One Species, Hundreds of Subspecies? New Insight into the Intraspecific Classification of the Old World Swallowtail (Papilio machaon Linnaeus, 1758) Based on Two Mitochondrial DNA Markers

SIMPLE SUMMARY: The Old World swallowtail Papilio machaon Linnaeus, 1758 is one of the most iconic butterflies, and like many butterflies, it was, and still is, a popular collecting item. P. machaon is characterised by a very high individual variability, which, combined with the great interest of collectors and amateur entomologists, has been converted into the descriptions of over 100 colour forms, aberrations and subspecies. The present study examines two mitochondrial DNA sequences (mtDNA) of 16S rDNA, and cytochrome b of 87 specimens of P. machaon collected in the entire Palearctic Region and their correlation with intraspecific classification. The results of our research showed that the proposed intraspecific classification by different authors does not correlate with the variability in mitochondrial DNA sequences. ABSTRACT: The Old World swallowtail Papilio machaon Linnaeus, 1758 is one of the most well-known and most characteristic members of the family Papilionidae. Over the past two centuries, the butterfly has been the subject of many studies. P. machaon is characterised by a tendency to change the wing colour pattern. In turn, due to the great interest of collectors and amateur entomologists, these studies have been converted into the description of over 100 colour forms, aberrations and subspecies. In this study, mitochondrial DNA (mtDNA), 16S rDNA and cytochrome b sequences were used to examine the correlation between the intraspecific classification and genetic structure of P. machaon. The study used 87 specimens from 59 different localities covering the geographic distribution of this species in the Palaearctic. The phylogenetic relationships within and between the Old World swallowtail subspecies showed that the intraspecific classification proposed by various authors does not correlate with the variability in mitochondrial DNA sequences. In addition, populations occurring at the species distribution borders in the Palaearctic Region (i.e., Japan, Kamchatka, Morocco and Sakhalin) are genetically distinct from other species.