The Comparative Preference of Insects for Glanded and Glandless Cottons1

Abstract

In field studies damage caused by Heliothis zea (Boddie) was the same for Rex Smooth leaf glanded and glandless cotton lines and glanded Deltapine Smooth Leaf. However, its damage was greater on glandless Acala than on glanded Acala cottons. Adult Maecolaspis flavida (Say) and Gastrophysa cyanea (Melsheimer), which normally do not damage glanded cotton, showed a marked feeding preference for all glandless lines. Alabama argillacea (Hübner) moths preferred to oviposit on glandless lines. Resulting larval feeding caused considerably more damage to all glandless than to glanded lines. Whether the insect preferences were a result of the glandless trait alone, or of other traits controlled by a gene or genes closely linked to the glandless genes was not determined. The data, particularly that relating to chrysomelids, indicated some of the potential insect problems associated with a desirable agronomical change in the biochemistry of the cotton plant.