Geostiba (Sibiota) pambakica ASSING, 2016

Assing, Volker, 2017, On the Geostiba fauna of Armenia (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 49 (2), pp. 1075-1092 : 1081

Geostiba (Sibiota) pambakica ASSING, 2016 ( Figs 1-13 , Map 3 )

M a t e r i a l e x a m i n e d: Armenia:233 [both with single median tubercle on tergite VII], 4♀♀, road Berd – Ijevan , 40°52'N, 45°18'E, 1350 m, beech forest margin, litter and roots sifted, 30.VI.2017, leg. Assing & Schülke (cAss) ; 1633 [one of them with single median tubercle on tergite VII), 23♀♀, pass road E Ijevan, 40°52'N, 45°13'E, 1790 m, forest with old Quercus and Carpinus, litter and roots sifted, 6.VII.2017, leg. Assing & Schülke (cAss, MNB).

C o m m e n t: The previously known distribution of G. pambakica was confined to three geographically close localities in the Pambaki range. The new records show that the species is distributed northeastwards to the mountains east of Ijevan ( Map 3 ).

An examination of the material listed above revealed a remarkable intraspecific variation of the male secondary sexual characters. The pair of carinae on the male tergite VII may be completely obsolete (in small males), more or less pronounced and separated (most males), more or less distinctly connected posteriorly by a transverse bridge, or (both males from the former and one from the latter of the above localities) even be completely fused and form a single tubercle (similar to the condition in males of G. unituber ). Such extreme variation was not observed in the type material. The specimens from the mountains to the east of Ijevan are additionally distinguished from those from the Pambaki range by slightly larger average size, slightly darker coloration, and on average more pronounced sutural carinae on the male elytra. However, significant differences in the primary sexual characters ( Figs 1-13 ) were not observed, suggesting that the – geographically rather distant - populations from the environs of Ijevan and from the Pambaki range are conspecific.

Figures

Map 3: Distribution of Sibiota species in Armenia: G. pambakica (white circles); G. tigrani (black circles); G. unicuneata (white diamonds), G. immutata (black star), G. meghruica (white triangles); G. sp. 1 (black triangle); G. sp. 2 (white star).

Figs 1-13: Geostiba pambakica from road Berd – Ijevan (1-2, 9-10) and from pass road E Ijevan (3-8, 11-13; 8: male with single median tubercle on tergite VII): (1-8) median lobe of aedeagus in lateral and in ventral view; (9-13) spermatheca. Scale bars: 0.1 mm.