Stenus zhangyejunianus 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 : 494-497

2. Stenus zhangyejunianus Lv et Zhou , sp. nov.

( Figs. 3 & 4 )

Type locality: China, Sichuan, Emei Shan.

Type material. Holotype: male, China: Sichuan: Emei Shan, Mountaintop (29°56'N, 103°34'E), 28.VIII. 2005, Ye-Jun Zhang leg. (IZ-CAS) . Paratypes: 1 male, 3 females, same data as for the holotype (IZ-CAS); Emei Shan, 3 males, 1 female, 700–800 m, 28.VIII.2005, Xiao-Yan Li. leg. (IZ-CAS); Qingcheng Shan, 4 males, 4 females, 21–24.VIII.2005, Cai-Yun Zhao leg. (IZ-CAS).

Description. BL: 5.2–5.9 mm, FL: 2.5–2.6 mm, HW, 1.0– 1.05 mm, PL: 0.83–0.87 mm, PW: 0.72–0.75 mm, EL: 0.95–0.99 mm, EW: 0.93–0.98 mm, SPL: 0.72–0.74 mm.

Macropterous; body black with a faint brownish hue. Each elytron with an oval orange spot in about posterolateral half, which is about 1/2 as long as and 1/2 as broad as the respective elytron. Antennae red brown, club slightly infuscate; maxillary palpi yellowish, segment III infuscate; legs red brown, but knees darker; clypeus black, labrum dark brown with sparse pubescence; paraglossae oval.

Head slightly broader than elytra. Frons broad with a pair of shallow and broad longitudinal furrows, median portion slightly elevated, nearly extending to the level of dorsal eye margins; punctures coarse and very dense, partly confluent, diameter of punctures as large as largest cross section of antennal segment II; interstices smooth and distinctly smaller than half the diameter of punctures. Antenna slender, when reflexed distinctly extending beyond the posterior margin of pronotum.

Pronotum longer than broad, slightly uneven, with a shallow median furrow, a moderately deep impression in the middle and several transverse impressions in posterior half; punctures distinctly confluent, about as large as those on frons.

Elytra subtrapezoid, longer than wide; weakly uneven, shoulders oblique, postero-lateral impression indistinct, longitudinal humeral impression distinct and long sutural impression shallow; punctation more or less confluent, slightly smaller than those on pronotum; interstices smooth, more or less ridge-like, smaller than half the diameter of punctures.

Legs slender; tarsomeres IV deeply bilobed, tarsomere I slightly shorter than the three following segments combined.

Abdomen cylindrical, with very narrower and line-like paratergites on tergites and moderately deep basal furrows on anterior segments, tergite VII with a distinct apical membranous fringe; punctures round, punctures of abdominal tergite III as large as those on elytra in average, becoming smaller and sparser posteriorly; punctures on tergite VII slightly smaller than eye facets near dorsal eye margin, interstices slightly larger than punctures.

Male: sternite VIII ( Figs. 3F & 4B ) posteromedially with a large, almost V-shaped emargination; sternite IX ( Figs. 3G & 4C ) with long acute apicolaterally; tergite X ( Figs. 3H & 4D ) entire or very weakly emarginate posteriorly. Aedeagus ( Figs. 3E & 4A ), median lobe triangularly narrowed into a weakly scleritized, button shaped apex and with a median longitudinal keel, expulsion clasps large, inner sac slender; parameres slightly longer than median lobe, moderately swollen at apex, each with 14–16 setae on apico-internal margins.

Female: sternite VIII ( Figs. 3I & 4E ) pointed posteromedially; sternite X ( Figs. 3J & 4F ) round but with a small emargination at posterior margin. Valvifer ( Figs. 3K & 4G ). Spermatheca ( Figs. 3L & 4H ) weekly sclerotized and spermathecal duct with 3 bends.

Distribution. China (Sichuan).

Etymology. The specific name is dedicated to Ms. Ye-Jun Zhang, who collected some specimens of the new species.

Remarks. Stenus zhangyejunianus Lv et Zhou , sp. nov., belongs to S. tenuimargo group. In most respects it is similar to S. notaculipennis emeiensis Zheng , but differs in the body size larger, punctures distinctly confluent on pronotum, aedeagus and spermatheca distinctly different in shape.

Figures

FIGURE 3. Stenus zhangyejunianus Lv et Zhou, sp. nov. A. habitus (dorsal view); B. forebody; C. elytra; D. abdomen; E. aedeagus; F. male sternite IX; G. male sternite VIII; H. male tergite X; I. female sternite VIII; J. female tergite X; K. valvifer; L. spermathecar; Scale bar = 0.2 mm.

FIGURE 4. Stenus zhangyejunianus Lv et Zhou, sp. nov. A. aedeagus; B. male sternite VIII; C. male sternite IX; D. male tergite X; E. female sterniteVIII; F. female tergite X; G. valvifer; H. spermathecar; Scale bar = 0.2 mm.