In our work, using the analysis of DNA barcodes and morphology (wing color, male genitalia, sphragis shape in females), we show that the group of species close to P. mnemosyne is represented by two phylogenetic lineages, the western and eastern ones. The eastern lineage includes P. stubbendorfii, P. glacialis and P. hoenei. The western lineage includes three morphologically similar species, P. mnemosyne (Western Eurasia), P. turatii (southwestern Europe) and P. nubilosus stat. nov. (Turkmenistan and NE Iran), as well as P. ariadne (Altai). The latter species differs from the rest of the group in the presence of red spots on the wings. Parnassius mnemosyne s.s. is represented by four differentiated mitochondrial clusters that show clear association with specific geographic regions. We propose to interpret them as subspecies: P. mnemosyne mnemosyne (Central and Eastern Europe, N Caucasus, N Turkey), P. mnemosyne adolphi (the Middle East), P. mnemosyne orientalis (Tian Shan) and P. mnemosyne gigantea (Gissar-Alai in Central Asia). We demonstrate that in P. ariadne the red spots on the wing evolved as a reversion to the ancestral wing pattern. This reversion is observed in Altai, where the distribution areas of the western lineage, represented by P. ariadne, and the eastern lineage, represented by P. stubbendorfii, overlap. These two species hybridize in Altai, and we hypothesize that the color change in P. ariadne is the result of reinforcement of prezygotic isolation in the contact zone. Lectotype of Parnassius mnemosyne var. nubilosus Christoph, 1873 is designated.

The need for multi-gene analysis in evolutionary and taxonomic studies is generally accepted. However, sequencing of multiple genes is not always possible. For various reasons, short mito-chondrial DNA barcodes are the only source of molecular information for some species in many genera, although multilocus data are available for other species of the same genera. In particular, such a situation exists in the species-rich butterfly subgenus Polyommatus (Agrodiaetus). Here, we analysed partitioning of this subgenus into species groups by using three data sets. The first data set was represented by short mitochondrial DNA barcodes for all analysed samples. The second and third data sets were represented by combination of short mitochondrial DNA barcodes for a part of the taxa with longer mitochondrial sequences COI+tRNA-Leu+COII (data set 2) and with longer mitochondrial COI+tRNA-Leu+COII and nuclear 5.8S rDNA+ITS2+28S rDNA sequences (data set 3) for the remaining species. We show that DNA barcoding approach (data set 1) failed to reveal the taxonomic structure resulting in numerous polytomies in the phylogenetic tree ob-tained. Combined analysis of the mitochondrial and nuclear sequences (data sets 2 and 3) re-vealed the species groups and position within these species groups even for the taxa for which only short DNA barcodes were available.