Formica gagatoides Ruzsky, 1904, and Siberian F. kozlovi Dlussky, 1965 (Hymenoptera: Formicidae); Two or One Species?

Abstract

Ants of the genus Formica play an important role in biogenesis by participating in various processes, including the formation of complex trophic networks. The role of ants in an ecosystem depends on their species and geographic population, which can be difficult to identify. Formica gagatoides with a wide range and F. kozlovi are among some examples. The question is whether the Siberian populations of F. kozlovi really belong to this species or are local populations of F. gagatoides. Based on the materials collected in Russia (Murmansk Region, the north of the Krasnoyarsk Territory, Altai, Far East), a morphological analysis (key diagnostic features) and molecular genetic analysis (COI, ITS1, D2 28S) were carried out. In all localities, there were individuals with pure (gagatoides, kozlovi) and mixed (gagatoides/kozlovi) morphotypes, with the exception of the Magadan Region, where the kozlovi morphotype was absent. According to the phylogenetic trees, F. gagatoides formed separate geographical branches, with the Siberian F. kozlovi being close and clearly conspecific to the Asian branch of F. gagatoides. A relatively high COI divergence, along with some differences in the ITS1 sequences, between the Asian and European F. gagatoides raises the question about the conspecificity of the Asian and European branches of this species.