A Parasite that Induces Love in its Host

I love it when weird science just screams science fiction. IO9 has a story of a truly odd host/parasite life cycle. One where the parasite induces the host to protect the parasite above all else. A Brazilian wasp has evolved a very peculiar way to reproduce - in which it changes the host's behavior to the point where that after emerging from the host's body, the host will continue to protect the wasp pupa, forgoing all other functions, like eating! Upon emerging the caterpillar host covers the pupa with silk and then stands guard until they emerge as adult wasp. In fact the caterpillar refuses to eat or leave until the wasps hatch. The caterpillar dies soon after the adults emerge from their pupae, so there can be no benefit whatsoever for the caterpillars.

complete PLoS ONE article