Pollen carried for long periods by butterflies

The study of insect pollination, and of pollinator efficiency, has long been based on observation of insects visitors to plants. This approach stems from the assumption that the number of visits made by insects, enticed by nectar or other means, is directly related to the amount of pollen carried and transferred (Proctor and Yeo 1973 ). In relatively few studies has the amount of pollen carried by pollinators been successfully quantified (Mikkola 1971, Levin and Berube 1972, Cruden and Hermann-Parker 1979). In a recent investigation using light microscopy Wiklund et al. (1979) demonstrated that butterflies of the species Leptidea sinapis bore few pollen grains despite extensive foraging from violets and other flowers. This was attributed to a form of nectar-theft by the butterfly, where the proboscis \u27robbed\u27 the plant of nectar without contacting the anthers; that is, the normal pollination mechanism of the flower was avoided. On the basis of their study, Wiklund et al. proposed that the Lepidopteran proboscis has evolved primarily for the purpose of such robbery. We describe here results from other species of butterfly indicating that pollen is carried by Lepidopteran mouthparts, and hence that many butterflies may be good pollinators and not nectar thieves. Additionally we demonstrate that butterflies may have an unsuspected role to play in long-distance pollination