Novel, Non-Solanaceous Hostplant Record for Manduca sexta (Lepidoptera: Sphingidae) in the Southwestern United States

Abstract
Field observations in the Tucson, AZ, basin reveal that Manduca sexta (L.) has been incorrectly described in the past as a specialist herbivore that oviposits and feeds exclusively on plants in the family Solanaceae. We present evidence that previously unreported, non–solanaceous hostplants are routinely used by M. sexta females for oviposition. These plants permit successful larval development, through to emergence of the next generation of adults. The novel hostplants, 2 species of the genus Proboscidea, belong to the Martyniaceae, a family taxonomically distant from the Solanaceae. Our observations on oviposition and larval feeding were conducted during 2 consecutive field seasons. During the 2nd field season, we counted M. sexta eggs on native hostplants, both solanaceous (Datura wrightii, Regel) and non–solanaceous (2 Proboscidea species), and found higher abundance of eggs on the Proboscidea spp., in approximately a 3:1 ratio. Our results challenge the commonly held view that M. sexta is a specialist exclusively on solanaceous plants.