Atheta (Atheta) brevapicalis, Assing & Vogel, 2017

Assing, Volker & Vogel, Jürgen, 2017, On some Athetini from Armenia and adjacent regions (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 49 (1), pp. 341-368 : 342-343

Atheta (Atheta) brevapicalis nov.sp. ( Figs 1-6 , 11-13 )

T y p e m a t e r i a l: Holotype 3: " ARMENIA [39] - 25 km SW Kapan, 39°04'01''N, 46°16'10''E, 2150 m, near stream, sifted, 10.VII.2016, V. Assing / Holotypus 3 Atheta brevapicalis sp. n. det. V. Assing 2017" (cAss). Paratypes: 13, 1♀: same data as holotype (cAss).

E t y m o l o g y: The specific epithet (adjective: with short apex) alludes to the apically short ventral process of the aedeagus, one of the characters distinguishing this species from the similar A. pechlaneri SCHEERPELTZ, 1933 .

D e s c r i p t i o n: Body length 3.6-4.7 mm; length of forebody 1.7-2.1 mm. Coloration: body black, elytra with or without an oblique and posteriorly dilated dark-yellowish band; legs with blackish-brown femora, yellowish-brown to brown tibiae, and yellowish tarsi; antennae black; maxillary palpi black with yellowish palpomere IV.

Head ( Fig. 1 ) approximately 1.1 times as broad as long; punctation very fine and moderately dense, sparse in median dorsal portion; microsculpture pronounced and composed of isodiametric meshes, rendering the dorsal surface nearly matt. Eyes distinctly longer than distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 2 ) 1.3-1.4 mm long; antennomeres IV smaller than V, weakly transverse or as long as broad, V-X of gradually increasing width and weakly transverse, X less than 1.5 times as broad as long, and XI longer than the combined length of IX and X, but shorter than the combined length of VIII-X.

Pronotum ( Fig. 1 ) 1.22-1.24 times as broad as long and 1.24-1.26 times as broad as head, broadest in anterior half; punctation fine and rather dense; microsculpture similar to that of head, composed of isodiametric meshes; pubescence directed anteriad along midline and predominantly transversely laterad in lateral portions (type I).

Elytra ( Fig. 1 ) approximately 1.05 times as long as pronotum; punctation very dense and fine; interstices with pronounced isodiametric microreticulation. Hind wings fully developed.

Abdomen narrower than elytra; tergites III-V with, tergite VI without anterior transverse impressions; punctation fine and moderately dense on anterior tergites, gradually becoming sparser and finer towards posterior tergites; microsculpture shallow, but distinct, composed of transverse meshes; tergite VIII subject to pronounced sexual dimorphism.

3: posterior margin of tergite VIII weakly concave and coarsely crenulate in the middle, on either side with a pronounced tooth ( Fig. 3 ); sternite VIII ( Fig. 4 ) longer than tergite VIII and with strongly convex posterior margin; median lobe of aedeagus 0.41-0.43 mm long and shaped as in Figs 5-6 .

♀: posterior margin of tergite VIII bisinuate ( Fig. 11 ); sternite VIII ( Figs 12-13 ) strongly transverse and slightly longer than tergite VIII, posterior margin indistinctly concave in the middle and with stout marginal setae; spermatheca similar to that of A. heymesi HUBENTHAL, 1913 (lost in the process of preparing it for photographing and consequently not figured).

C o m p a r a t i v e n o t e s: As can be inferred from the similar external and sexual characters, A. brevapicalis is closely allied to the widespread A. pechlaneri , which too has been collected in Armenia. It differs from this species by more distinct punctation of the abdomen, a smaller median lobe of the aedeagus with a shorter apex, a broader crista apicalis, and with internal structures of different shape ( A. pechlaneri : median lobe approximately 0.5 mm long, with a shorter crista apicalis in lateral view), and by the indistinct median concavity of the female sternite VIII (in A. pechlaneri with pronounced median excision). For comparison, the primary and secondary sexual characters of A. pechlaneri from Armenia are illustrated in Figs 7-10 , 14-16.

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The type locality is situated to the southwest of Kapan, South Armenia. The specimens were sifted from debris and litter of Salix near a stream at an altitude of 2150 m.

Figures

Figs 1-10: Atheta brevapicalis (1-6) and A. pechlaneri from Armenia (7-10): (1) forebody; (2) antenna; (3, 7) male tergite VIII; (4, 8) male sternite VIII; (5-6, 9-10) median lobe of aedeagus in lateral and in ventral view. Scale bars: 1-2: 0.5 mm; 3-4, 7-8: 0.2 mm; 5-6, 9-10: 0.1 mm.

Figs 11-16: Atheta brevapicalis (11-13) and A. pechlaneri from Armenia (14-16): (11, 14) female tergite VIII; (12, 15) female sternite VIII; (13, 16) postero-median portion of female sternite VIII. Scale bars: 11-12, 14-15: 0.2 mm; 13, 16: 0.1 mm.