Diversity and systematics of the Ibero-Balearic Eumerus (Diptera: Syrphidae): Providing tools for species identification

The syrphid genus Eumerus Meigen, 1822 is one of the most speciose in the world. In the Ibero-Balearic area (including Andorra and the Spanish side of the Pyrenees), recent taxonomic studies have increased the knowledge of Eumerus in Europe. A high taxonomic diversity together with a complex morphology make species identification difficult in this genus. The lack of updated and comprehensive tools to assist in the identification of species prompted the production of a dichotomous key to all Ibero-Balearic species of Eumerus and generation of DNA barcodes for ten species. In summary, a total of 37 species of Eumerus and nine species groups are reported in this geographical region. Eumerus caballeroi Gil Collado, 1929 is proposed as junior synonym of Eumerus nudus Loew, 1848 and the taxonomic status of Eumerus pauper Becker, 1921 is discussed. The first sequences of the 5´ region of the Cytochrome c oxidase subunit I gene (COI-5´) of Eumerus subornatus Claußen, 1989 and Eumerus truncatus Rondani, 1868 were obtained and their systematic positions corroborated.