portion without median suture, and with moderately long postero-lateral processes; tergite X weakly convex in cross-section, slightly more than twice as long as anteromedian portion of tergite IX ( Fig. 121 ).

Comparative notes:

The similar morphology of the aedeagus (ventral process slender and distinctly asymmetric, small basal portion, presence of a long spine in internal sac) and of the female terminalia (short antero-median portion of tergite IX), L. pium belongs to the L. fissispinosum group (see ASSING in press). It is distinguished from L. guizhouense from the Fanjing Shan, previously the sole representative of the genus recorded from Guizhou, by larger body size, the different shape and chaetotaxy of the male sternite VIII, and by the distinctive morphology of the aedeagus. For illustrations of the habitus, the male sternite VIII, and the aedeagus of L. guizhouense see CHEN et al. (2005).

Distribution and natural history:

Lathrobium pium is probably endemic to the Leigong Shan, southeastern Guizhou, where the specimens were collected at an altitude of approximately 1700 m.

Figures

Figs 114-121: Lathrobium pium sp. n.: habitus (114); forebody (115); male sternite VII (116); male sternite VIII (117); aedeagus in lateral and in ventral view (118-119); female sternite VIII (120); female tergites IX-X (121). Scale bars: 114-115: 1.0 mm; 116-121: 0.5 mm.