Mimetic females do not bear reproductive costs: Challenging the sexual selection hypothesis in female-limited mimetic polymorphism in butterflies

Batesian mimicry has been regarded as classical evidence of adaptation by natural selection, in which a palatable species avoids predation by resembling unpalatable species. In some butterfly species, Batesian mimicry is female-limited and mimetic females coexist with male-like (nonmimetic) females. Why do nonmimetic females continue to exist despite the possible differential predation pressure? One possible hypothesis is a trade-off between the anti-predatory defense and mating success. Specifically, mimetic females may be less attractive to conspecific males as they look like heterospecific butterflies. However, empirical studies based on behavioural data have shown mixed results. Here, we directly investigated female mating frequency by counting spermatophores and compared it between mimetic and nonmimetic females in a Batesian mimetic butterfly, Papilio polytes. These are the datasets of field sampling, spermatophore counts, wing brightness, and forewing images of female P. polytes.