抄録
To clarify the chemical basis for the differential oviposition by two swallowtail butterflies, Papilio protenor and P. xuthus, on 4 typical host plants of Rutaceae-feeding Papilio species in Japan, Citrus unshiu, Fagara ailanthoides, Phellodendron amurense and Orixa japonica, females' responses to methanolic extracts and partitioned fractions from these plants were assayed for oviposition stimulants and deterrents. Larval survivorships on these plants were also compared as an estimate of fitness. In contrast to C. unshiu, for which both females and larvae of P. protenor and P. xuthus are successfully adapted, O. japonica was completely rejected by ovipositing females and larvae of both species. P. protenor readily accepted F. ailanthoides, but persistently avoided P. amurense for egg-laying despite its high suitability for larval growth. Unlike P. protenor, P. xuthus females only marginally accepted F. ailanthoides and P amurense were found to contain both oviposition stimulatory and inhibitory substance(s) for the two species. On the other hand, negative ovipositional responses of both species to O. japonica proved to be attributable to multiple deterrents in this plant. We conclude that differential acceptance of 4 plants by the two Papilio females can be attributed to the responsiveness of the respective species to stimulants and deterrents coexisting in the plants.
