Growth and Infestation of Bollworms and Other Insects on Glanded and Glandless Strains of Cotton1

Abstract

Laboratory and field rests with experimental cotton lines showed that larval growth of the bollworm, Heliothis zea (Boddie), and the tobacco budworm, H. virescens (F.), was related to content of gossypol in the host plant supplied through pigment glands. Larval growth was greater on glandless than on glanded cotton strains, the glandless plants were highly attractive to several other insects which are not pests of glanded commercial varieties, an indication that commercial use of glandless varieties might introduce new insect-control problems. Results of the studies suggest that it may be possible to increase the resistance of cotton to insects by breeding for a higher gossypol content.