Hormonal regulation of development and reproduction

The two major insect hormones ecdysterioids (the most active form is the 20-hydroxyecdysone, 20E), sequiterpenoids (juvenile hormones, JH) regulate almost every aspect of insect life including embryogenesis, molting, metamorphosis and reproduction. The physiological and biological processes regulated by these hormones have been studied over the last century and well documented in several reviews. After the advent of genomic technologies, the molecular processes that are regulated by these hormones and the genes targeted by receptors and transcription factors that transduce signals of these hormones are being actively investigated. With the sequencing of genomes and transcriptomes of many pest insects, we began to identify key players involved in action of these hormones in pest insects. Insulin-like peptides have been identified in Drosophila melanogaster and shown to play key roles in regulation of growth, development of nervous system, reproduction and lifespan. Recently, insulin-like peptides have been identified in several insect pests and disease vectors and shown to play key roles in regulation of growth, development and reproduction. In this review, I will focus on the hormonal regulation of embryogenesis, metamorphosis and reproduction. I shall focus on systems and physiological processes that are amenable for development of methods including double-stranded RNA or small molecules to interfere with these processes with a goal to develop novel pest and disease vector control strategies.