parasitic

This is the seventh of eight posts on evolutionary research to celebrate Darwin's bicentennial. It combines many of my favourite topics - symbiosis, horizontal gene transfer, parasitic wasps and viruses. Parasitic wasps make a living by snatching the bodies of other insects and using them as living incubators for their grubs. Some species target caterpillars, and subdue them with a biological weapon. They inject the victim with "virus-like particles" called polydnaviruses (PDVs), which weaken its immune system and leave the wasp grub to develop unopposed. Without the infection, the wasp egg…