Lathrobium yelense Peng & Li

Peng, Zhong, Li, Li-Zhen & Zhao, Mei-Jun, 2013, Eight new apterous Lathrobium species (Coleoptera, Staphylinidae) from Sichuan, Southwest China, ZooKeys 303, pp. 1-21 : 8-9

Lathrobium yelense Peng & Li sp. n. Figs 2C, 5, 15

Type material.

(4 ♂♂, 2 ♀♀). Holotype: ♂, labelled 'CHINA: Sichuan Prov., Shimian County, Liziping. Yele, 28°54'N, 102°13'E, 15.vii.2012 alt. 2,600 m, Dai, Peng & Yin leg.' (SNUC). Paratypes: 3 ♂♂, 2 ♀♀, same label data as holotype (SNUC).

Description.

Measurements (in mm) and ratios: BL 5.95-7.39, FL 2.83-3.20, HL 0.87-0.93, HW 0.88-0.92, PL 1.15-1.18, PW 0.92-0.96, EL 0.63-0.70, AL 1.24-1.29, HL/HW 0.99-1.01, HW/PW 0.94-0.96, HL/PL 0.76-0.79, PL/PW 1.23-1.25, EL/PL 0.55-0.59.

Habitus as in Fig. 2C. Body blackish brown with paler apex, legs and antennae brown to light brown.

Head subquadrate; punctation moderately coarse and rather sparse, slightly sparser in median dorsal portion; interstices with fine microreticulation; eyes 1/4 times as long as postocular region in dorsal view.

Pronotum nearly parallel-sided; punctation similar to that of head; impunctate midline moderately broad; interstices without microsculpture.

Elytra 0.55-0.59 times as long as pronotum; punctation moderately dense, shallow, and weakly defined. Hind wings completely reduced. Protarsi with moderately pronounced sexual dimorphism.

Abdomen with fine and dense punctation, that of tergite VII slightly sparser than that of anterior tergites; interstices with shallow microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with moderately pronounced sexual dimorphism.

Male. Tergite VIII with weakly convex posterior margin; sternites III-VI unmodified; sternite VII (Fig. 5D) transverse, with weakly modified setae in shallow postero-median impression, posterior margin concave in the middle; sternite VIII (Fig. 5E) moderately transverse and impressed along the middle, on either side of this impression with numerous short and dark setae posteriorly, posterior margin shallowly concave in the middle; sternite IX (Fig. 5F) nearly symmetric; aedeagus as in Figs 5G, 5H; ventral process long and apically curved in lateral view; dorsal plate (Fig. 5I) weakly sclerotized and with long apical portion, apically acute in dorsal view; basal portion very short and thin; internal sac without distinct dark membranous structures and apically with moderately sclerotized structure.

Female. Tergite VIII (Fig. 5A) asymmetrically produced posteriorly; sternite VIII (Fig. 5B) longer than tergite VIII, distinctly produced posteriorly, posteriorly finely pubescent; tergite X (Fig. 5C) 0.4 times as long as the undivided antero-median portion of tergite IX (Fig. 5C).

Distribution and biological notes.

This species is currently known only from the type locality. Some of the type specimens were collected by sifting bamboo leaves and humus from the floor of a bamboo forestat an altitude of 2,600 m (Fig. 15).

Etymology.

The species is named after its type locality: “Yele”.

Comparative notes.

Based on the male and female sexual characters, particularly the long and large dorsal plate, and the presence of an apical internal structure of the aedeagus, Lathrobium yelense may belong belongs to the Lathrobium ensigerum group ( Assing et al. 2013). It is distinguished from the other representatives of this group by the sparser punctation on the head, the shape and chaetotaxy of the male sternite VIII, the oblong female tergite VIII, as well as by the morphology of the aedeagus.