Insect host-parasite interrelations involve co-adaptations of consider
able complexity. Against endoparasites, immune competent insect hosts
initiate a hemocyte-mediated response that quickly destroys the intrud
ers and envelops them in multilayered, melanotic capsules. In this rev
iew, Yves Carton and Anthony Nappi focus on recent studies of the cyto
logical, biochemical and genetic mechanisms involved in the cellular i
mmune response of Drosophila against wasp parasitoids.