Multivariate analysis of male genital structures in the Hipparchia semele-muelleri-delattini complex (Nymphalidae, Satyrinae) from the Balkans: How many taxa?

Two closely related Hipparchia taxa, Hipparchia delattini Kudrna, 1975 and H. semele muelleri Kudrna, 1975 have been described from the Balkans based on differences in male genital structure, compared to each other and to another nominal European taxon (H. semele Linnaeus, 1758). Subsequently, Kudrna (1977) synonymised both H. delattini and H. muelleri with H. volgensis (Mazochin-Porshnjakov, 1952). Application of multivariate statistical techniques on male genital data indicates a cline in several aspects of genital morphology linking these three taxa across Europe. Although clusters are repeatedly found that correspond with the three taxa, it is not possible to ascribe every individual specimen to one of the three Hipparchia taxa. Hipparchia muelleri is shown to occupy an intermediate position between H. semele and H. delattini. Generally, H. delattini is present in an area covering part of northern Greece and the central Balkans. H. semele is present in western Europe, the Balkans and down the western side of Greece. However, individual specimens that classify to H. delattini in the current analyses may occur much further west, where historically only H. semele has been, and there appears to be a correlation between putative taxa and altitude with H. delattini occurring at higher altitudes. It is suggested that genetic differentiation between these taxa has been maintained and enhanced during glacial-interglacial cycles. The results of this study are discussed in relation to other morphological characters and biogeography and require further testing with molecular data.