Repeated evolution in overlapping mimicry rings among North American velvet ants

Mullerian mimicry, in which two or more harmful species share a similar appearance for mutual benefit, is a widely appreciated, yet relatively uncommon natural phenomenon. Although Mullerian mimicry occurs in vertebrates, most studies are focused on tropical, herbivorous invertebrates. Here we identify a large Mullerian mimicry complex in North American velvet ants (Hymenoptera: Mutillidae). These are conspicuous, diurnal parasitoids of bees and wasps that defend themselves with a powerful sting. We investigate morphological and genetic variation and ask whether morphological similarities are the result of convergent evolution or shared ancestry. We find that 65 species in the velvet ant genus Dasymutilla can be placed into one of six morphologically distinct and geographically delimited mimicry rings. Mullerian colour patterns are primarily the result of independent evolution rather than shared, phylogenetic history. These convergent colour syndromes represent one of the largest known Mullerian mimicry complexes yet identified, particularly in the Northern Hemisphere.