Abstract
Traits important for mate choice and behavioural isolation are predicted to be under strong stabilising selection within species. These traits can also exhibit variation at the population level that can be driven by both neutral and adaptive evolutionary processes. Here, we investigate the patterns of androconial and genital chemical profile inter- and intra-specific divergence in mimetic Heliconius butterflies across the Neotropics. We find evidence for species-specific compounds which are consistent across a large geographic range, suggesting a role in behavioural species isolation. At the population level, we also find chemical bouquet differences, but, contrary to predictions, these do not appear to be stronger in sympatric populations of co-mimetic species. The strength of the correlation between chemical and the genetic divergence varies between species and is generally stronger for genital chemical profiles than for androconial chemical divergence. Together, these patterns support that multiple evolutionary processes shape the evolution of chemical bouquets in Heliconius butterflies.