Atheta (Dimetrota) senticollis, 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 : 351-352

Atheta (Dimetrota) senticollis nov.sp. ( Figs 45-56 )

T y p e m a t e r i a l: Holotype 3: " ARMENIA - Dsegh env. (Tsover Lake), 40.950°N, 44.685°E, 1390 m, 23.V.2016, leg. A. & J. Müller / Holotypus 3 Atheta senticollis sp. n. det. V. Assing 2017" (cAss). Paratypes: 13 [teneral], 1♀: same data as holotype (cAss).

E t y m o l o g y: The specific epithet (from the Latin adjective sentus: rough, uneven) alludes to the uneven surface of the pronotum.

D e s c r i p t i o n: Body length 4.0- 4.5 mm; length of forebody 1.8-2.0 mm. Coloration: body completely black or with the elytra partly slightly paler, blackish-brown; legs with the femora yellowish-brown to dark-brown and the tibiae and tarsi dark-yellowish; maxillary palpi black with palpomere IV yellowish.

Head ( Figs 45-46 ) 1.06-1.09 times as broad as long; punctation fine and moderately dense, barely visible in the pronounced microreticulation, somewhat sparser in median dorsal portion. Eyes much longer than distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 47 ) approximately 1.2-1.3 mm long; antennomeres IV approximately as long as broad, V-X weakly transverse, X slightly less than 1.5 times as broad as long, and XI approximately as long as the combined length of IX and X.

Pronotum ( Figs 45, 48 ) 1.16-1.19 times as broad as long and approximately 1.2 times as broad as head, broadest in anterior half; dorsal surface somewhat uneven; punctation dense and distinct, coarser than that of head; microsculpture pronounced and composed of isodiametric meshes; pubescence directed anteriad along midline, predominantly diagonally postero-laterad and transversely laterad in lateral portions (type I).

Elytra ( Fig. 45 ) approximately as long as pronotum; punctation very dense and distinct, coarser than that of pronotum; interstices with isodiametric microreticulation. Hind wings fully developed. Metatarsomere I approximately as long as metatarsomere II; mesotibial seta approximately twice as long as width of mesotibia in the middle.

Abdomen narrower than elytra; tergites III-V with, tergite VI without shallow anterior transverse impressions; punctation rather dense and distinct on tergites III-V, sparser on tergites VII-VIII, somewhat intermediate on tergite VI; microsculpture distinct, composed of transverse meshes ( Fig. 49 ); tergite VIII subject to pronounced sexual dimorphism.

3: posterior margin of tergite VIII strongly modified, in the middle truncate and distinctly serrate, laterally with a pronounced spine-shaped process on either side ( Fig. 83 ); sternite VIII ( Fig. 85 ) with strongly convex posterior margin; median lobe of aedeagus ( Figs 52-53 ) 0.47 mm long; ventral process relatively long and slender, apically weakly curved in lateral view; internal sac with a pair of sickle-shaped structures and with other dark structures.

♀: posterior margin of tergite VIII slightly truncately produced and weakly concave in the middle ( Fig. 54 ); posterior margin of sternite VIII broadly convex and with a row of modified long and stout marginal setae ( Fig. 55 ); spermatheca with slender distal and proximal portions ( Fig. 56 ).

C o m p a r a t i v e n o t e s: In habitus, coloration, the shape of the female tergite VIII, and the shape of the spermatheca, this species strongly resembles A. bispinosa , from which it differs by an uneven surface of the pronotum, more distinct punctation of the pronotum and the elytra, a male tergite VIII of completely different shape, and by the shape and internal structures of the median lobe of the aedeagus.

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 near Dsegh in North Armenia at an altitude of 1390 m. The specimens were probably collected with a flight trap in a beech forest. One of the paratypes is teneral.

Figures

Figs 45-56: Atheta senticollis: (45) forebody; (46) median dorsal portion of head; (47) antenna; (48) median portion of pronotum; (49) median portion of tergite VII; (50) male tergite VIII; (51) male sternite VIII; (52-53) median lobe of aedeagus in lateral and in ventral view; (54) female tergite VIII; (55) female sternite VIII; (56) spermatheca. Scale bars: 45, 47: 0.5 mm; 50-51, 54-55: 0.2 mm; 46, 48-49, 52-53, 56: 0.1 mm.

Figs 71-84: Atheta semialba: (71) male tergite VIII; (72) male sternite VIII; (73-76) median lobe of aedeagus in lateral and in ventral view; (77-78) female tergite VIII; (79) female sternite VIII; (80- 84) spermatheca. Scale bars: 71-72, 77-79: 0.2 mm; 73-76, 80-84: 0.1 mm.

Figs 85-99: Atheta abscisa: (85) male tergite VIII; (86) male sternite VIII; (87-90) median lobe of aedeagus in lateral and in ventral view; (91) female tergite VIII; (92) female sternite VIII; (93-99) spermatheca. Scale bars: 85-86, 91-92: 0.2 mm; 87-90, 93-99: 0.1 mm.