Dianous rufidulus Shuai & Tang, 2019

Shuai, Qi & Tang, Liang, 2019, The genus Dianous in Zhejiang, East China (Coleoptera, Staphylinidae), Zootaxa 4706 (2), pp. 275-295 : 282-283

3. Dianous rufidulus Shuai & Tang , new species

( Figs. 3, 4 , 41–48)

Type material. Holotype. China: Zhejiang: ♂, glued on a card with labels as follows: “ China: Zhejiang Province, Lin’an city, East Tianmushan , 9-15. VI.2000, Li-Zhen Li leg. ” “ Holotype / Dianous rufidulus / Shuai & Tang” [red handwritten label] ( SHNU) . Paratypes. 1♂, same data as for the holotype ( SHNU) ; 1♂ 3♀♀, Longwangshan , 3.X.2003, Hu & Tang leg. ( SHNU) ; 5♂♂ 8♀♀, Lin’an city, East Tianmushan , 1050-1150m, 13. VI .2011, Peng & Zhu leg. ( SHNU, cPut).

Description. Body black with plumbeous tinge, antennae dark brown except club reddish brown, legs reddish brown except apical two fifth of femora and basal one fifth of tibiae distinctly darken, maxillary palpi reddish brown with segment 1 lighter. Pubescence silvery to brownish, distinct on head and abdomen, nearly invisible on pronotum and median portion of elytra.

BL: 4.5–5.3 mm, FL: 2.5–2.8 mm. HW: 1.00– 1.06 mm, PL: 0.77–0.85 mm, PW: 0.72–0.77 mm, EL: 1.07–1.20 mm, EW: 1.01–1.15 mm, SL: 0.88–1.02 mm.

Head 0.85–0.99 times as wide as elytra; interocular area with deep longitudinal furrows, median portion as wide as the side portions and convex posteriorly, extending to the level of inner eye margins; punctures round to oval, those at the longitudinal furrows slightly confluent, those of the remaining area well delimited, diameter of punctures much wider than medial ommatidia of eyes; interstices smooth, rarely with few traces of reticulation, narrower than half the diameter of punctures at frons and near inner margin of eyes, interstices at the median portion varied from slightly narrower to slightly wider than diameter of punctures. Antennae relative long, when reflexed, reaching the posterior margin of pronotum.

Pronotum 1.04–1.13 times as long as wide; disk uneven with transverse impression near anterior margin, two transverse impressions at about middle and transverse impression near posterior margin; punctures nearly as large as those of head, slightly confluent; interstices smooth, mostly narrower than half the diameter of punctures to narrower than diameter of punctures except few on median portion or near anterior and posterior margins, which may be a little wider than diameter of punctures.

Elytra 1.01–1.08 times as long as wide; disk relatively even; punctation strongly confluent, interstices smooth and rugae-like, long rugae at inner half portion direct from suture to midlateral portion.

Metasternum with median area impressed, sparsely punctate, diameter of punctures similar to those of head, interstices rather shiny though with shallow reticulation.

Legs slender, metatarsomere I slightly shorter than the following three segments combined, metatarsomere IV simple.

Abdomen semi-cylindrical with broad, horizontal and densely punctate paratergites, width of paratergites of segment IV as wide as median cross section of metatibia; posterior margin of tergite VII with palisade fringe; punctures variable in size, those on basal half of abdominal tergites III–VII similar to or slightly smaller than punctures of head, those on the remain portions of abdominal tergites III–VII distinctly smaller than ommatidia of eyes, those on tergite VIII about as large as ommatidia of eyes; interstices shallowly reticulated on abdominal tergites III–VII except the basal half to basal third of tergites III–VII which are nearly smooth, interstices varying from as wide as the diameter of punctures to much wider than diameter of punctures.

Male. Tergites X (Fig. 43) slightly emarginated in the middle of posterior margin; sternite VII slightly impressed at posteromedian part, posterior margin of the impression slightly emarginated; sternite VIII (Fig. 41) widely emarginated in the middle of posterior margin; sternite IX (Fig. 47) with apicolateral projections long, posterior margin indistinctly serrate. Aedeagus (Figs. 45, 46) slender, apical sclerotized area of median lobe subtriangular with lateral corners strongly prominent, dorsal surface covered with short setae; internal sac with long basal tube; parameres slender, distinctly longer than median lobe, each with 14–18 setae on inner side of apical portion.

Female. Tergites X (Fig. 44) narrower than that of male with posterior margin entire; Sternite VIII (Fig. 42) distinctly prominent at middle of posterior margin; valvifer (Fig. 48) acute apically.

Distribution. China (Zhejiang).

Etymology. The specific name “rufidulus” means red tint.

Remarks. The new species belongs to the Dianous ocellatus -complex and in general face it is similar to Dianous rugosipennis Puthz, 2000 from Fujian, Zhejiang and Anhui. The new species is now only known from Longwangshan and East Tianmushan, while D. rugosipennis can be also found from above localities and even from the same rock. The new species can be distinguished from D. rugosipennis by reddish legs (blackish in D. rugosipennis ), smaller body size in average and by more prominent lateral corners in apical sclerotized area of aedeagus.

Figures

FIGURES 1–6. Adult habitus of Dianous. 1, 2 D. coeruleotinctus 3, 4 D. coeruleovestitus 5, 6 D. rufidulus. Scale=1mm.