Labahe Natural Reserve, Sichuan Province, Southwest China

Holotype: ♂, labeled ‘CHINA: Sichuan Prov. / Tianquan County / Labahe N. R. / 30°09'N, 102°26'E / 30.vii.2006, alt. 2, 000 m / Hu & Tang leg.’. Paratypes: 4 ♂♂, 2 ♀♀, same label data as holotype; 2 ♀♀, same label data, except ‘29.v.2006’.

Measurements and ratios:BL 8.12–10.00, FL 3.78–4.11, HL 1.18–1.26, HW 1.26–1.31, PL 1.52–1.63, PW 1.30–1.41, EL 0.98–1.05, HL/HW 0.93–0.96, HW/PW 0.94–0.97, HL/PL 0.76–0.79, PL/PW 1.16–1.17, EL/PL 0.64–0.67.

Habitus as in Fig. 1A. Body brown with paler apex, legs brown to light brown, antennae brown to reddish brown.

Head subquadrate (HL/HW 0.93–0.96); punctation coarse and dense; interstices with shallow and netlike microsculpture; eyes small, approximately 1/5–1/4 of length of postocular region in dorsal view.

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

Elytra with punctation denser than that of pronotum and well defined; hind wings reduced.

Abdomen with dense punctation; interstices with very shallow, transversely striate microsculpture.

Male. Sternite VII (Fig. 2A) with short, darkish setae in U-shaped posterio-median impression; sternite VIII (Fig. 2B) with triangular, symmetrical emargination and short, darkish setae in shallow impression; sternite IX (Fig. 2C) long and nearly symmetrical; aedeagus (Fig. 2D, 2E) with very slender, ventral process.

Female. Posterior margin of tergite VIII (Fig. 2F) somewhat convex; sternite VIII (Fig. 2G) slightly longer than that of male, posterior margin broadly convex; tergite X (Fig. 2H) not acute basally and not reaching anterior margin of tergite IX (Fig. 2H).

Southwest China: Sichuan.

The specific epithet (Latin, adjective: sharp) alludes to the apical margin of the male sternite IX.

It resembles Lathrobium lijiangense Watanabe & Xiao, 1997 from Yunnan in having a similar shape of the male sternite VII. The new species can be readily distinguished from these species by the male sternite VIII with a triangular emargination at the apical margin and by the aedeagus with a much longer ventral process. In Lathrobium lijiangense, the male sternite VIII has a semi-elliptical emargination at the apical margin and the ventral process of the aedeagus is short.

Hailuogou, Sichuan Province, Southwest China

Holotype: ♂, labeled ‘CHINA: Sichuan Prov. / Luding County / Hailuogou / 29°41'N, 102°06'E / 23.vii.2006, alt. 2, 200–2, 300 m / Hu & Tang leg.’. Paratypes: 4 ♂♂, 4 ♀♀, same label data as holotype; 3 ♂♂, 4 ♀♀, same data, except ‘29°41'N, 102°07'E / 24.vii.2006, alt. 2, 800–3, 000 m’; 2 ♂♂, 4 ♀♀, same data, except ‘27.vii.2006’; 1 ♀, same data, except ‘28.vii.2006’.

Measurements and ratios:BL 7.23–8.34, FL 3.34–3.72, HL 1.04–1.11, HW 1.05–1.15, PL 1.39–1.48, PW 1.07–1.20, EL 0.93–1.02, HL/HW 0.94–0.99, HW/PW 0.96–0.99, HL/PL 0.75–0.79, PL/PW 1.23–1.30, EL/PL 0.67–0.69.

Habitus as in Fig. 1B. General appearance similar to Lathrobium acutissimum, except for somewhat smaller body size and sparser punctation on head and pronotum.

Male. Posterior margin of sternite VII (Fig. 3A) weakly concave; sternite VIII (Fig. 3B) with symmetrical, subtriangular emargination and darkish setae in large, shallow impression; sternite IX (Fig. 3C) asymmetrical; aedeagus (Fig. 3D, 3E) with slender, ventral process and short, dorsal sclerites.

Female. Posterior margin of tergite VIII (Fig. 3F) nearly truncate; sternite VIII (Fig. 3G) much longer than that of male, posterior margin strongly convex; tergite X (Fig. 3H) slender and not reaching anterior margin of tergite IX (Fig. 3H).

Southwest China: Sichuan.

The specific epithet of this new species is derived from the type locality “Hailuogou”.

The new species resembles Lathrobium zhangi Watanabe & Xiao, 1997 from Yunnan in having the posterior margin of the male sternite VII weakly concave and a similar shape of the male sternite VIII. The new species can be readily distinguished from these species by the broad ventral process of the aedeagus in lateral view. In Lathrobium zhangi, the ventral process of the aedeagus is much narrower in lateral view.

Labahe Natural Reserve, Sichuan Province, Southwest China

(1 ♂, 1 ♀). Holotype: ♂, labeled ‘CHINA: Sichuan Prov. / Tianquan County / Labahe N. R. / 30°09'N, 102°28'E / 31.vii.2006, alt. 2, 400–2, 600 m / Hu & Tang leg.’. Paratypes: 1♀, same label data as holotype.

Measurements and ratios:BL 7.02–7.54, FL 2.95–3.06, HL 0.85–0.94, HW 0.88–0.92, PL 1.22–1.25, PW 0.91–0.93, EL 0.78–0.81, HL/HW 0.97–1.02, HW/PW 0.97–0.99, HL/PL 0.70–0.75, PL/PW 1.34, EL/PL 0.64–0.65.

Habitus as in Fig. 1C. Generally similar to Lathrobium acutissimum except for lighter coloration of legs, smaller body size, and somewhat sparser punctation on head and pronotum.

Male. Posterior margin of sternite VII (Fig. 4A) concave and with short, darkish setae; sternite VIII (Fig. 4B) with semicircular, symmetrical emargination and dense, long setae in shallow impression; sternite IX (Fig. 4C) nearly symmetrical; aedeagus (Fig. 4D, 4E) with long, ventral process and thin, dorsal sclerite.

Female. Posterior margin of tergite VIII (Fig. 4F) weakly convex; sternite VIII (Fig. 4G) much longer than that of male, posterior margin strongly convex; tergite IX (Fig. 4H) not separated from tergite X (Fig. 4H).

Southwest China: Sichuan.

The specific epithet of this new species is derived from the type locality “Labahe”.

Lathrobium labahense resembles Lathrobium watanabei Schülke, 2002 in having a similar shape of the male sternite VIII, but can be readily separated by the aedeagus with a much longer ventral process.