Dianous pengi Wang, Tang & Luo, 2019

Wang, Wei, Tang, Liang & Luo, Yong-Ting, 2019, Notes on the genus Dianous LEACH, 1819 with description of a new species from China (Coleoptera, Staphylinidae), Zootaxa 4686 (2), pp. 282-288 : 284-287

Dianous pengi Wang, Tang & Luo sp. n.

( Figs. 7, 8 , 27–32)

Type material. Holotype. China: Guangxi: ♂, glued on a card with labels as follows: “ China: Guangxi Prov. , Jinxiu County, 16 km, alt. 900m, 29.VII.2011, Peng Zhong leg.” “ Holotype / Dianous pengi / Wang, Tang & Luo” [red handwritten label] ( SHNU) . Paratypes. 3♂♂ 1♀, same data as for the holotype ; 2♂♂ 2♀♀, same data as for the holotype except 31.VII.2011, Zhu Jian-Qing leg. ( SHNU) ; 2♂♂ 1♀♀, Guangxi Prov. , Jinxiu County, 16 km, alt. 850–950 m, 24.VII.2011, Peng Zhong leg. ( SHNU, cPut) .

Description. Head, pronotum, abdomen and appendages black with strong blue metallic tint, elytra dark blue, each with a large violet to coppery mark on posterior half reaching the lateral margin of the elytron, portions along anterior and inner margins of the marks distinctly lighter than remain portions. Pubescence silvery to brownish, nearly invisible on pronotum.

BL: 5.5–6.2 mm, FL: 3.0– 3.2 mm. HW: 1.11–1.17 mm, PL: 0.79–0.83 mm, PW: 0.83–0.88 mm, EL: 1.46–1.62 mm, EW: 1.35–1.49 mm, SL: 1.27–1.35 mm.

Head 0.76–0.84 times as wide as elytra; interocular area with deep longitudinal furrows, median portion slightly narrower than the side portions and convex posteriorly, extending a little beyond the level of inner eye margins; punctures round and well delimited except those at the furrows between median and side portions more or less longitudinal confluent; diameter of punctures as wide as medial ommatidia of eyes; interstices reticulated, distinctly narrower than half the diameter of punctures. Antennae relative long, when reflexed, reaching the humeral portion of elytra.

Pronotum 0.93–0.97 times as long as wide; disk uneven with two large basal impressions and two transverse lateromedian impressions, each basal impression with a large outer tubercle; punctures slightly larger than those of head, mostly confluent; interstices reticulated, narrower than half the diameter of punctures, more or less rotated around the median portion.

Elytra 1.05–1.09 times as long as wide; disk slightly uneven with shallow humeral impressions and shallow sutural impressions; punctures similar to those of head though slightly larger in average; interstices indistinctly microsculptured, narrower than half the diameter of punctures.

Metasternum with median area impressed, sparsely punctate and densely reticulated, diameters of punctures similar to or smaller than those of head.

Legs slender, metatarsomere 1 slightly longer than the following three segments combined, metatarsomere 4 simple.

Abdomen semi-cylindrical with broad, horizontal and densely punctate paratergites, width of paratergites of segment IV slightly wider than median cross section of metatibia; posterior margin of tergite VII with palisade fringe; abdominal tergites III–VII with punctation oval, interstices microsculptured and mostly smaller than half the diameter of punctures; tergite VIII with punctation distinctly larger than those of former tergites, interstices shallowly reticulated, smaller than diameter of punctures.

Male. Sternite VII slightly emarginated; sternite VIII ( Fig. 27 ) broadly emarginated in the middle of posterior margin; sternite IX ( Fig. 28 ) with apicolateral projections indistinct, posterior margin emarginated. Aedeagus ( Fig. 29, 30 ) robust, median lobe gradually tapering apicad and broadly blunted at apex, anterior margin of apical sclerotized portion with few short setae, parameres slender, longer than median lobe, each with 8–11 setae on inner side of apical portion.

Female. Sternite VIII ( Fig. 31 ) with two acute projection in the middle; valvifer ( Fig. 32 ) rounded apically.

Etymology. This species is named in honor of Dr. Peng Zhong, the collector of the species.

Distribution. China (Guangxi).

Remarks. The new species belongs to Dianous calceatus complex. It can be easily distinguished from other species by the smaller size, each elytron with only one metallic mark on posterior half, and pronotum with dense punctation.

Figures

FIGURES 1–8. Habitus. 1, 2 Dianous calvicollis 3, 4 D. huanghaoi 5, 6 D. luteostigmaticus 7, 8 D. pengi. Scale bars: 1 mm.

FIGURES 27–32. Sexual characters of Dianous pengi. 27 Male sternite VIII 28 male sternite IX 29, 30 aedeagus 31 female sternite VIII 32 valvifer. Scale bars: 0.25 mm.