Colour pattern diversity and evolution in Oriental velvet ants (Hymenoptera: Aculeata: Mutillidae)

Abstract

The Mutillidae (Hymenoptera: Aculeata) are a family of solitary ectoparasitoid wasps, famous for their sting and conspicuous coloration. The occurrence of Müllerian mimicry complexes has been demonstrated in both Africa and North America. Müllerian mimicry is the resemblance between several harmful species, advertising their defence to would-be predators by sharing a conspicuous colour pattern. Various colour patterns are known to occur in Oriental (Asian) velvet ants, but potential Müllerian mimicry complexes have not yet been inferred. We analysed the coloration of the females of 283 Oriental velvet ant species (52 genera), characterized by 12 phenotypic traits, and we identified shared colour patterns. Morphological differences between groups were tested using non-metric multidimensional scaling and permutational multivariate analysis of variance. We also inferred the geographical range of these colour patterns, and we investigated whether the shared patterns are the result of convergent evolution or common ancestry. We identified six distinct shared colour patterns, of which four can be associated with Müllerian mimicry. We also studied the position and shape of metasomal markings, and we found no association with mimicry rings. Our results improve the understanding of colour evolution in Oriental velvet ants and extend the previously described Müllerian mimicry complex to the south Asiatic landmass.