Stenus napoensis Lv et Zhou, 2018

Lv, Wei-Xiang, Zhao, Cai-Yun & Zhou, Hong-Zhang, 2018, Ta xonomic study on the Chinese Steninae (Coleoptera, Staphylinidae), with descriptions of three new species of the Genus Stenus Latreille, Zootaxa 4429 (2), pp. 247-268 : 251-252

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

( Figs. 3 & 4 )

Type locality: China: Guangxi, Napo County.

Type material. Holotype: male, China: Guangxi: Napo County, Shuiyuanlin Nature Reserve (21°99'N, 100°79'E), 1400 m, 3.IV.1998, Hai-Sheng Zhou leg. (IZ-CAS).

Description. BL: 7.0 mm, FL: 3.4 mm, HW: 1.16 mm, PL: 1.05 mm, PW: 0.84 mm, EL: 1.36 mm, EW: 1.23 mm, SPL: 1.18 mm.

Macropterous; body dark brown. Each elytron with an oval orange spot in about posterolateral half, which is about 1/3 as long as and 3/5 as broad as the respective elytron. Antennae yellowish 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 distinctly narrower than elytra. Frons broad with two shallow longitudinal furrows, median portion slightly convex, not extending to the level of dorsal eye margins; punctures coarse and very dense, mostly well delimited, diameter of punctures as large as apical cross section of antennal segment III; interstices smooth, distinctly smaller than half the diameter of punctures. Antenna slender, when reflexed distinctly extending beyond the posterior margin of pronotum.

Pronotum distinctly longer than broad, weakly uneven, without distinct median longitudinal furrow; punctures round, mostly well delimited and smaller those on head; interstices smooth and larger than the diameter of punctures.

Elytra trapeziform, longer than wide, weakly uneven; shoulders oblique, humeral impression and long sutural impression shallow, postero-lateral impression indistinct. Punctures and interstices are similar to those of pronotum

Legs slender; tarsomeres IV deeply bilobed.

Abdomen cylindrical, with line-like paratergites on segment III–VI, anterior tergites with moderate deep basal furrows; tergite VII with distinct 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 larger than the diameter of punctures.

Male: sternite VIII ( Figs. 3 F & 4 B ) with a semicircle emargination in posterior middle; sternite IX ( Figs. 3 G & 4 C ) with a long tooth apicolaterally, posterior margin serrated; tergite X ( Figs. 3 H & 4 D ) with a small emargination in rounded posterior margin. Aedeagus ( Figs. 3 E & 4 A ) elongate, rounded apically; apical sclerotized area semicircle. Endophallus with median bands short, diverging anteriorly; expulsion clasps weakly sclerotized; copulatory tube moderately thick basally, strongly curved a little before the middle. Parameres distinctly longer than median lobe, with 22–24 setae.

Female: Unknown.

Distribution. China (Guangxi).

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

Remarks. The new species belongs to S. tenuimargo group. The species resembles S. miwai Bernhauer in most aspects, but can be distinguished by the following characteristics: the larger body size, punctures on pronotum and elytra smaller, the elytron orange spot distinctly extending beyond the margin of elytra. For this new species was found and described here, we modify here the key to Chinese species of the Stenus tenuimargo group in Lv, Zhao & Zhou (2018):

12. Elytral spot larger, about 2/3 as long as one elytron. Aedeagus as Puthz (2013b: Fig. 401)....... S. grandimaculatus Benick Elytral spot smaller, about 1/3 as long as one elytron........................................................ 12a

12a. Punctures on pronotum well delimited. Aedeagus as Figs. 5 E & 6 A................... S . napoensis Lv et Zhou, sp. nov. Punctures on pronotum distinctly confluent. Aedeagus as Lv, Zhao & Zhou (2018: Figs. 15 & 16 A)........ S. oculifer Puthz

Figures

FIGURE 3. Stenus napoensis Lv et Zhou, sp. nov. A. habitus (dorsal view); B, I. forebody; C, J. elytra; D. abdomen; E. aedeagus; F. male sternite VIII; G. male sternite IX; H. male tergite IX & X. Scale bar = 0.2 mm. (I, J for S. miwai Bernhauer, 1943).

FIGURE 4. Stenus napoensis Lv et Zhou, sp. nov. A. aedeagus; B. male sternite VIII; C. male sternite IX; D. male tergite IX & X. Scale bar = 0.2 mm.

FIGURE 5. Stenus renjiafenicus Lv et Zhou, sp. nov. A. habitus (dorsal view); B. forebody; C. elytra; D. abdomen; E. aedeagus; F. male sternite VIII; G. male sternite IX; H. male tergite IX & X. Scale bar = 0.2 mm.

FIGURE 6. Stenus renjiafenicus Lv et Zhou, sp. nov. A. aedeagus; B. male sternite VIII; C. male sternite IX; D. male tergite IX & X. Scale bar = 0.2 mm.