Molecular systematics of the arctiine tribe Syntomini (Lepidoptera, Erebidae)

The Old World tribe Syntomini is the most neglected of the three major groups of the subfamily Arctiinae - the most megadiverse lineage (c. 11 000 species) of the superfamily Noctuoidea, comprising about a quarter of its entire species diversity. In none of the previous morphogenetic studies was Syntomini (which are often conspicuously spotted, aposematic moths) sampled adequately enough to provide information about the tribe's systematic diversity and relationships above species level. As such data are of crucial importance for a comprehensive understanding of arctiine diversity and evolution, we have investigated the relationships of the major lineages of Syntomini based on up to eight mitochondrial and nuclear genes and 91 species, representing 39 genera. We cover most of the known genera and major geographic regions, including, for the first time, Madagascar, where there is a significant syntomine radiation. We find that the thyretines, in particular, which are restricted to the Afrotropical region, are paraphyletic. As a result we propose to treat Thyretina syn.n. (Thyretini sensu Przybylowicz, 2009) as an artificial assemblage and synonymize it under Syntomini. Thyretes Boisduval and Pseudothyretes Dufrane stand on their own close to the Madagascan radiation, whereas all but one of the Madagascan syntomines comprise a monophylum, with the genus Fletcherinia Griveaud instead being related to at least one species of Ceryx Wallengren in Africa. Also surprising from a biogeographical point of view is that the genus Dysauxes Hubner, which includes the European Handmaiden moth, is nested within the Madagascan radiation. Our study also makes it clear that much more detailed studies are needed to revise not only Ceryx from Asia and Africa but the Afrotropical syntomine genera, many of which do not form clades in our phylogenetic reconstruction, and to further inventory the diversity that is present in the Afrotropics. Based on our results, we consider Thyretarctia Strand stat. rev., Daphaenisca Kiriakoff stat.n. and Callobalacra Kiriakoff stat.n. as valid genera. We also move Anapisa Kiriakoff and return Meganaclia Aurivillius and Nacliodes Strand to Syntomini.