Dianous pseudaerator Tang & Hu, 2018

Tang, Liang & Hu, Cheng-Zhi, 2018, Notes on the Dianous aereus complex with description of a new species (Coleoptera, Staphylinidae), Zootaxa 4514 (4), pp. 573-582 : 576-581

Dianous pseudaerator Tang & Hu sp. n.

( Figs. 5 , 11, 17, 19, 21, 22, 27, 34, 35)

Type material. Holotype. China: Fujian: ♂, glued on a card with labels as follows: “ China: Fujian Prov., Wuyishan , alt. 1100 m, 10.VII.2009, Xiao-Bing Song leg.” “ Holotype / Dianous pseudaerator / Tang & Hu” [red handwritten label] (SHNU). Paratypes. 2♂♂ 2♀♀, same data as for the holotype ( SHNU, cPut) ; 3♂♂ 2♀♀, Wuyishan , Guadun Vill., 27°44′N, 117°38′E, alt. 1100–1500 m, 27–29.V.2012, Peng & Dai leg. ( SHNU) .

Description. Body black with faint blue metalic tinge except elytra with bronze to olive green tinge, antennae dark brown with faint blue metalic tinge except club light brown, legs blackish with faint blue metalic tinge except tarsomeres brownish, maxillary palpi brownish with segment III slightly darker. Pubescence silvery, distinct on head and abdomen, nearly invisible on pronotum and median portion of elytra.

BL: 4.1–4.6 mm, FL: 2.4–2.6 mm.

HW: 0.86–0.94 mm, PL: 0.71–0.77 mm, PW: 0.70–0.77 mm, EL: 1.03–1.16 mm, EW: 1.03–1.17 mm, SL: 0.92–1.00 mm.

Head 0.78–0.84 times as wide as elytra; interocular area with deep longitudinal furrows, median portion as wide as the side portions and convex posteriorly, extending a little beyond the level of inner eye margins; punctures round to oval, those at the longitudinal furrows more or less confluent, those of the remaining area well delimited, diameter of punctures much wider than medial ommatidia of eyes; interstices reticulated, mostly narrower than half the diameter of punctures, except those along the midline which could be as wide as diameter of punctures. Antennae relative long, when reflexed, reaching the posterior margin of pronotum.

Pronotum 0.99–1.03 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 distinctly larger than those of head, mostly confluent; interstices reticulated, rugae-like and somewhat vorticose, mostly narrower than half the diameter of punctures except few on median portion or near anterior and posterior margins, which may be as wide as punctures.

FIGURES 23–30. Sexual characters. 23– 28 male sternite IX 29, 30 aedeagus 23, 29 Dianous vietnamensis 24, 30 D. rougemontianus 25 D. ruginosus 26 D. aerator 27 D. pseudaerator 28 D. brevicornis . Scale bars: 0.25 mm.

Elytra 0.97–1.04 times as long as wide; disk relatively even; punctation strongly confluent, interstices reticulated and rugae-like, long rugae at inner half portion direct from suture to midlateral portion.

Metasternum with median area impressed, sparsely punctate and densely reticulated, diameter of punctures similar to those of head.

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 on abdominal tergites III–VII minute, similar to or slightly smaller than ommatidia of eyes, those on tergite VIII distinctly larger than ommatidia of eyes; interstices transversely reticulated, varying from a little narrower than half the diameter of punctures to a little broader than diameter of punctures.

Male. Sternite VII (Fig. 11, 17) impressed at posteromedian part delimited by edged ridge on each side, posterior margin of the impression emarginated with distinct projection on each side; sternite VIII ( Fig. 19 ) with deep emargination in the middle of posterior margin which is 0.23 times as long as the sternite; sternite IX (Fig. 27) with apicolateral projections long, posterior margin serrate. Aedeagus ( Figs. 34, 35 ) slender, median lobe gradually tapering apicad and braodly rounded at apex, apical sclerotized area slightly twisted on right side with long setae ventrally; internal sac with long basal tube; parameres slender with left paramere slightly bent outwards and right paramere twisted on ventral side, distinctly longer than median lobe, each with 6–8 setae on inner side of apical portion.

Female. Sternite VIII ( Fig. 21 ) distinctly prominent at middle of posterior margin; valvifer ( Fig. 22 ) acute apically.

Distribution. China (Fujian).

Remarks. The new species is very similar to Dianous ruginosus Zheng, 1993 from Sichuan, Dianous aerator Puthz, 2016 widely distributed in China, D. aereus Champion, 1919 from Yunnan and adjacent countries and D. rougemontianus Puthz, 2000 from Sichuan and Hubei, but may be distinguished from them by more confluent punctation of head and pronotum, pronotum without bronze tint and the different male sexual characters, from D. rougemontianus also differs by smaller size, and from D. aereus by antennal club lighter in color than the previous segments.

Etymology. The specific name is derived from the name of similar Dianous aerator Puthz, 2016 .

Figures

FIGURES 1–6. Habitus of the species of the Dianous aereus complex. 1 D. vietnamensis 2 D. rougemontianus 3 D. ruginosus 4 D. aerator 5 D. pseudaerator 6 D. brevicornis. Scale bars: 1 mm.

FIGURES 13–22. Sexual characters. 13–18 male sternite VII 19, 20 male sternite VIII 21 female sternite VIII 22 valvifer 13 Dianous vietnamensis 14 D. rougemontianus 15 D. ruginosus 16 D. aerator 17, 21, 22 D. pseudaerator 18, 20 D. brevicornis. Scale bars: 0.25 mm.

FIGURES 31–37. Aedeagus. 31 D. ruginosus 32, 33 D. aerator 34, 35 D. pseudaerator 36, 37 D. brevicornis. Scale bars: 0.25 mm.