Virus-Induced Behavioural Changes in Insects

Increasing evidence shows that host behaviour often changes following infection by a variety of parasites, including viruses. The altered behaviour is either induced by the parasites to enhance parasite survival and transmission, or is a response of the host to avoid spread of infection in the host population. Given the high prevalence of viruses among insects, in a virus-host interaction or in a virus-vector relationship, viruses might have a huge impact on insect behaviour. This review first describes known examples of changes in insect behaviour upon virus infection. Although scarce, any known information on the underlying mechanism is also included. Special attention is given to baculoviruses and the hyperactivity and tree-top disease that they induce in their caterpillar hosts, so far the best studied systems in this research field. Subsequently, we discuss the virus-induced changes in insect behaviour from an ecological and evolutionary point of view