Insects are a major group of arthropods and the most diverse group of animals on the earth, with over a million described species. In common with all other life forms, insects suffer from viruses that cripple and kill. Admittedly, insects transmit viruses that cause illness in humans, but the insect in such cases is usually unaffected. This book includes research on such viruses affecting humans. Also included in this book are the ways to recognize insect viruses and their use in pest control. Basic and applied research on insect virus proteins associated with the peroral infectivity is reviewed as well. Furthermore, RNAi has been applied to a number of studies involved in insect immunity. Thus, the effect of RNA interference on viral infections is also studied.