Genotype co-occlusion technology: a novel paradigm for the development of improved alphabaculovirus-based insecticides

Abstract

Insect pathologists have long recognized that insect pathogenic viruses have evolved to be effective pathogens, and not necessarily effective insecticides. Molecular techniques have begun to reveal the presence of genetic heterogeneity in populations of entomo-pathogenic viruses, particularly in the case of baculoviruses. We have exploited this diver-sity to develop a novel technology involving isolate dissection, genotype interaction anal- yses and assembly of novel genotype mixtures to create unique non-natural combinations of component genotypes with insecticidal characteristics that are better than those of the natural virus populations. The production of mixed genotype occlusion bodies (co-occlusion) and mixed genotype virions (co-envelopment) is an integral part of this technology, that has recently been patented by us and acquired by a multinational agrochemical company. We present the value of this technology for development of non-recombinant virus insecticides, with better-that-wild-type characteristics, based on unique combinations of genotypes. To illustrate this we present examples of SeMNPV, SfMNPV, ChchSNPV, HearSN-PV and HearMNPV based insecticides that have been improved in this way. This represents a new paradigm in the development of effective virus-based insecticides which incidentally appears to challenge a number of the established models of baculovirus replication and host range.