Tobacco Budworm: Effect of Larval Feeding on Presquaring Cotton

Three cultivars of cotton Gossypium hirsutum (L.) at four presquare stages of plant growth were caged in the greenhouse and infested with one 3rd-instar larva of the tobacco budworm, Heliothis virescens (F.), per plant per 72 h. Larval feeding damaged terminal buds in 70% of the infested plants. In addition, such feeding caused swollen nodes, shortened internodes, damaged leaves, and excessive branching of the main stems; these symptoms are very similar to those described for the “crazy cotton” phenomenon.