The Orchestrated Manipulation of the Host by Chelonus Inanitus and its Polydnavirus

Publisher Summary This chapter reveals physiological, biochemical, ultrastructural, and molecular methods, and this broad approach clearly shows that the interactions of the Chelonus inanitus bracovirus (CiBV) venom and the parasitoid larva are multifaceted and change in the course of parasitoid and host development. The interactions of the Chelonus inanitus bracovirus (CiBV) and the parasitoid larva with the host are complex and variable and venom is essential only in the initial phase of parasitization. C. inanitus is an egg–larval parasitoid and in the beginning it is a conformer and hardly influences the host. But towards the end of its first larval instar, when the host is a fourth-instar larva, CiBV and the parasitoid larva begin to manipulate the host at various levels in an orchestrated manner. CiBV plays piano pianissimo as only low amounts of viral transcripts and only very few virus-related proteins of low abundance are found in the host. Expression of viral genes varies along with host and parasitoid development. Nevertheless, the effects of CiBV are strong: the virus prevents encapsulation of the parasitoid larva, alters the host's nutritional physiology, and induces a developmental arrest in the prepupal stage by acting on the host's ecdysone production.