The Specificity of the Tobacco Hornworm, Protoparce Sexta, to Solanaceous Plants1

Oviposition and feeding of the tobacco hornworm arc almost entirely restricted to plants of the family Solinaceae. Oviposition appears to be initiated by olfactory stimuli widely distributed in this plant family, and consequently it, is largely suppressed in the absence of host plants or after excision of the antennae. Both in the field and laboratory, the moths preferred tomato foliage over other solanaceous plants for oviposition. Larval feeding appears to be governed by gustatory stimuli common to plants of this family. On certain ones, such as Nicandra and Petunia , feeding and growth are limited by the presence of repellents or toxins. Some limited feeding occurred on certain nonsolanaceous plants after various periods of starvation.