Parasites can induce dramatic changes of behaviour in their host species. This behaviour is thought to be detrimental to the host, but beneficial to the parasite. In a joint publication, researchers from the University of Amsterdam and University of Viçosa ( Brazil ) show evidence of spectacular behavioural changes induced by a parasitic wasp in the caterpillar of a moth species.

After the wasp (Glyptapanteles sp.) has oviposited eggs in the body of a caterpillar (Thyrinteina leucocerae), these develop into larvae that live on the body fluids of the caterpillar. After the wasp larvae crawl out of the caterpillar to pupate, the caterpillar acts as a bodyguard to defend them from predator attacks. This results in a twofold reduction of predation of the wasp pupae in the field.

After several days, the adult wasps emerge from their pupae and the caterpillar dies.

(photo Jose Lino Neto)

See publication in PLoS One
Movie of a caterpillar defending parasitoid pupae
Movie of an unparasitized caterpillar showing no response to a predator