Stenus tianquanensis Tang & Puthz

Tang, Liang, Li, Li-Zhen & Puthz, Volker, 2010, Five new Stenus species of the cephalotes group (Coleoptera, Staphylinidae) from China with a key to Chinese species of the group, Zootaxa 2335, pp. 29-39 : 37-38

Stenus tianquanensis Tang & Puthz , sp. nov.

( Figs.5 , 26–30 )

Type material. Holotype: CHINA: Sichuan Prov.: 3, Tianquan County, Labahe, alt. 2000 m, 30.VII.2006, HU Jia-Yao & TANG Liang leg. ( SHNU). Paratypes: CHINA: Sichuan Prov.: 23, 2ƤƤ, same data as for the holotype (3, Ƥ in SHNU, 3, Ƥ in cPut); 2ƤƤ, same data but alt. 2400–2600 m, 31.VII.2006, HU Jia-Yao & TANG Liang leg. ( SHNU).

Description. BL: 2.5–3.0 mm; FL: 1.4–1.5 mm.

Proportional measurements of holotype: HW: 42.5, PL: 31.5, PW: 30.5, EL: 32.5, EW: 36.0, SL: 25.0; relative length of antennal segments from base to apex as 6.5: 5.0: 8.0: 5.5: 5.0: 3.5: 3.5: 2.5: 3.5: 3.5: 5.5; hind tarsi 0.74 times as long as hind tibiae.

Brachypterous, moderately glossy, head black, pronotum and abdomen dark brown, elytra paler, brown (some of the examined specimens with pronotum, elytra and abdomen distinctly darker); head, pronotum and elytra coarsely and densely punctate, abdominal punctation dense, moderately fine (anteriorly) to very fine (posteriorly) pubescence short, recumbent. Antennae reddish yellow, club infuscate. Maxillary palpi and legs reddish yellow. Clypeus blackish brown, labrum reddish brown with reddish yellow along anterior margin, densely pubescent.

Very similar to S. gonggashanus sp. nov. in most respects, but different in the following characters: median portion of frons less broad, at most as broad as each of the side portions, and less strongly elevated, slightly above the level of inner eye margins; reticulation of pronotum more indistinct, almost absent; interstices faintly microsculptured; punctation of first abdominal segment shallower and a little smaller.

Male. Eighth sternite ( Fig. 26 ) with round emargination at middle of posterior margin; 9th sternite ( Fig. 27 ) with very long apicolateral projections, posterior margin serrate and roundly emarginate. Aedeagus ( Fig. 28 ) with median lobe broadest at apicolateral corner and acutely narrowed apicad into an acuate sclerotized apex; expulsion hooks ( Fig. 29 ) large, internal sac as in the figure 28; parameres extending beyond apex of median lobe, slightly swollen at apical portion, each with about 19 subapical setae on inner side.

Female. Abdomen broader than that in male; 8th sternite with posterior margin slightly pointed at middle; sclerotized spermatheca with lunate infundibulum as in Fig. 30 .

Remarks. This new species is very similar to S. gonggashanus sp. nov., from which it may be distinguished by the exterior characters indicated above and the distinct sexual characters. This species is also similar to S. latipectus sp. nov., both distributed in the same locality, but can be distinguished by the characters listed in the key.

Distribution. China (Sichuan Province).

Etymology. The species name is derived from “Tianquan”, the type locality.

Figures

FIGURES 1 – 5. Stenus cephalotes group, habitus. 1 — S. substrictus sp. nov.; 2 — S. breviculus sp. nov.; 3 — S. gonggashanus sp. nov.; 4 — S. latipectus sp. nov.; 5 — S. tianquanensis sp. nov. Scale bars 1 mm.

FIGURES 26 – 30. Details of Stenus tianquanensis sp. nov. 26 — male 8 th sternite; 27 — male 9 th sternite; 28 — aedeagus in ventral view; 29 — expulsion clasp of aedeagus; 30 — spermatheca. Scale bars 0.25 mm.