Trehalose is a non-reducing disaccharide comprising of two glucose molecules.It was found in various organisms,including bacteria,fungi,plants and insects.As the main component in insect haemolymph,trehalose was synthesized by trehalsoe-6-phosphate synthase and trehalose phosphatase.To utilize trehalose,it must be hydrolyzed by trehalase for glycolysis.The trehalose synthesis in fat body was under the control of hormone and the main component of trehalose in haemolymph was glycogen.The trehalase in insects was well studied,but the mechanism by which its activity was controlled was still not clear.