Wasps enslave caterpillars. It could be seen as a genetics accident, though it appears to be a conscious decision by Someone out there. The wasps could not survive without caterpillars. If caterpillars all died out so would wasps.
Parsitic wasps lay their eggs in all types of lepidoptera caterpillars. Both insects are so close in evolutionary terms that some wasp genes are actually in caterpillars. The reason for this is that 300 million years ago there was a common ancestor of Hymenopter, the insect order to which wasps belong, and Lepidoptera caterpillars.
When eggs are laid inside the caterpillars, a large bracovirus is injected which supresses the immune response of Lipidoptera, so grubs are not killed off. They hatch and eat caterpillars alive! Sometimes caterpillars survive and develop into buterflies and moths with bracovirus DNA because it was picked up from wasps before injection into caterpillars.
◆ Genetics by Ty Buchanan ◆