Lathrobium erlangense 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 : 3-4

Lathrobium erlangense Peng & Li sp. n. Figs 2A, 3, 13

Type material.

(1♂, 2♀♀). Holotype: ♂, labelled 'CHINA: Sichuan Prov., Tianquan County Mt. Erlangshan, 29°52'N, 102°18'E, 13.vii.2012 alt. 2,200-2,300 m, Dai, Peng & Yin leg.' (SNUC). Paratypes: 2 ♀♀, same label data as holotype (SNUC).

Description.

Measurements (in mm) and ratios: BL 5.84-8.06, FL 2.82-3.25, HL 0.83-0.92, HW 0.87-0.94, PL 1.17-1.26, PW 0.93-1.00, EL 0.56-0.67, AL 1.30, HL/HW 0.95-0.98, HW/PW 0.94, HL/PL 0.70-0.73, PL/PW 1.26, EL/PL 0.48-0.53.

Habitus as in Fig. 2A. Body brown with paler apex, legs yellowish brown, antennae light brown.

Head subquadrate, distinctly dilated posteriorly; punctation coarse and of variable density, sparser in median dorsal area; interstices with fine microreticulation; eyes 1/4 times as long as postocular region in dorsal view.

Pronotum nearly parallel-sided; punctation somewhat sparser than that of head; impunctate midline broad; interstices without microsculpture.

Elytra approximately 0.48-0.53 times as long as pronotum; punctation fine, shallow, and moderately dense. Hind wings completely reduced. Protarsi with weakly pronounced sexual dimorphism.

Abdomen with moderately fine and dense punctation, that of tergite VII noticeably sparser than that of anterior tergites; interstices with fine microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII without sexual dimorphism, convexly produced posteriorly (Fig. 3A).

Male. Sternites III-VI unmodified; sternite VII (Fig. 3D) transverse, symmetric, and with median impression of subtriangular shape posteriorly, this impression with cluster of distinctly modified, short and stout black setae, posterior margin weakly concave in the middle; sternite VIII (Fig. 3E) transverse, symmetric, and with shallow median impression, on either side of middle with cluster of weakly modified dark setae posteriorly, posterior excision small and of semi-circular shape; aedeagus (Figs 3F, 3H) with ventral process of distinctive shape, apical portion of dorsal plate long, lamellate and moderately sclerotized, basal portion of dorsal plate very short and weakly sclerotized, internal sac with distinctly sclerotized spines.

Female. Sternite VIII (Fig. 3B) much longer than tergite VIII, distinctly produced and finely pubescent posteriorly; tergite X (Fig. 3C) 1.1 times as long as the undivided antero-median portion of tergite IX (Fig. 3C).

Distribution and biological notes.

The species is known only from one locality in the Erlang Shan, Sichuan. The specimens were collected at an altitude of 2,200-2,300 m. The holotype was sifted from rhododendron leaves and soil on the east slope of a dry ditch in a rhododendron forest (Fig. 13).

Etymology.

The species is named after the mountain where the type locality locality is situated ("Erlang Shan").

Comparative notes.

Based on the male and female sexual characters, Lathrobium erlangense undoubtedly belongs to the Lathrobium bibaculatum group (Assing, in press c). The similarly derived morphology of the aedeagus (somewhat spear-shaped ventral process, rather massive internal spines), as well as the similar modifications of the male sternites VII and VIII suggest that it is the adelphotaxon of Lathrobium bibaculatum Assing (in press c) from the Daxiang Ling, from which it is distinguished by somewhat smaller body size and by the more slender ventral process of the aedeagus.