Lathrobium mancum ASSING & PENG, 2013

Assing, V. & S, Longwang, 2013, New species and records of Lathrobium from China and Nepal (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (2), pp. 1643-1655 : 1646-1650

Lathrobium mancum ASSING & PENG , nov.sp.

( Figs 5-8 , 12-13)

Type material: Holotype: " CHINA: Zhejiang [CH07-37], Tianmu Shan, pass 25 km NNW Linan, 620-680 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 mancum sp.n., det. V. Assing 2013" ( cSch) . Paratypes: 2, 1 [1 teneral]: same data as holotype (cSch, cAss) ; 1, 1: same data, but leg. Wrase (cAss) ; 2: same data, but leg. Pütz (cPüt, cAss) ; 1: " CHINA: Zhejiang [CH07-38], Hangzhou Pref., Tianmu Shan, S pass 41 km WNW Linan, NE valley, 350 m, 30°21'34''N, 119°19'01''E, plant refuse near creek, 17.VI.2007, M. Schülke " (cSch); 1: same data, but leg. Wrase (cSch); 3, 3: "China: Zhejiang Prov., Anji County, Longwang Mt., Qianmutian , 25.v.2009, 1300 m, Yuan, Liu, Feng & Yin leg." ( SNUC) .

Etymology: The specific epithet (Latin, adjective: mutilated, deficient) alludes to the asymmetric ventral process of the aedeagus, as well as to other asymmetries in the male and female sexual characters.

Description: Species of moderate size; body length 5.5-8.0 mm; length of forebody 3.2-3.6 mm. For a colour image of the habitus see figure 2B in PENG et al. (2012a). Coloration: body dark-brown to blackish-brown; legs and antennae dark-reddish to reddish-brown.

Head 1.05-1.10 times as broad as long, slightly dilated posteriad; punctation moderately coarse and moderately dense, sparser in postero-median dorsal portion; interstices with shallow microreticulation. Eyes weakly projecting from lateral contours of head, approximately 0.4 times as long as postocular region in dorsal view and composed of about 40-50 ommatidia. Antenna 1.8-2.0 mm long.

Pronotum approximately 1.2 times as long as broad and slightly broader than head, slightly tapering posteriad; punctation similar to that of head; impunctate midline moderately broad; interstices without microsculpture.

Elytra short, 0.51-0.54 times as long as pronotum, very weakly dilated posteriad; humeral angles moderately marked; punctation rather dense and defined; interstices without microsculpture. Hind wings completely reduced. Protarsomeres I-IV with pronounced sexual dimorphism.

Abdomen 1.05-1.10 times as broad as elytra; punctation fine and dense, somewhat less dense on tergites VII and VIII; interstices with very fine and shallow microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with distinct sexual dimorphism.

: protarsomeres I-IV strongly dilated; tergite VIII with convex posterior margin; sternite VII ( Fig. 5 ) strongly transverse, posteriorly with median impression of triangular shape, this impression with cluster of about 30 distinctly modified, short and stout black setae, posterior margin concave in the middle; sternite VIII ( Fig. 6 ) distinctly transverse, approximately 1.2 times as broad as long, with pronounced, extensive, and somewhat asymmetric median impression, this impression with numerous distinctly modified, short and stout black setae, posterior margin convex with a small concave excision in the middle; aedeagus ( Figs 7-8 ) approximately 1.1 mm long and distinctly asymmetric; ventral process stout, strongly sclerotized, and apically acute, left side with tooth-like projection in ventral view; dorsal plate lamellate, with long and weakly sclerotized apical portion and with short, indistinct basal portion; internal sac with two large, plate-like, and apically spine-shaped and prominent sclerotized structures, and with a cluster of short sclerotized spines.

: protarsomeres I-IV moderately dilated, distinctly less so than in male; posterior margin of tergite VIII obtusely produced in the middle; sternite VIII ( Fig. 12 ) oblong, approximately 1.15 times as long as broad, posteriorly convexly produced in the middle; tergite IX ( Fig. 13 ) asymmetric, antero-median portion very short and with median suture; tergite X ( Fig. 13 ) weakly asymmetric, weakly convex in cross-section, and more than five times as long as antero-median portion of tergite IX.

Comparative notes: As can be inferred from the similarly derived shapes and chaetotaxy of the male sternites VII and VIII, the similarly derived morphology of the aedeagus, as well as from the similarly asymmetric female tergites IX and X, L. mancum is undoubtedly the adelphotaxon of the geographically close L. rougemonti . It differs from this species by the shape of the posterior cluster of modified setae on the male sternite VII, the more transverse male sternite VIII with a less broad median impression, the slightly shorter aedeagus ( L. rougemonti : length of aedeagus 1.15 mm) with a stouter and shorter ventral process with a tooth-shaped projection on the left side (ventral view) and with internal structures of different shape, by the posteriorly slightly more distinctly produced female sternite VIII, and by the less strongly asymmetric female tergites IX and X.

Comment: PENG et al. (2012a) illustrated the external and sexual characters of L. mancum based on material from the Longwang Shan (as Lathrobium sp. ; figures 2B and 7). However, without a revision of the type material of the highly similar L. rougemonti , it was not possible to assess with certainty if both were conspecific or not.

Distribution and natural history: The type material was collected both in the Tianmu Shan and the Longwang Shan in Zhejiang. The specimens with labels specifying the ecological circumstances were sifted from litter and moss in a mixed forest and from plant refuse near a stream at a wide range of altitudes (350-1300 m). One of the type specimens (June) is teneral.

Figures

Figs 1-8: Lathrobium rougemonti, holotype (1-4) and L. mancum (5-8): (1, 5) male sternite VII; (2, 6) male sternite VIII; (3-4, 7-8) aedeagus in lateral and in ventral view. Scale bars: 0.5 mm.

Figs 9-18: Lathrobium barbiventre (9-10), L. rougemonti (11), L. mancum (12-13), and L. bicuspidatum (14-18): (9, 12) female sternite VIII; (10, 11, 13) female tergites IX-X; (14) forebody; (15) male sternite VII; (16) male sternite VIII; (17-18) aedeagus in lateral and in ventral view. Scale bars: 14: 1.0 mm; 9-13, 15-18: 0.5 mm.