Morphometric and molecular studies on the populations of the damselflies Chalcolestes viridis and C. parvidens (Odonata, Lestidae)


Morphometric and genetic differences were analysed for two closely related damselflies, Chalcolestes viridis and C. parvidens. A total of 305 male individuals were collected from six European countries (Austria, Croatia, Germany, Greece, Hungary and Portugal). Measurements from a total of 28 populations of C. viridis and C. parvidens and several intermediate forms were collected to determine if they can be definitely distinguished using simple morphometric characters. DNA sequences from two independent loci (nuclear ribosomal ITS region and mitochondrial cytochrome oxidase I gene) were analysed to test whether these taxa represent separate monophyletic groups as well as to compare the genetic distance with those found between well-accepted European Lestes species. Discriminant analysis revealed that C. viridis and C. parvidens are differentiated in morphometric space. Individuals with intermediate anal appendage traits overlapped with both C. viridis and C. parvidens which raised the possibility that they are merely subspecies of a single species. However, genetic analysis of both investigated DNA regions showed that the two Chalcolestes taxa did not share haplotypes, indicating their status as true species. Furthermore, they formed a monophyletic group separated from the investigated Lestes species, supporting the recognition of the genus Chalcolestes. The two Chalcolestes species are very closely related compared with European Lestes species, suggesting that their divergence occurred relatively recently.

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