五、ChitinSynthesisInhibitors（CSIs)>CSls，suchashexaflumuron（氟铃脲），lufenuron（虱螨脲）anddiflubenzuron（灭幼脲），inhibittheproductionofchitin,amajor component ofthe insect exoskeleton. Insects treated withCSls become unabletosynthesize new cuticle,and thereforeunabletosuccessfullymoltintothenext stageCSlsmaybetoxictootherarthropods,andIGRmetabolitesmayhave adverse effects on vertebratesdueto theirabilitytobind to certain members of thenuclearhormone receptor family➢CSIs, such as hexaflumuron（氟铃脲）, lufenuron（虱螨脲） and diflubenzuron（灭幼脲）, inhibit the production of chitin, a major component of the insect exoskeleton. Insects treated with CSIs become unable to synthesize new cuticle, and therefore unable to successfully molt into the next stage. ➢CSIs may be toxic to other arthropods, and IGR metabolites may have adverse effects on vertebrates due to their ability to bind to certain members of the nuclear hormone receptor family. 五、 Chitin Synthesis Inhibitors (CSIs)