Pesticides: Insecticides and Fungicides Are Chitin Synthesis Inhibitors

Several important groups of fungicides and insecticides are specific inhibitors of chitin synthesis in a Phycomyces enzyme system and in insect organ cultures. The recently discovered benzoylphenylurea insecticides, which prevent chitin synthesis in insect tissues, are apparently not direct-acting chitin synthetase inhibitors. These insecticides may prevent insect chitin synthesis by interfering with the proteolytic activation of the chitin synthetase zymogen.