Viruses that are pathogenic to beneficial insects and other arthropods cause millions of dollars of damage every year to industries, such as sericulture, apiculture, and aquaculture (e.g. infecting honeybees and silk worms). On the other hand, viruses that are pathogenic to insect pests can be exploited as attractive biological control agents. Another fascinating feature of these viruses is that some, e.g. baculoviruses, have been commercially exploited for use as gene expression and delivery vectors in both insect and mammalian cells. All of these factors have led to an explosion in the amount of research into insect viruses in recent years, generating impressive quantities of information on the molecular and cellular biology of these viruses. This timely book reviews the exciting new developments in the field of insect virology. Written by internationally renowned insect virologists, the chapters review the current molecular biology of all the major groups of insect pathogenic viruses and suggest future directions for research. The book is divided into three parts: 1) DNA viruses, 2) RNA viruses, and 3) current hot-topics in insect virology. The virus groups covered include: Ascoviruses, Baculoviruses, Densoviruses, Entomopoxviruses, Hytrosaviruses, Iridoviruses, Nudiviruses, Polydnaviruses, Dicistroviruses, Iflaviruses, Nodaviruses, Tetraviruses, and Cypoviruses. Special topic chapters review exciting recent developments in insect virology including RNAi, insect antiviral responses, structural comparison of insect RNA viruses, and viral ecology. The book is essential reading for every insect virologist in both the academic and private sectors. It is also strongly recommended for other virologists, particularly those interested in virus evolution, virus structure, viral vectors, biological control of insects, and insect immunity.