Stenus iustus Puthz, 1976

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 : 262-264

6. Stenus iustus Puthz, 1976

( Figs. 11 & 12 )

Puthz, 1976: 8, 26 (subgenus Parastenus ; Type locality: India: West Bengalen: Darjeeling District, Kurseong. Also cited from Nepal); Puthz, 1978: 131 (India); Puthz, 1980: 192 (characters; India); Herman, 2001: 2236 (catalog); Smetana, 2004: 543 (Palaearctic catalog); Puthz, 2013b:1386; Schülke & Smetana, 2015: 824 (Palaearctic catalog).

Material examined: 1 male, China: Yunnan: Tengchong County, Tongbiguan , Sanhe village , 24.VI.2016, Xiao- Yan Li leg. (IZ-CAS) ; 4 females, Tengchong County, Tongbiguan , 26.VI.2016, Xiao-Yan Li leg. (IZ-CAS) ; 2 females, Tengchong County, Yunfengshan , 29.VI.2016, Xiao-Yan Li leg. (IZ-CAS).

Redescription: BL: 2.8–3.5 mm, FL: 1.8–2.0 mm, HW: 0.76–0.80 mm, PL: 0.70–0.75 mm, PW: 0.54–0.57 mm, EL: 0.76–0.80 mm, EW: 0.76–0.80 mm, SL: 0.62–0.67 mm.

Macropterous; body black with faint luster. Antennae dark brown, maxillary palpi yellowish brown, legs red brown with darker knees; clypeus black, labrum dark brown with sparse pubescent; paraglossae oval.

Head as wide as elytra. Interocular area with a pair of shallow longitudinal furrows, median portion very slightly convex, not reaching the level of inner eye margins; punctures round, mostly well delimited, the diameter of large punctures as wide as apical cross section of antennal segment II, interstices smooth and smaller than half of puncture diameter. Antennae slender, nearly reaching posterior margin of pronotum when reflexed backwards.

Pronotum markedly longer than wide; disk uneven, without distinct median longitudinal furrow; punctures on pronotum mostly fine-delimited, similar to those on head; interstices smooth and smaller than half of puncture diameter.

Elytra as long as wide; sides inflated, widest just in the middle. Elytra convex, without distinct humeral depression and postero-lateral impression; long sutural impression shallow. Punctures and interstices on elytra same as those on pronotum.

Legs with tarsomere IV deeply bilobed.

Abdomen cylindrical, tergites III–VII with broad and complete paratergites; with shallow basal furrows on anterior segments, tergite VII with apical membranous fringe; punctures round, dense, moderate to small in size and becoming slightly smaller posteriad; punctures on tergite VII distinctly larger than one dorsal eye facet, interstices three times as large as puncture diameter.

Male: sternite VIII ( Figs. 11 F & 12 B ) posteromedially with small triangular emargination; sternite IX ( Figs. 11 G & 12 C ) with long projections and irregularly strong serrate apicolaterally; tergite IX & X ( Figs. 11 H & 12 D ) entire posteriorly. Aedeagus ( Figs. 11 E & 12 A ) bulbous basally, with semi-circular apical sclerotized area. Endophallus with median bands moderately long, broad; expulsion clasps each other, each clasp pointed anteriorly; copulatory tube long, thick, baculiform, narrowed apically. Parameres distinctly longer than median lobe, each bulbous at apical parts, with 12–14 setae on apico-mesial margins.

Female: sternite VIII ( Figs. 11 I & 12 E ) weakly pointed posteromedially; Gonocoxite ( Figs. 11 J & 12 F ) with strong serrate apicolaterally; tergite IX & X ( Figs. 11 H & 12 G ) rounded apically; sclerotized spermatheca ( Figs. 11 L & 12 H ) with a large and round infundibulum.

Distribution. China (Yunnan), India, Nepal.

Remarks. This species belongs to Stenus virgula group and is the new record to China.

Figures

FIGURE 11. Stenus iustus Puthz, 1976. 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; I. female sternite VIII; J. female tergite IX & X; K. gonocoxite; L. spermathecal. Scale bar = 0.2 mm.

FIGURE 12. Stenus iustus Puthz, 1976. A. aedeagus; B. male sternite VIII; C. male sternite IX; D. male tergite IX & X; E. female sternite VIII; F. female tergite IX & X; G. gonocoxite; H. spermatheca; Scale bar = 0.2 mm.