The effect of disease on the migration of the fall armyworm, Spodoptera frugiperda

Animal migration and disease are closely linked, yet we know relatively little about interactions between the two. One area where this relationship is particularly relevant is insect crop pests and their pathogens, some of which have the potential to be used as microbial biopesticides. Using the noctuid moth pest Spodoptera fruigpera and its baculovirus S. frugiperda multiple nucleopolyhedrosis virus (SfMNPV) as a model system, we consider the effects of viral infection on flight behavior. This question is addressed in the laboratory using tethered flight mills to measure migratory flight activity in moths with varying levels of sub-lethal viral infection. Work to date has yielded interesting insights in the variability within this system, helping us to understand the effect of complex underlying factors such as larval rearing density, sex, generational and family effects. In particular we report some of the first findings of sexual differences in the effect of disease on flight in a migratory host.