Insect hormones

Abstract

Recent estimates place the number of insect species at 2-20 million, more by far than the total of all other animals and plants on Earth. Although insects affect the human condition in a variety of ways, primarily as pollinators, competitors for agricultural products, and vectors of disease, their sheer diversity and numbers make this class of arthropods worthy of study. Indeed, insects have become the model of choice for a variety of research endeavors in genetics, biochemistry, developmental biology, endocrinology, and so forth. Because they are encased in a semirigid exoskeleton (cuticle), insects and other arthropods must shed this cuticle periodically (molt) in order to grow and undergo metamorphosis. Although insect molting and metamorphosis have been scrutinized since the time of Aristotle, the exact control mechanisms have remained elusive. However, research on insect hormones has contributed significantly to the general field of endocrinology. © 2005 Humana Press Inc.