“…Insect growth regulators (IGRs) are considered as an ideal class of insecticides that can disrupt or interfere with the normal growth and development of insects by targeting specific proteins associated with molting or metamorphosis. − Compared with conventional insecticides, IGRs possess the characteristics of higher efficiency, lower toxicity, better selectivity, less incidence of resistance, and safer to the environment and nontarget organisms, thus enabling them to meet the requirements of integrated pest management (IPM) in crop protection. , It has been reported that ecdysone receptor (EcR) and Of ChtI, Of ChtII, and Of Chi-h are involved in the insect molting. ,, In the process of insect development, 20-hydroxyecdysone (20E), the active form of ecdysteroid, is first bound to the ecdysone receptor (EcR)-ultraspiracle protein (USP) and subsequently initiates the upregulation of myriad genes related to the regulation of molting, of which three critical chitinolytic enzymes Of ChtI, Of ChtII, and Of Chi-h synergistically participate in the degradation of cuticle chitin in insect molting after being significantly induced by 20E, and interfering with the activity of any one of these chitinases can lead to the abnormal molting and death in insects. , Of ChtI and Of ChtII are endochitinases that can split randomly the β-1,4 glycosyl linkages at the internal sites of chitin, whereas Of Chi-h is an exochitinase requiring from the nonreducing end in chitin to split the β-1,4 glycosyl linkage. , The transcriptional and protein expression patterns indicated that Of ChtII was produced earlier than Of ChtI and Of Chi-h during larva–pupa molting, which could loosen compacted chitin particles for further degradation by Of ChtI and Of Chi-h . Therefore, EcR and three chitinases Of ChtI, Of ChtII, and Of Chi-h are considered as potential targets for the design of highly efficient and low-toxicity IGRs due to their properties being systematically involved in disturbing the insect molting and exfoliation. − …”