Cotton-Plant Pigments as a Source of Resistance to the Bollworm and Tobacco Budworm12

Abstract

Three pigments of the cotton plant Gossypium hirsutum were incoporated in the artificial diet of larvae of the bollworm, Heliothis zea (Boddie), and the tobacco budworm, Heliothis virescens (F.), to determine their effects on development. Gossypol was equally toxic to the bollworm and the tobacco budworm. Less than 30% of the larvae of both species reached the pupal stage when the diet contained 0.2% gossypol. Quercetin inhibited the growth of bollworm larvae, but there was relatively little mortality at concentrations below 0.8%. However, this chemical killed more than 70% of budworm larvae at the 0.1% concentration. Rutin was found to be less toxic to both species than gossypol or quercetin. However, it was more toxic at the higher dosages to the budworm than to the bollworm. The feasibility of increasing the gossypol and quercetin content in the cotton plant is discussed.