A taxonomic revision of the Formica subpilosa Ruzsky, 1902 group (Hymenoptera: Formicidae)

Seifert, B.; Schultz, R.

Abstract: The members of the West to Central Asian Formica subpilosa group were investigated by means of numeric morphologybased alpha-taxonomy (NUMOBAT). 18 phenotypic characters were described on the basis of 201 nest samples comprising 591 worker individuals. Five morphospecies were distinguished: Formica subpilosa Ruzsky, 1902, F. litoralis KUZNETZOV-UGAMSKY, 1926, F. clarissima Emery, 1925, F. pamirica Dlussky, 1965, and F. kashmirica STÄRCKE, 1935. A leave-one-out cross-validation discriminant analysis (LOOCV-DA) separated the first four species with an error indication of 0% and allocated all available type series near to the cluster centres with a-posteriori probabilities of p = 1.000. The heterospecificity of Formica kashmirica, represented only by the type sample and not reasonably testable by a Da, is justified by a character combination not found in any of the other species. Formica clarissima, F. kashmirica, F. litoralis, and F. pamirica are elevated to species rank. Formica litoralis and F. pamirica are parapatric sibling species – there seems to be no morphological convergence with falling geographic distance but the question of possible hybridisation in contact zones cannot be answered by the existing data. Formica cinerea var. bipilosa Karavajev, 1926 was confirmed to be a junior synonym of F. subpilosa. The separation of the Palaearctic Serviformica species with reddish pigmentation into a Formica cinerea Mayr, 1853, a F. rufibarbis Fabricius, 1793, and a F. subpilosa group is confirmed by a discriminant analysis. All species are depicted and a simplified identification key is given. Species of this group prefer habitats with exposed alluvial, lacustrine or aeolian soils and sparse plant cover. The F. subpilosa group ecologically replaces the F. cinerea group in Central Asia.

Myrmecol. News 12: 67-83; printable