Lasinus orientalis Yin and Bekchiev, new species

Lasinus orientalis Yin and Bekchiev, new species

Figs 1–2

Type material (3 ♂♂, 3 ♀♀). Holotype: CHINA: ♂, labeled ‘ China: S. Zhejiang, Lishui City, Fengyang Shan N.R., forest nr. Lv’ye Hotel, 27°53′59″N, 119°09′41″E, coniferous & bamboo litter, sifted, 1,700 m, 8.x. 2013, Z. Peng, Y.-M. Yu, Z.-W. Yin leg. / HOLOTYPE [red] ♂, Lasinus orientalis sp. n., des. Yin & Bekchiev, 2013, SNUC’. Paratypes: CHINA: 1 ♀, same label data as holotype; 1 ♀, same locality, except ‘forest nr. Datianping, 27°54′33″-55′18″ N, 119°10′20″-17″E, mixed litter, moss, sifted, 1,170–1,300 m, 6.x.2013 ’; 1 ♂, labeled ‘ CHINA: Zhejiang, An’ji County, Longwang Shan, Tong-Hang-Gang, 30°24′53″N, 119°26′52″E, ca. 1400 m, bamboo, leaf litter, sifted, 10.vi.2012, Hu & Yin leg.’; 1 ♂, 1 ♀, labeled ‘ China: NE Jiangxi, Shang’rao City, Sanqing Shan National Park, path in mixed forest, 28°54′21″N, 118°03′36″E, mixed litter, sifted, 1500–1600 m, 3.v.2006, J.-Y. Hu & L. Tang leg.’. All paratypes bear the following label: ‘ PARATYPE [yellow] ♂ [or ♀], Lasinus orientalis sp. n., des. Yin & Bekchiev, 2013, SNUC’.

Diagnosis. Large-sized, length 3.55–3.94 mm. Antennal clubs simple, lacking modification in male. Pronotal lateral margins slightly angulate anterolaterally. Pro- and mesotrochanters and femora each with a short spine at ventral margin. Aedeagus with median lobe slightly asymmetric.

Description. Male (Fig. 1 A). Length 3.55–3.93 mm. Head longer than wide, HL 0.90–0.98 mm, HW 0.71–0.74 mm; eyes each composed of about 45 facets. Antennal clubs (Fig. 2 A) formed by apical three enlarged antennomeres, simple, lacking modification. Pronotum (Fig. 2 B) about as long as wide, PL 0.67–0.84 mm, PW 0.67–0.81 mm, with anterolateral margins slightly angulate. Elytra wider than long, EL 0.99–1.03 mm, EW 1.50–1.52 mm, posterior margin densely setose. Triangular metaventral processes (Fig. 2 C) short. Protrochanters, profemora (Fig. 2 D) and mesotrochanters (Fig. 2 E) each with one small ventral spine, mesofemora (Fig. 2 E) each with tiny ventral spine at basal third, metatrochanters and metafemora (Fig. 2 F) simple. Abdomen large, AL 0.99–1.08 mm, AW 1.49–1.60 mm, tergite IV with short dorsal carinae. Sternite IX as in Fig. 2 G. Aedeagal length 0.69 mm; median lobe (Figs 2 H–J) broad, slightly asymmetric, obliquely truncate at apex; endophallus composed of two sclerites, dorsal sclerite larger than ventral sclerite, broadly bifurcate apically, ventral sclerite much more slender, curved leftwards.

Female (Fig. 1 B). Similar to male in general; eyes each composed of about 30 facets; metaventral processes absent; mesotrochanters each with two small ventral spines. BL 3.69–3.94 mm, HL 0.88–0.96 mm, HW 0.70–0.76 mm, PL 0.79–0.88 mm, PW 0.79–0.85 mm, EL 0.91–0.94 mm, EW 1.50–1.63 mm, AL 1.11–1.16 mm, AW 1.63–1.73 mm.

Intraspecific variation. The population of Feyang Shan (Type locality) has the right branch of the dorsal sclerite of the aedeagal endophallus being longer than the left branch, while the right branch is shorter, but still slightly longer than the left branch in the population of Longwang Shan (Zhejiang), and is of the same length as the left branch in the population of Sanqing Shan (Jiangxi).

Comparative notes. The new species shares the unmodified male antennal clubs with L. sinicus Bekchiev, Hlaváč & Nomura, L. inexpectatus Bekchiev, Hlaváč & Nomura, and L. yamamotoi Bekchiev, Hlaváč & Nomura. From all these species L. sinicus can be best separated by the male aedeagal structure and the distribution. The only Chinese congener, L. sinicus, has the aedeagal endophallus with a large, deeply bifid sclerite, and a weakly-sclerotized lamella with dentation at left margin. Lasinus orientalis has the endophallus lacking such a lamella, but has a broad, apically-split dorsal sclerite, and a slender, curved ventral sclerite.

Distribution. East China: Zhejiang, Jiangxi.

Etymology. The species epithet ‘ orientalis ’ means ‘Eastern, easterly’, indicating that the new species was discovered in eastern China.