Interpopulation differences in host preference and the evolution of learning in the butterfly, Battus philenor.

Host-discrimination behaviour of adult female pipevine swallowtail butterfly was investigated for an E Texas population that uses 2 host species with different leaf shapes and a Virginia montane population that uses 1 host species with a single leaf shape. While Texas and Virginia females exhibited similar chemotactile responses after landing on various host species, butterflies from each population landed more frequently on certain host species used by that particular population. Despite this difference in searching behaviour, Texas and Virginia populations were equally capable of learning to search for the leaf shape of a particular host species in artificial enclosure arrays. Selection for restriction of learning of leaf-shape preference in the Virginia montane population may be constrained by selection for learning of other types of discrimination behaviour.-from Author