Mythimna Separata is major agricultural pests that cause significant yield losses of crop plants each year.Expression of double-stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant-mediated RNA interference (RNAi).Thus, as a potential effective strategy for insect pest management in agricultural practice, RNAi for Mythimna separata control has received close attention in recent years.We propose here to develop Mythimna separata-resistant plants using RNAi technology.Our primary hypothesis is that if we can identify and deliver to Mythimna separata interfering RNAs that down-regulate expression of Mythimna separata genes such as Chitinase genes which are essential for their growth and development, they will result in a debilitating phenotype.To do this, we designed and carried out the following experiments.We used different sources of RNAi effectors to achieve knockdown of Mse-Chi genes and caused lethal effects.Transgenic rice expressing the hairpin dsRNAs was verified by southern blot and RT-PCR.When the transgenic rice was fed to Mythimna separata, target Chitinase genes transcript levels were substantially decreased, also resulting in retarded larval growth and increased mortality.