Leptusa (Drepanoleptusa) desculpens, Assing, 2021

Assing, Volker, 2021, New species and additional records of Leptusa from the Palaearctic region, with a focus on the faunas of China and the Caucasus region (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 71 (1), pp. 103-126 : 120

Leptusa (Drepanoleptusa) desculpens spec. nov.

urn:lsid:zoobank.org:act:A3342BAF-F31E-43E6-9636-8250A85FBD97

( Figs 7 , 18 , 61–64)

Type material: Holotype : “ CHINA, Yunnan, SE Pingbian, 22°54'31"N, 103°41'44"E, 2100 m, primary subtropical broad-leaved forest, litter sifted, 27.VIII.2014, leg. M. Schülke [CH14-22] / Holotypus  Leptusa desculpens sp. n. det. V. Assing 2020” ( MNB). Paratype : same data as holotype, but “ 28.VIII.2014, ... [ CH 14- 22a]” (cAss) .

Etymology: The specific epithet is the present participle of the Latin verb desculpere (to chisel) and alludes to the chisel-shaped internal structure of the aedeagus.

Description: Body length 2.1–2.4 mm; length of forebody 0.9–1.0 mm. Habitus as in Fig. 7 . Colouration: forebody brown to dark-brown with the humeral angles and the posterior margins of the elytra reddish-yellow; legs yellowish; antennae brown with the basal three antennomeres and antennomere XI reddish.

Head ( Fig. 18 ) approximately as long as broad; punctation very coarse and dense, interstices reduced to narrow ridges. Eyes shorter than postocular region in lateral view. Antenna incrassate apically; antennomeres IV weakly transverse, V–X increasing in width and increasingly transverse, and X approximately twice as broad as long.

Pronotum ( Fig. 18 ) approximately 1.2 times as broad as long and 1.2 times as broad as head; maximal width in anterior half; posterior angles marked; punctation similar to that of head, but somewhat less coarse.

Elytra ( Fig. 18 ) approximately 0.8 times as long as pronotum, extensively impressed; punctation very coarse, dense and asperate. Hind wings reduced.

Abdomen approximately as broad as elytra; tergites III–V with anterior impressions densely and coarsely punctate; punctation distinct and moderately fine, dense on anterior tergites and sparser on posterior tergites; interstices glossy, without distinct microsculpture; posterior margin of tergite VII without palisade fringe; tergites VII and VIII sexually dimorphic.

: tergites VII and VIII each with oblong postero-median tubercle (Fig. 63); posterior margin of sternite VIII obtusely produced in the middle (Fig. 64); median lobe of aedeagus approximately 0.3 mm long, shaped as in Figs 61–62; internal structures of distinctive shapes; apical lobe of paramere distinctly oblong.

: unknown.

Comparative notes: This species is readily distinguished from all other congeners recorded from China by the distinctive internal structures of the aedeagus and additionally by the combination of small size, slender habitus, and conspicuously coarse punctation of the forebody.

Distribution and natural history: Leptusa desculpens is currently the sole representative of the genus known from Southeast Yunnan. The specimens were sifted from litter in a primary broad-leaved forest in Dawei Shan, Yunnan, at an altitude of 2100 m.

Figures

Figs 1–8: Male habitusof Leptusaspp.1 – L.excisa; 2 – L.grandipennis; 3– L.auriculata; 4– L.gonggana; 5– L.emeiana; 6 – L. jizuica;

Figs 9–18: Male habitus (9–11) and forebody (12–18) of Leptusa spp. 9, 15 – L. habana; 10 – L. monscangi; 11 – L. pathibarana; 12 – L. excisa; 13 – L. grandipennis; 14 – L. gonggana; 16 – L. auriculata; 17 – L. jizuica; 18 – L. desculpens. Scale bars:9–16: 1.0 mm; 17–18: 0.5 mm.