Molecular and Morphological Inference of Three Cryptic Species within the Merodon aureus Species Group (Diptera: Syrphidae)

TheMerodon aureusspecies group (Diptera: Syrphidae: Eristalinae) comprises a number of different sub-groups and species complexes. In this study we focus on resolving the taxonomic status of the entity previously identified asM.cinereusB, here identified asM.atratusspecies complex. We used an integrative approach based on morphological descriptions, combined with supporting characters that were obtained from molecular analyses of the mitochondrial cytochrome c oxidase I gene as well as from geometric morphometry of wing and surstylus shapes and environmental niche comparisons. All applied data and methods distinguished and supported three morphologically cryptic species:M.atratusstat. nov.,M.virgatussp. nov.andM.balkanicussp. nov., which constitute theM.atratusspecies complex. We present an identification key for the sub-groups and species complexes of theM.aureusspecies group occurring in Europe, describe the taxa and discuss the utility of the applied methods for species delimitation. The estimated divergence times for the species splits of these taxa coincide with the Pleistocene Günz-Mindel interglaciation and the Great interglaciation (between the Ris and Mindel glacial periods).