Stenus substrictus 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 : 30-32

Stenus substrictus Tang & Puthz , sp. nov.

( Figs.1 , 6–10 )

Type material. Holotype: CHINA: Zhejiang Prov.: 3, Suichang County, Jiulongshan, alt. 500–700 m, 31.VII.2006, SHEN Shan-Jia & LI Jin-Wen leg. ( SHNU). Paratypes: CHINA: Zhejiang Prov.: 73, 9ƤƤ, same data as for the holotype (63, 8ƤƤ in SHNU, 3, Ƥ in cPut).

Description. BL: 2.8–3.2 mm; FL: 1.4–1.6 mm.

Proportional measurements of holotype: HW: 42.0, PL: 30.0, PW: 29.0, EL: 31.0, EW: 32.5, SL: 23.0.

Brachypterous, body blackish and moderately glossy, elytra a little lighter; head moderately coarsely and sparsely punctate, pronotum and elytra coarsely and densely punctate, abdomen moderately coarsely and densely (anteriorly) to finely and very sparsely (posteriorly) punctate; pubescence short, recumbent. Antennae entirely light brown. Maxillary palpi and legs yellowish. Clypeus blackish, labrum dark brown with anterior margin reddish yellow, densely pubescent.

Head 1.29 times as wide as elytra; clypeofrontal area densely punctate and pubescent; basiantennal tubercles small; interocular area with deep longitudinal furrows, median portion convex and broadly impunctate along midline, elevated distinctly below the level of inner eye margins; punctures round, well delimited, slightly larger and sparser on median area than those near inner margins of eyes, diameter of large punctures about as wide as basal cross section of 2nd antennal segment, interstices as broad as one to half puncture diameter, densely reticulated except on median convex portion. Antennae when reflexed distinctly extending beyond posterior margin of pronotum; 3rd to 8th segments much narrower than 2nd; 9th to 11th gradually broadened, forming loose club; relative length of segments from base to apex as 6.5: 5.0: 9.5: 6.5: 6.0: 4.5: 4.0: 3.0: 3.5: 3.5: 5.0. Paraglossae oval.

Pronotum 1.03 times as long as wide, 0.89 times as wide as elytra, widest at a little before middle and constricted at base; disk uneven, with moderately shallow median longitudinal furrow; punctures round and slightly confluent, almost same in size and a little larger than largest punctures on head, interstices shallowly reticulated, smaller than half diameter of punctures.

Elytra 0.95 times as long as wide, distinctly constricted at base, lateral margins gently divergent posteriad; posterior conjoint margins roundly and distinctly emarginate at middle; disk relatively even with shallow humeral impression and shallow postero-lateral impression; punctation round and slightly confluent, a little larger than those on pronotum, interstices shallowly reticulated, smaller than half diameter of punctures.

Legs elongate, hind tarsi 0.78 times as long as hind tibiae, 4th tarsomeres distinctly bilobed.

Abdomen cylindrical; without paratergites except for the trace on basal half of 3rd segment; 7th tergite with apical narrow membranous fringe; punctures round to elliptic, gradually becoming smaller posteriad, interstices faintly microsculptured on 3rd tergite and distinctly microsculptured on 4th to 10th tergites, varied from smaller to larger than half diameter of punctures.

Male. Eighth sternite ( Fig. 6 ) with triangular emargination at middle of posterior margin; 9th sternite ( Fig. 7 ) with very long apicolateral projections, posterior margin serrate and almost straight. Aedeagus ( Fig. 8 ) slender, median lobe subparallel and in apical 1/7 acutely narrowed into an obtuse sclerotized apex; expulsion hooks ( Fig. 9 ) very large, internal sac as in the figure 8; parameres extending far beyond the apex of median lobe, slightly swollen at apical portion, each with numerous long subapical setae on its inner side.

Female. Abdomen broader than that in male; 8th sternite with posterior margin slightly pointed at middle; sclerotized spermatheca as in Fig. 10 , infundibulum broad.

Remarks. This new species is similar to S. micuba Hromádka but might be distinguished by less elevated median portion of frons, shallower reticulation on pronotum and elytra, and the sexual characters.

Distribution. China (Zhejiang Province).

Etymology. The Latin adjective “ substrictus ” refers to the narrow body of the new species.

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 6 – 10. Details of Stenus substrictus sp. nov. 6 — male 8 th sternite; 7 — male 9 th sternite; 8 — aedeagus in ventral view; 9 — expulsion clasp of aedeagus; 10 — spermatheca. Scale bars 0.25 mm.