Caught red handed: Parasitoid eggs absorb host lipids

Parasitoids are insects that have a unique life history strategy. They lay their eggs on or in a host arthropod, and their offspring consume the host to acquire all of the energy/nutrients they need to emerge as adults. Many parasitoids eat very little as adults and thus have limited energy stores to provision the next generation of eggs with yolk. However, their eggs dramatically increase in size once they are laid inside the host, presumably by absorbing host nutrients via an unknown mechanism. The fruit fly Drosophila melanogaster is a genetic model organism that is naturally infested by a variety of parasitoid wasp species. By feeding flies fluorescent lipids, I found that parasitoid eggs from four different genera rapidly acquire host lipid stores. Using the genetic tools available in Drosophila, I am investigating the underlying mechanism by which this happens and whether I can genetically manipulate fly lipid physiology to control the outcome of fly-parasitoid interactions.