ABOVE: The cotton bollworm (H. armigera) is one of the species discovered to have parasitoid killing factor genes.
© ISTOCK.COM, TOMASZ KLEJDYSZ
tI’s a scene straight out of your worst nightmare: dozens of tiny, milky larvae wriggle out of their still-living caterpillar host, leaving behind the scarred, gaping holes from whence they emerged. The larvae belong to a type of wasp called parasitoids, whose young dine on the flesh of hosts their parents pick out for them.
But research published Thursday (July 29) in Science suggests that not all caterpillars infected with parasitoid wasps will meet the same grisly end. The study identified a new family of proteins—parasitoid killing factors (PKFs)—that kill parasitoid larvae. PKF genes were found in several large double-stranded DNA viruses that infect lepidopteran insects (moths and butterflies), but also within the genomes of several Lepidoptera species themselves, suggesting that the genes have been swapped between viruses and ...
