Hawkmoth pollination of Mirabilis longiflora (Nyctaginaceae).

A guild composed of very-long-tubed hawkmoth flowers (nectar tubes, 9 cm or more long), belonging to different genera and families, occurs in the American Southwest. Our knowledge of the hawkmoth associates of these flowers is fragmentary. Mirabilis longiflora, a member of the guild with a tube 10.0-10.5 cm long, was found to be visited and pollinated mainly by Manduca quinquemaculata with a proboscis 10.7-11.6 cm long in the Chiricahua Mountains of southeastern Arizona. This example fits in with four other previously reported cases. The long-tongued Man. quinquemaculata is now known to be associated with five species of very long-tongued hawkmoth flowers in the Southwest, and Man. rustica has been found on one of them.