Ceylon Palmfly (Elymnias singhala)
Studies have shown the relationship between the geographic distribution of consumers (butterflies) and their hosts (food plants) have a triangular relationship. Though butterfly species that feed on more widely distributed hosts are themselves more widely distributed, some species have much more restricted ranges than their hosts have. Experiments with caged animals have conclusively demonstrated that substantial protection from predators if gained mimic butterfly.
Elymnias hypermnestra male mimics Euploea spp whilest its female mimics Danaus chrysippus. Both male and female of Elymnias singhala mimic Euploea spp. Abundance of male vs. female and model vs. mimic were observed for two years. Island wide distribution, life history, habitat, and behavior of both species were also studied.
E. hypermnestra female closely mimics its model than its male do. Both sexes of E. singhala easily overlook their model than E. hypermnestra male, in flight and in size. E. hypermnestra distributed all over the island. Record of endemic and threatened butterfly Elymnias singhala were confirmed after six decades with the first record of its life history. E. singhala restricted to undisturbed forest patches of Caryota urens, Calamus rotang and Calamus zeylanicus in wet zone highland but the absence of the species after extensive survey in similar habitats reveal that E. singhala is more local. E. singhala is rather shy butterfly inhabits dark dense forests which feeds on over-ripped fruits etc.. E. singhala often fly as couple and individual female can be seen hovering host plats. E. hypermnestra female always flies individually and less abundant than its male. E. hypermnestra males pare have a ‘dance’ or ‘fight’ possibly for territory. Perhaps pare of males share the same territory because both chase other butterflies together and that ‘couple dance’ never aggressive. Immediate conservation actions such as habitat restoration and transplanting should be tested for E. singhala.