This book provides a comprehensive view of the insect neuroendocrine system, incorporating recent advances in bioinformatics, comparative genomics, and molecular genetic approaches.Part I traces the history of the development of insect peptide hormone research and offers an overview of insect peptide hormones and neuropeptides. Special attention is given to their relatedness to vertebrate counterparts and to the structural features of the insect neuroendocrine system, providing readers with an overall picture of insect neuroendocrinology. Part II illustrates the diverse functions of peptide hormones and neuropeptides in insects, including a brief history of the study of each hormone and recent advances in each area of study. A unique feature of this book as a textbook of insect endocrinology is its comparison of peptide hormones and neuropeptides between insects and other animals from a molecular phylogenetic perspective. New additions include the distribution of endocrine/neuroendocrine cells and peptidergic neurons that produce each neuropeptide within the insect body, as well as the distribution of each neuropeptide gene among the genomes of representative insect groups. As these topics have emerged over the past decade, this book offers readers their first opportunity to learn about them.This book is intended primarily for researchers and graduate students in insect science, especially endocrinology and physiology. It may also interest researchers working on the endocrinology of non-insect animals, including vertebrates. General readers and undergraduate students interested in this topic may also find it accessible and informative.