The Effect of Selected Protease Inhibitors and Lectins in Artificial Diet on Survival and Growth of Eldana Saccharina Larvae

Protease inhibitors, which can inhibit insect digestive enzymes, and carbohydrate binding lectins are potential control mechanisms against herbivorous insects. Larval midgut extracts fi-om Eldana saccharina Walker (Lepidoptera: Pyralidae) were assayed for protease activity in the presence of protease inhibitors in order to determine the dominant protease types (serine, aspartic, metalloor cysteine). Through the use of protease inhibitors, serine proteases having activity similar to mammalian chymotrypsin/elastase were implicated as dominant. Protease inhibitors of this dominant activity were effective only in combination with lectins. Inhibitors of other protease classes were not effective. The selection and genetic engineering of suitable protease inhibitor and lectin genes into sugarcane are discussed. agglutinin (WGA) and selected protease inhibitors on larval survival and growth of the sugarcane borer Eldana sacchar i n ~ Walker (Lepidoptera: Pyralidae).