TIL: This Wasp Turns Prey Into Zombies

If you see a cockroach scurry through your kitchen, your first reaction might be: “Arghh! A cockroach! Quick! Squish it with John Grisham!” But wait! You don’t need to sully your favorite legal caper. Instead, fetch a jewel wasp to do your bidding. These brutal parasites rob a cockroach of its free will before inflicting a slow and horrific death.

The attack begins with a quick sting to the cockroach’s body, temporarily paralyzing its front legs. Next, the jewel wasp uses its stinger to stab the roach in the head, feeling around for a specific part of the ill-fated insect’s brain. The venom the wasp injects blocks the roach’s octopamine receptors, stealing its ability to make independent decisions.

All this stinging makes our roach assassin famished, so she rips off the palmetto bug’s antennae and enjoys a drink of blood. The rejuvenated wasp then guides the zombified roach back to its burrow, where she lays an egg on her new playmate.

In about three days the newly hatched larva will chew its way into the still very much alive cockroach’s abdomen, where it will feed on the roach’s organs. Shrewdly saving the nervous system for last, the wasp baby ensures its babysitter-turned-breakfast stays alive and juicy for as long as possible. Feeling sick to your stomach yet?

Now that the baby parasite has provided the most miserable death imaginable, it will haunt the roach’s carcass until fully mature, when it will spring forth in search of another cockroach friend. Yikes! On second thought, stomp on that roach; you’re probably doing it a favor.

In this week’s Today I Learned, Natural History photographer and National Geographic grantee Anand Varma shares some beautiful footage of this ghastly but amazing reproduction behavior.

More about Anand

EDITOR: Laurence Alexander
SERIES PRODUCERS: Chris Mattle and Jennifer Shoemaker
GRAPHICS: Chris Mattle