The complex of butterfly taxa close to Melitaea didyma includes the traditionally recognized species Melitaea didyma, Melitaea didymoides and Melitaea sutschana, the taxa that were recognized as species only relatively recently (Melitaea latonigena, Melitaea interrupta, Melitaea chitralensis and Melitaea mixta) as well as numerous described subspecies and forms with unclear taxonomic status. Here analysis of mitochondrial DNA barcodes is used to demonstrate that this complex is monophyletic group consisting of at least 12 major haplogroups strongly differentiated with respect to the gene COI. Six of these haplogroups are shown to correspond to six of the above-mentioned species (Melitaea didymoides, Melitaea sutschana, Melitaea latonigena, Melitaea interrupta, Melitaea chitralensis and Melitaea mixta). It is hypothesized that each of the remaining six haplogroups also represents a distinct species (Melitaea mauretanica, Melitaea occidentalis, Melitaea didyma, Melitaea neera, Melitaea liliputana and Melitaea turkestanica), since merging these haplogroups would result in a polyphyletic assemblage and the genetic distances between them are comparable with those found between the other six previously recognized species.
Keywords: Biodiversity; COI; Nymphalidae; butterflies; cryptic species; mitochondrial DNA; phylogeography; taxonomy.