Gall insects are everywhere: It is estimated that 1,000 species of gall wasps in North America are responsible for the galls on oaks alone.

“Each gall wasp is attacked by between 10 and 25 different species of parasites.”

Then, puncturing the gall, it injects its eggs, beside or inside the young oak gall wasp.

After feeding on the gall wasp’s body from the inside, the crypt-keeper wasp burrows out of the hosts' head.

To find out how many hosts this “hypermanipulator” has, researchers collected more than 23,000 galls containing more than 100 species of oak gall wasps—and some crypt keepers.