Regulation of Insect Development

Insect postembryonic development, including molting, metamorphosis, body size control, and diapause, is hormonally regulated by the brain, prothoracic glands (PGs), and corpora allata (CA). The PGs and CA produce ecdysteroids and juvenile hormone, respectively, both of which are direct regulators of insect development. The brain secretes prothoracicotropic hormone (PTTH), the main regulator of PG activity. Hormone secretory activity of CA and PGs is positively and negatively regulated by a variety of peptide hormones and neuropeptides. This chapter reviews their effects on these endocrine organs and discusses the physiological significance of their actions in regulating insect development.