A new species of from Israel, with notes on taxonomy, cytogenetics, phylogeography and interspecific hybridization in the complex (Lepidoptera, Nymphalidae).

Specimens with intermediate morphology are often considered to be the result of ongoing interspecific hybridization; however, this conclusion is difficult to prove without analysis of chromosomal and/or molecular markers. In the butterfly genus , such an intermediacy can be detected in male genitalia, and is more or less regularly observed in localities where two closely related, presumably parental species are found in sympatry. Here I analyze a high altitude population from Mt. Hermon in north Israel and show that its male genitalia are clearly differentiated from those found in phenotypically similar and , but in some aspects intermediate between them. This hybrid-like population is unique because, although is present on Mt. Hermon, the true, low-altitude has never been reported from Israel. Cytogenetic analysis revealed no apomorphic chromosomal characters to distinguish the Mt. Hermon population from other known taxa of the and species groups. At the same time, DNA barcode-based phylogeographic study showed that this population is ancient. It was estimated to originate 1-1.6 million years ago in the Levantine refugium from a common ancestor with . Generally, the data obtained are incompatible with interpretation of the studied population as a taxon conspecific with or , or a swarm of recent hybrids between and , although the possibility of ancient homoploid hybrid speciation cannot be ruled out. I also argue that the name assigned to butterflies from north Lebanon cannot be applied to the studied taxon from Mt. Hermon. Here I describe this morphologically and ecologically distinct entity as a new species , and compare it with other taxa of the complex.