The aim of this project is to.assess the efficacy of three new classes of hydrolase genes that might have insecticidal activity when introduced into transgenic cotton. These genes encode hydrolytic enzymes including lipases; phospholipases and phosphatases. Feeding studies on Heliothis armigera larvae indicate that crude preparations of these hydrolytic enzymes significantly retard the growth of these insects on a synthetic diet and may lead to larval death. More refined studies on purified proteins and isolated genes will be required to demonstrate the usefulness of these gens in insect control