Abstract
Nutritional and behavioral assays were designed to study the effect of dietary carbohydrates on the Angoumois grain moth, Sitotroga cerealella (Oliv.). Nutritional results showed that larvae grew better in artificial pellets containing cornstarch (60%, w/w) than rice or potato starch. Dietary amylopectin and glycogen supported development while larvae did not grow in diets containing amylose, cellulose, or inulin as the sole test carbohydrate. Whole or partial replacement of dietary cornstarch with mono- and disaccharides resulted in poor growth because of the inferior physical consistency of the test pellets. Behavioral results showed that the growth suppression caused by dietary amylose could be attributed to an inability to digest amylose rather than to any feeding deterrency. It was concluded that the insect has a specific dietary requirement for a branched-chain polymer of glucose with α (1 → 4) and α (1 → 6) linkages. The nature of insect digestive amylases is briefly discussed.