Stenus nabanhensis Lv et Zhou, 2018

Lv, Wei-Xiang, Zhao, Cai-Yun & Zhou, Hong-Zhang, 2018, Taxonomy of Stenus tenuimargo group (Coleoptera, Staphylinidae, Steninae) with descriptions of two new species from China, Zootaxa 4394 (4), pp. 490-516 : 492

1. Stenus nabanhensis Lv et Zhou , sp. nov.

( Figs. 1 & 2 )

Type locality: China, Yunnan, Jinghong County, Nabanhe Nature Reserve.

Type material. Holotype: male, China: Yunnan: Jinghong County, Nabanhe Nature Reserve, Naban Tea Factory (21°99'N, 100°79'E), 709 m, 10.XI.2008, Ling-Zeng Meng leg. (IZ-CAS) . Paratypes. 2 males, same data as for the holotype. (IZ-CAS).

Description. BL: 5.0 mm, FL: 2.3 mm, HW: 0.99 mm, PL: 0.84 mm, PW: 0.68 mm, EL: 1.04 mm, EW: 1.01 mm, SPL: 0.80 mm.

Macropterous; body black with shining hue. Antennae red brown, club slightly infuscate; maxillary palpi yellowish brown; legs red brown, but knees darker; clypeus black, labrum dark brown with moderate dense pubescence; paraglossae oval.

Head slightly narrower than elytra. Frons broad with two broad and shallow longitudinal furrows, median portion slightly convex, not extending to the level of dorsal eye margins; punctures coarse and very dense, on median area slightly larger and sparser than near inner margins of eyes, diameter of punctures as large as apical cross section of antennal segment II; interstices smooth and distinctly smaller than half the diameter of punctures. Antenna slender, when reflexed just extending to the posterior margin of pronotum.

Pronotum distinctly longer than broad, broadest about in the middle; weakly uneven, without distinct median furrow; punctures on pronotum distinctly reticulated and about as coarse as those on head; interstices smooth and narrower than half the diameter of punctures.

Elytra subquadrate, longer than wide, weakly uneven; shoulders oblique rectangular, humeral impression and a long sutural impression shallow, postero-lateral impression indistinct. Punctures coarse and dense, more or less confluent, slightly smaller than those on pronotum; interstices not smooth, more or less rugae-like.

Legs slender; tarsomeres IV deeply bilobed, tarsomere I as long as the three following segments together.

Abdomen cylindrical, with line-like but complete paratergites, anterior tergites with deep basal furrows; tergite VII with a distinct but narrow membranous fringe apically; punctures coarse and moderately dense anteriorly, becoming fine and sparse posteriad; punctures on tergite VII slightly smaller than eye facets near dorsal eye margin, interstices slightly larger than punctures.

Male: sternite VIII ( Figs. 1F & 2C ) with a large triangular emargination in posterior middle; sternite IX ( Figs. 1G & 2B ) with an acute tooth apicolaterally; tergite X ( Figs. 1H & 2D ) with a small emargination in rounded posterior margin. Aedeagal median lobe ( Figs. 1E & 2A ) slender; apical sclerotized area triangular and with a median longitudinal keel; expulsion clasps large and weekly sclerotized; basal tube broad, basal room spherical, almost membranous; parameres distinctly longer than median lobe, distinctly swollen at apex, each with 17–19 moderately long setae apically.

Female: Unknown.

Distribution. China (Yunnan).

Etymology. The specific epithet is derived from the name of the type locality.

Remarks. Stenus nabanhensis Lv et Zhou , sp. nov., belongs to S. tenuimargo group. The species can be easily distinguished from other related species by the elytra without an oval orange spot, and it differs from S. semilineatus by shorter elytra and by the sexual characters of male.

Figures

FIGURE 1. Stenus nabanhensis Lv et Zhou, sp. nov. A. habitus (dorsal view); B. forebody; C. elytra; D. abdomen; E. aedeagus; F. male sterniteVIII; G. male sternite IX; H. male tergite X; Scale bar = 0.2 mm.

FIGURE2. Stenus nabanhensis Lv et Zhou, sp. nov. A. aedeagus; B. male sterniteIX; C. male sternite VIII; D. male tergite X; Scale bar = 0.2 mm.