Lathrobium agglutinatum Assing & Peng

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 : 18-20

Lathrobium agglutinatum Assing & Peng sp. n. Figs 10B, 12, 17

Type material.

(3 ♂♂). Holotype: ♂, labelled 'CHINA: Sichuan Prov., Dujiangyan City, Mt. Qingchengshan, 30°57'N, 103°28'E, 30.vii.2012 alt. 1,700 m, Dai, Peng & Yin leg.' (SNUC). Paratypes: 1 ♂, same label data as holotype (SNUC); 1 ♂, 'China (Sichuan) 1999, Qingcheng-shan, (Umg. Heavenly Old Village) 1000-1300 m, 18./20.VI. Heinz leg.' (cAss).

Description.

Measurements (in mm) and ratios: BL 7.78-9.51, FL 4.00-4.28, HL 1.25-1.28, HW 1.38-1.40, PL 1.63-1.68, PW 1.40-1.43, EL 0.81-0.83, AL 1.65-1.70, HL/HW 0.91, HW/PW 0.98-0.99, HL/PL 0.77, PL/PW 1.16-1.17, EL/PL 0.49-0.50.

Habitus as in Fig. 5A. Body dark brown with paler apex, legs and antennae brown to light brown.

Head subquadrate; punctation dense and coarse; interstices with fine microreticulation; eyes 0.3 times as long as postocular region in dorsal.

Pronotum with weakly convex lateral margins in dorsal view; punctation somewhat sparser than that of head; impunctate midline narrow; interstices without microsculpture.

Elytra 0.49-0.50 times as long as pronotum; punctation shallow and much denser than that of pronotum; interstices without distinct microsculpture. Hind wings reduced.

Abdomen much broader than elytra, with fine and dense punctation, that of tergite VII sparser than that of anterior tergites; interstices with shallow microsculpture; posterior margin of tergite VII without palisade.

Male. Sternites III-VI unmodified; sternite VII (Fig. 12A) strongly transverse and with short dark seta in triangular postero-median impression, posterior margin nearly truncate; sternite VIII (Fig. 12B) transverse and weakly impressed in postero-median portion, posterior excision pronounced, deep and asymmetric, anterior margin of this excavation with short dark setae; sternite IX (Fig. 12D) asymmetric; aedeagus as in Figs 12C, 12E; ventral process and dorsal plate fused; basal portion of aedeagus small; internal sac with usual ring-shaped structure.

Female. Unknown.

Distribution and biological notes.

The species is known only from one locality in the Qingcheng Shan, Sichuan. Two specimens were collected by sifting leaf litter and humus from the floor of a hardwood forest with Cherokee rose and Rubus at an altitude of 1,700 m (Fig. 17).

Etymology.

The specific epithet is the past participle of the Latin verb agglutinare (to glue together) and alludes to the fused ventral process and dorsal plate of the aedeagus.

Comparative notes.

Lathrobium agglutinatum is undoubtedly closely related to Lathrobium conexum and belongs to the Lathrobium iunctum group (Assing et al., 2013). This conclusion is supported by the similarly derived structure of the aedeagus (ventral process and dorsal plate fused, asymmetric, and slender; basal portion small; internal sac with small and weakly sclerotized basal sclerite); the similarly derived shape and chaetotaxy of the male sternite VIII (posterior excision asymmetric, the anterior margin of this excavation with short dark setae), and by the extremely similar external characters. Both species are best distinguished by the completely different shape and chaetotaxy of the male sternite VII and by the differently shaped apex of the aedeagus. For illustrations of the species of the Lathrobium iunctum group from the Emei Shan see Assing et al. (2013).