Müllerian mimetic radiation of Delias butterflies (Lepidoptera: Pieridae) in Bali and Timor

Mimicry rings are present among Delias butterflies, and those butterflies are also considered to be mimetic models of other lepidopteran insects; however, experimental evidence for their unpalatability to predators is limited. In Bali and Timor, a total of three mimicry rings of Delias species are present; particularly, male and female D. lemoulti join different rings in Timor. The present study examined the unpalatability of Delias in Bali and Timor to the caged avian predator Pycnonotus aurigaster. The birds ate eight Delias species in similar numbers, and ate the palatable butterfly Mycalesis horsfieldii much more frequently than Delias butterflies. The result suggests that the three mimicry rings of Delias species in Bali and Timor are Müllerian rather than Batesian. Based on previous findings on their phylogenetic relationships, the Müllerian mimicry rings of Delias in Bali and Timor are suggested to have emerged through the convergent evolution and phylogenetic constraints of wing color patterns. In the D. hyparete species group, mimetic radiation may have occurred between Bali and Timor.