How simple bioacoustic techniques help to resolve taxonomic problems: The case of birch-feeding Oncopsis-leafhoppers (Hemiptera: Cicadellidae) in Europe

European Oncopsis leafhoppers are taxonomically difficult species because of limited morphological characters for species identification. Four Oncopsis species are associated with Betula spp. Previous investigations from Britain using bioacoustics showed that the nominal species Oncopsis flavicollis consists of at least three sibling species. But due to lack of further studies the taxonomic state of these sibling species has never been clarified to date. In the last decades bioacoustic techniques became increasingly important in insect taxonomy. All leaf- and planthoppers produce substrate transmitted acoustic signals in contrast to the loud and prominent airborne songs of cicadas. Closely related species tend to differ clearly in their songs even though they show no or only week morphological differences. With this part of our study we have clarified the biotaxonomic situation, the host plant association and distribution of all European Oncopsis species associated with tree birches using relatively simple bioacoustic recording techniques. After recording the animals are still available for molecular and morphological studies. Finally it will be interesting to see if animals, which have different songs, do also differ in their DNA sequences. In the end the results obtained from the three different methods will be assembled for the species diagnosis and for the reconstruction of the phylogeny of the European birch feeding Oncopsis leafhoppers.