Thus Bt transgenic rice has much appeal for controlling the stem borer. Codon optimized Bt genes have been introduced into rice and show excellent levels of resistance in the laboratory and greenhouse (Datta et al 1997). Bt rices have also been tested under field conditions in China and have excellent resistance to diverse populations of yellow stem borer. Besides Bt genes, other genes for insect resistance such as those for proteinase inhibitors, α-amylase inhibitors and lectins are also beginning to receive attention. Insects use diverse proteolytic or hydrolytic enzymes in their digestive gut for the digestion of food proteins and other food components. Plant derived proteinase inhibitors or α-amylase inhibitors are of particular interest because these inhibitors are a part of the natural plant defense system against insect predation. Xu el al (1996) reported tansgenic rice carrying cowpea trypsin inhibitor (Cpti) gene with enhanced resistance against striped stem borer and pink stem borer.