Taxonomy of European Eristalinus (Diptera: Syrphidae) based on larval morphology and molecular data

Abstract

The taxonomy of European Eristalinus syrphid flies is reviewed. New data on their life histories, biological notes and a key to species using pupal characters are provided. The larvae and puparia of Eristalinus taeniops (Wiedemann, 1818) and Eristalinus megacephalus (Rossi, 1794) are described for the first time, including new morphological characters of the thoracic respiratory process of all species. The morphology of the male genitalia of E. megacephalus is described and compared with that of E. taeniops. The results of our morphological studies of the male genitalia and molecular data (mitochondrial COI and nuclear 28S rDNA) do not support the traditional adult classification based on the patterning on the eyes (fasciate vs punctate). We present a phylogeny of the species based on molecular data. The molecular and morphological data indicate that the relationship between some species with punctate eyes and those with fasciate eyes may be closer than with other species with punctate eyes. Moreover the results of the molecular studies support two clades, which does not accord with the traditional arrangement of this group of Syrphidae. Accordingly we propose that the characters of male genitalia stated by Kanervo in 1938 (but subsequently largely ignored) for arranging the European species of the Eristalinus-Eristalodes-Lathyrophthalmus complex, are suitable for classifying these species.