Advances in Insect Virology

Publisher Summary This chapter describes the current advances that have been made in a number of aspects of insect virology in the past few years. The baculoviruses feature most dominantly, because it is this group of insect viruses that forms the focus of attention for the majority of insect virologists and molecular biologists. However, a number of recent advances have been made in the understanding of the replication of other insect viruses, notably the entomopoxviruses (EPVs). The chapter also describes advances in the use of baculoviruses, as expression vectors of foreign genes, in the development of genetically modified insecticides, vertical transmission, and different aspects of interactions with host cells, including the phenomenon of apoptosis. Poxviruses in insects were originally described by Vago (1963) and since then EPVs have been isolated from over 60 different insect species in widespread geographical locations. EPVs have been found in all four economically important insect orders, Lepidoptera, Coleoptera, Diptera, and Orthoptera. The Iridoviridae are a group of large, icosahedral dsDNA viruses that replicate in the cytoplasmic compartment of infected cells. The chapter also discusses the RNA viruses of insects. The family of insect viruses comprises seven members that have all been isolated from the pest species of Lepidoptera. All members replicate exclusively in insect hosts. Very little is known about the replication cycle or genetic organization of this group of viruses, mainly due to the lack of suitable cell culture systems capable of supporting virus replication.