Hidden in the wing dots: Disentangling mimetic sister species of butterflies (Riodinidae: Stalachtis) with an integrative approach

Abstract

The high resemblance between closely related mimetic species poses a challenge to taxonomists who describe and define these species. An emblematic example is found within Stalachtis Hübner, 1818 (Lepidoptera: Riodinidae), a small Neotropical genus of brightly colored butterflies engaged in mimicry rings. Its systematic position within Riodinidae is difficult to define based on morphology alone, and while its taxonomy is inflated due to intraspecific color polymorphisms, phenotypic variation might be concealing cryptic species. Thus, we examined the subspecific diversity within S. phlegia (Cramer, 1779) through an integrative approach based on both molecular and morphological data, aiming to investigate taxon limits. Both morphology and molecular data support the status of S. phlegia and Stalachtis susannastat. rev. as distinct species. S. susannastat. rev. is a medium sized butterfly with an orange-black wing color pattern with a few white dots. Furthermore, S. susannastat. rev. has no subspecies, and is endemic to the Atlantic Forest, while the four subspecies within S. phlegia are widely distributed throughout the Amazon, the Cerrado savanna and in parts of the Atlantic Forest. We consider S. phlegia a promising model for studies of the effect of deforestation on mimetic color patterns in the Amazon–Cerrado transition.