Lathrobium

Peng, Zhong, Li, Li-Zhen & Zhao, Mei-Jun, 2014, Seventeen new species and additional records of Lathrobium (Coleoptera, Staphylinidae) from mainland China, Zootaxa 3780 (1), pp. 1-35 : 26-27

Lathrobium lui Peng and Li, new species

( Figs 17 B, 19)

Type material. (5 ♂♂, 12 ♀♀). HOLOTYPE: ♂, labelled ‘ CHINA: Guizhou Prov., Suiyang County, Kuankuoshui N. R., 28°14'N, 107°10'E, 7.vi.2010 alt. 1,530–1,550 m, Lu, Yin & Zhai leg.’ ( SNUC). PARATYPES: 2 ♂♂, 7 ♀♀ [1♂, 1♀ teneral], same label data as holotype, 1 ♂, 1 ♀ [1♀ teneral], same data, but ‘ 18.viii.2010 alt. 1,550 m, Yin & Feng leg.’; 1 ♂, 3 ♀♀, same data, but ‘ 28°13'N, 107°09'E, 9.vi.2010 alt. 1,550 m’; 1 ♀, same data, but ‘ 15.viii.2010 alt. 1,550 m, Z. W. Yin leg.’ ( SNUC).

Description. Measurements (in mm) and ratios: BL 5.78–6.62, FL 3.00–3.39, HL 0.83–0.92, HW 0.87–0.94, AnL 1.63–1.81, PL 1.07–1.15, PW 0.89–0.96, EL 0.64–0.72, AL 0.91–0.93, HL/HW 0.95–0.98, HW/PW 0.96– 0.98, HL/PL 0.78–0.80, PL/PW 1.20–1.21, EL/PL 0.60–0.63.

Habitus as in Fig. 17 B. Body brown with slightly paler apex, legs light brown to yellowish brown, antennae light brown.

Head approximately as long as broad; punctation coarse and moderately dense, sparser in median dorsal portion; interstices with shallow microreticulation. Eyes 0.25–0.30 times as long as postocular region in dorsal view and composed of approximately 50 ommatidia.

Pronotum nearly parallel-sided; punctation somewhat sparser than that of head; impunctate midline moderately narrow; interstices without microreticulation.

Elytra moderately short; punctation dense and very shallow. Hind wings completely reduced. Protarsi without sexual dimorphism.

Abdomen with fine and dense punctation, that of tergite VII somewhat sparser than that of anterior tergites; interstices with very shallow microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII ( Fig. 19 A) without sexual dimorphism, posterior margin very weakly convex.

Male. Sternites III–IV unmodified; sternite VII ( Fig. 19 D) moderately transverse, with very shallow median impression posteriorly, this impression with sparse unmodified setae, posterior margin nearly truncate; sternite VIII ( Fig. 19 E) transverse, with extensive and very shallow median impression, this impression with very sparse unmodified setae, posterior margin broadly and asymmetrically concave; aedeagus as in Figs 19 F, G, short, strongly modified and asymmetric, with stout and strongly asymmetric ventral process; dorsal plate asymmetric and broad; internal sac without appreciable structures, aside from a membranous ring-shaped structure.

Female. Posterior margin of sternite VIII ( Fig. 19 B) strongly convex; tergite IX ( Fig. 19 C) with very short median portion, without median suture, and with long postero-lateral processes; tergite X 5.5 times as long as antero-median portion of tergite IX ( Fig. 19 C).

Comparative notes. As can be inferred from the similarly derived morphology of the aedeagus, from the morphology the female tergite IX (undivided, anteriorly much shorter than tergite X), L. lui may belong to the L. fissispinosum group ( Assing, 2013a), which previously included eleven species from the Qinling Shan, the Daba Shan and adjacent mountain ranges. The new species is distinguished from the other representatives of this group by the chaetotaxy of the male sternite VIII (very sparse unmodified setae on the shallow median impression posteriorly) and the strongly modified and asymmetric aedeagus. For illustrations of the species of the L. fissispinosum group see Assing (2013a) and Peng et al. (2013b). The new species is distinguished from the syntopic L. zhaigei by somewhat smaller body size, by the more slender pronotum, the chaetotaxy of the male sternites VIII (less furnished with modified setae), and particularly by the distinctive morphology of the stout aedeagus.

Distribution and biological notes. The type locality is situated in the Kuankuoshui Natural Reserve to the north of Suiyang, northern Guizhou. The specimens were sifted from leaf litter in mixed deciduous forests at altitudes of 1,530–1,550 m, partly together with L. zhaigei sp. n.

Etymology. The species is named after Min Lu, who collected some of the type specimens.

Figures

FIGURE 17. Habitus of Lathrobium spp., A — L. fanjingense; B — L. lui; C — L. zhaigei. Scale bars: 1.0 mm.

FIGURE 19. Lathrobium lui. A — female tergite VIII; B — female sternite VIII; C — female tergites IX – X. D — male sternite VII; E — male sternite VIII; F — aedeagus in ventral view; G — aedeagus in lateral view. Scale bars: 0.5 mm.