Dianous lilizheni, Tang & Wang & Szx & Eos, 2018

Tang, Liang, Wang, Wei, Szx, Olympus & Eos, Canon, 2018, Notes on the Dianous luteoguttatus complex with description of a new species (Coleoptera: Staphylinidae), Acta Entomologica Musei Nationalis Pragae 58 (1), pp. 237-242 : 239-242

Dianous lilizheni sp. nov.

( Figs 6 , 18–22 )

Type material. HOLOTYPE. CHINA: SICHUAN:, glued on a card with labels as follows: “ China: Sichuan Prov., Emeishan , Qingyinge- - Hongchunping , 7.VIII.2011, Huang Hao leg.” “ Holotype / Dianous lilizheni / Tang & Wang” [red handwritten label] ( SHNU). PARATYPES. 1, Emeishan, Changshou Bridge, 29 ° 33 ′ N 103 ° 22 ′ E, alt. 1400 m, 26.vii.2012, Peng, Dai & Yin leg. (cPut). YUNNAN: 1, Jinghong City, Nabanhe N. R., Bengganghani, 14.i.2004, Li & Tang leg. ( SHNU )

Description. Head and abdomen black, pronotum and elytra dark brown to blackish with strong plumbeous luster, antennae dark brown with club slightly lighter, legs blackish with tibiae and tarsomeres slightly lighter, trochanters brownish, maxillary palpi with segment I yellowish, segment II brown and segment III dark brown. Pubescence silvery, distinct on head and abdomen, nearly invisible on pronotum and elytra.

BL: 6.3–6.6 mm; FL: 3.1–3.4 mm. HW: 1.24–1.30 mm, PL: 0.95–0.99 mm, PW: 0.85–0.89 mm, EL: 1.33–1.43 mm, EW: 1.15–1.29 mm, SL: 1.10–1.18 mm.

Head 0.98–1.08 times as wide as elytra; interocular area with deep longitudinal furrows, median portion as wide as the side portions and convex posteriorly, extending far beneath the level of inner eye margins; punctures round to oval, those of anterior potion more or less confluent, those of the remaining area well delimited, diameter of punctures slightly wider than medial ommatidia of eyes; interstices shallowly reticulated except those on median portion, which are smooth, interstices at frons and along the furrows narrower than half the diameter of punctures, those on the remaining portions as wide to moderately wider than diameter of punctures. Antennae very long, when reflexed, reaching basal half of the elytra.

Pronotum 1.09–1.12 times as long as wide; disk uneven with transverse impression near anterior margin, two deep pits at about middle, short longitudinal furrow along the middle, two distinct impressions near posterolateral margin and transverse impression near posterior margin; punctures slightly larger than those of head, partially well delimited, those at anterior and posterior impressions strongly and transversely confluent; interstices smooth, 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 two or three punctures.

Elytra 1.09–1.15 times as long as wide; humeral impressions distinct; punctation strongly confluent, interstices smooth and rugae-like, those of posteromedian area strongly vorticose forming a complete rosetta.

Metasternum with median area impressed, sparsely punctate and with dense microsculpture, diameter of punctures slightly wider than medial ommatidia of eyes.

Legs slender, metatarsi longer than 5/6 of hind tibiae, metatarsomere I distinctly longer than the following three segments combined, metatarsomere IV simple with long apical setae except for one paratype from Sichuan with metatarsomere IV slightly emarginate at apex.

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, smaller than ommatidia of eyes, those on tergite VIII larger, as large as 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 slightly impressed posteromedially with shallow emargination along posterior margin of the impression, pubescence of impression distinctly longer; 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. 22 ) with apicolateral projections very long, situated sublaterally rather than laterally; tergite X ( Fig. 18 ) with posterior margin broadly rounded. Aedeagus ( Figs 20, 21 ) slender, median lobe roundly prominent at apex with two sharp longitudinal ridges (dotted line in Fig. 21 ) on dorsal side, internal sac with slender copulatory tube and small basal tube; parameres slightly bent inwards and ventrally, as long as median lobe, each with 15–17 setae on inner side of apical portion.

Female. Unknown.

Etymology. This species is named in honor of Dr. Li-Zhen Li, my dear mentor.

Distribution. China (Sichuan, Yunnan).

Remarks. The species is closely related to Dianous vorticipennis Puthz, 2005 from Yunnan, but can be distinguished from the latter by the sparser punctation of the interocular area and shorter elytra.

Figures

Figs 1–6. Habitus of the species of the Dianous luteoguttatus species complex. 1 – D. luteoguttatus Champion, 1919; 2 – D. cruentatus L. Benick, 1942; 3 – D. rimosipennis Puthz, 2005; 4 –D. depressifrons Puthz, 2016; 5 –D. vorticipennis Puthz, 2005; 6 – D. lilizheni sp. nov. Scale bars: 1 mm.

Figs 15–22. Male sexual characters. 15–17 – Dianous vorticipennis Puthz, 2005; 18–22 – D. lilizheni sp. nov.; 15, 20, 21 – aedeagus; 16, 22 – sternite IX; 17, 19 – sternite VIII; 18 – tergites IX and X. Scale bars: 0.25 mm.