Acidota dawai Z. Peng & X. Chen, 2023

Chen, Xi, Xu, Yong-Qiang & Peng, Zhong, 2023, A new species and a new provincial record of the genus Acidota Stephens from China (Coleoptera, Staphylinidae, Omaliinae), ZooKeys 1173, pp. 297-305 : 297

Acidota dawai Z. Peng & X. Chen sp. nov.

Figs 2B , 3

Type material.

Holotype: ♂, labelled 'China: Xizang Prov., Linzhi City, Mt. Sejila, near Shejiema, 29°36 ’50” N 94°41 ’34” E, alt. 4340 m, 05.VII.2018, Chen, Peng & Shen leg.' <white rectangular label, printed> / 'HOLOTYPE: Acidota dawai sp. n., Peng & Chen des. 2023' <red rectangular label, printed> (SNUC). Paratypes: 5 ♂♂, 7 ♀♀: same data as holotype / 'PARATYPE: Acidota dawai sp. n., Peng & Chen des. 2023' <yellow rectangular label, printed> (SNUC).

Description.

Measurements (in mm) and ratios: TL: 6.00-6.91; FL: 3.15-3.60; HL: 0.43-0.46; HW: 0.70-0.74; AnL: 1.56-1.75; PL: 0.93-0.98; PW: 1.20-1.24; EL: 1.22-1.33; EW: 1.32-1.42; AL: 0.77-0.84; HW/HL: 1.59-1.64; HW/PW: 0.58-0.60; HL/PL: 0.46-0.48; PW/PL: 1.26-1.28; EL/PL: 1.27-1.34.

Body (Fig. 2B ) blackish brown, antennae paler, basal portions of femora, apical portions of tibiae and tarsi brown to light brown.

Head subtriangular, distinctly transverse; clypeus convex; eyes very convex, about 1.73 times as long as temples (holotype); ocelli distinct, distance between ocelli 1.9 times as long as distance between ocellus and posterior margin of eye (holotype). Punctation of forebody coarse and dense; pubescence moderately long and dense. Antennae (Fig. 1C ) slender, length × width (in mm) of antennomeres 1-11 (holotype): 0.20 × 0.10: 0.14 × 0.07: 0.14 × 0.07: 0.14 × 0.07: 0.13 × 0.08: 0.13 × 0.08: 0.13 × 0.08: 0.13 × 0.10: 0.11 × 0.11: 0.11 × 0.12: 0.18 × 0.12.

Pronotum slightly transverse, widest in the middle; disc convex, without impression; punctures similar to that of head, but more distinct; pubescence moderately long and dense.

Elytra slightly convex, 1.1 times as wide as long; punctation coarser and sparser than that of pronotum; pubescence distinctly sparser than that of pronotum. Hind wings well developed.

Abdomen slender, widest at segment V, evenly narrowing posteriorly. Abdominal tergites with fine and dense punctation, and short decumbent pubescence, denser on apical tergites; tergites IV-V with a pair of tomentose spots in middle, spots on tergite V smaller and less transverse.

Male. Posterior margin of abdominal tergite VIII (Fig. 3C ) and sternite VIII (Fig. 3D ) truncate. Aedeagus as in Fig. 3E, F ; median lobe indistinctly narrowed toward moderately wide with subacute apex; parameres symmetrical, wide, reaching apex of median lobe, each bearing two apical setae; internal sac wide and long, spirally folded in basal portion.

Female. Posterior margin of abdominal tergite VIII (Fig. 3A ) somewhat truncate. Posterior margin of abdominal sternite VIII (Fig. 3B ) rounded.

Distribution and natural history.

The type locality is situated in the Sejila Mountain to the east of Linzhi, south-eastern Xizang. Some of the specimens were sifted from rhododendron litter and humus in a rhododendron forest on a west slope near the mountain summit at an altitude of 4340 m (Fig. 3G ).

Etymology.

This species is dedicated to Mr Dawa, who supported us on our field trips.

Comparative notes.

Regarding the general shape of the body, aedeagus, and features of the punctation and pubescence, A. dawai is similar to dark-coloured specimens of the morphologically variable A. crenata , a widespread species in the Holarctic region. The new species can be distinguished from A. crenata by the distinctly more transverse head, longer antennomere 2, and the shapes of the slightly wider and shorter parameres, which are subparallel in the middle and gradually narrowing towards the apex (parameres of A. crenata are insignificantly narrower, moderately strongly narrowing apicad).

Figures

Figure 1. Habitus: A Acidota crenata (from Canada) B Acidota crenata japonica (Paratype). Scale bars: 1.0 mm.

Figure 2. Habitus: A Acidota crenata (from China) B Acidota dawai. Scale bars: 1.0 mm.

Figure 3. Acidota dawai A female tergite VIII B female sternite VIII C male tergite VIII D male sternite VIII E aedeagus in lateral view F aedeagus in ventral view G Zhi-Fei Cheng collecting Acidota dawai at Mt. Sejila, Xizang. Scale bars: 0.2 mm.