Pollination of the long-spurred African terrestrial orchid Bonatea steudneri by long-tongued hawkmoths, notably Xanthopan morganii

Charles Darwin correctly predicted the existence of an extraordinarily long-tongued hawkmoth in Madagascar, based on the length of the floral spur of an Angraecum orchid. This hawkmoth, Xanthopan morganii, is also the longest-tongued hawkmoth on the African mainland, but its ecological role as a pollinator has been virtually unknown outside of Madagascar. We investigated whether X. morganii pollinates Bonatea steudneri, an orchid with floral...