Feeding Preferences and Utilization Studies as Tools in Developing an Optimum Diet for Heliothis zea (Lepidoptera: Noctuidae)1

Feeding tests with combinations of casein, cottonseed flour (CSF), soybean protein, and wheat germ were used to determine the preference of Heliothis zea (Boddie) for diets with either casein or CSF added to a protein mixture of 6%soybean protein/wheat germ (1:1). Of four diets with added casein or one of three types of CSF, the casein diet was least preferred in choice tests. Utilization tests showed that the diet containing casein was best utilized, followed closely by the most preferred CSF diet. Protein scores of the diets relative to a carcass analysis standard showed the casein diet to have the best balance of amino acids. CSF diets were lower in lysine than the casein diet.