Chitinases play important roles in degrading chitin in development, molting andperitrophic membrane of Locusta migratoria and the Chitinase 5 of the L.migratoria is encoded by two genes,LmCht5-1 and LmCht5-2.The dsRNA of LmCht5-linjection in 5th nymph ofL.migratoria led to severe molting defects and lethality, while no obvious effects were detected with RNAi of LmCht5-2.Although the two Cht5 genes have the complementary expression pattern through the egg development, the functional differentiation of LmCht5-1 and LmCht5-2 in whole development remains not to be elucidated.