Behavior of Hawkmoths on Flowers of Datura meteloides

Datura meteloides is pollinated mainly by long-tongued hawkmoths: Manduca quinquemaculata, M. sexta, and Hyles lineata. The most abundant and important of these species in the Arizona and New Mexico populations studied is M. quinquemaculata. There is good correspondence between the proboscis length of M. quinquemaculata (10 ± 1.2 cm) and corolla tube length of D. meteloides (10.5-11.0 cm) The Manduca moths feeding on D. meteloides flowers in the Arizona populations behaved in an intoxicated manner All parts of this plant, including the flowers, are known to contain tropane alkaloids, and such alkaloids may well occur in the nectar also. Intoxicating substances in nectar or other floral tissues could represent a new or little known type of floral reward to look for in other plant groups