Strepsiptera

Strepsiptera is an order of insects with eleven living families and about 600 described species, all of them parasites that develop inside other insects such as bees, wasps, leafhoppers, silverfish and cockroaches. Most females remain inside their host for life, while newly hatched larvae leave to find a new host and males emerge briefly as adults to seek mates; the order is thought to share a common ancestor with beetles roughly 300 to 350 million years ago, though its oldest fossils date only to the mid Cretaceous.