Insane in the brain: How neuroparasites manipulate the insect’s brain function and behaviour

Summary

Neuroparasites are parasites that modify the behaviour of their host and are expected to do so due to their infection of the hosts’ central nervous system (CNS). Two study systems were included in this dissertation, with the focus on the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in the beet armyworm (Spodoptera exigua). A second line of research concerned another well-known CNS-infecting parasite; the lancet liver fluke (Dicrocoelium dendriticum) in the forest ant host (Formica polyctena). Results from this dissertation enlighten different aspects of the biology of neuroparasites and advances what is known in the field. Results cover the location of nerve signalling molecules in the CNS of uninfected hosts, the location of parasites in the infected CNS and the overlap or lack thereof with nerve signalling molecules. Furthermore, the thesis describes the role of a specific viral protein in virus entry into the CNS, the mechanisms behind the behavioural alterations, and abiotic factors in the field that influence the expression of parasite-induced behaviour.