Scientists have known for a while that parasites can induce "behavioral modification" in its hosts - but this one is new: a parasite that turns its host into a bodyguard!
Inside the caterpillar host, a cruel drama takes place: the eggs of the parasitoid hatch and the larvae feed on the body fluids of the host. The caterpillar continues feeding, moving and growing like its unparasitized brothers and sisters. When the parasitoid larvae are full-grown, they emerge together through the host's skin, and start pupating nearby. Unlike many other combinations of host and parasitoid, the host remains alive but displays spectacular changes in its behaviour: it stops feeding and remains close to the parasitoid pupae. Moreover, it defends the parasitoid pupae against approaching predators with violent head-swings.
(Photo: José Lino-Neto; Grosman et al. )