Project title: Get by with help from your little friends: Understanding defensive symbiont dynamics in the real world
Summary: Virtually all insects are attacked by a multitude of natural enemies, and therefore undergo strong selective pressures to defend themselves. Recent evidence suggests that rather than evolving resistance through the host genome, insects may recruit symbiotic bacteria to help defend against would-be attackers. Studies on the symbionts of insects have found they can protect against attack by nematodes, pathogenic fungi and parasitoid wasps. In this project, we aim to investigate the pattern of infection by defensive symbionts among aphid species using a combination of molecular biology, ecological experiments and genomics, and ask the extent to which this pattern is shaped by the selective pressures exerted by parasitoids or other forces such as genetic incompatibilities between the symbiont and its host.