Future insecticides targeting genes involved in the regulation of molting and metamorphosis

Because of their rigid exoskeleton, insects need to undergo periodic molts during which they shed their old cuticle and produce a new one to accommodate further growth. A number of hormones play critical roles in the initiation and coordination of the processes of molting and metamorphosis. Studies on several model insects such as Bombyx mori, Hyalophora cecropia, Manduca sexta and Drosophila melanogaster, have led to the identification of key hormones and the elucidation of their roles in molting and metamorphosis. Best known for their roles in these two processes are the steroid hormone ecdysone1 and the sesquiterpenoid, juvenile hormone (JH). However, these developmental events also involve a number of relevant peptide hormones, including prothoracicotropic hormone (PTTH), eclosion hormone (EH), pre-ecdysis triggering hormone (PETH), ecdysis triggering hormone (ETH), crustacean cardioactive peptide (CCAP) and bursicon (BU).