Watch this cockroach karate kick a brain-invading wasp to avoid zombification
It’s like a horror movie come to life.
In a new study, biologists say there’s a certain type of wasp, called the emerald jewel wasp, that has a peculiar way of making sure its young have a head start in life.
The wasp starts by finding a cockroach. Then it rams its stinger into its thorax, paralyzing its legs. Then it stings again — this time injecting its venom directly into the bug’s brain. From then on, the roach is like a “zombie” — alive, but not quite right in the head, and willing to do what the wasp tells it to do.
“It is said to have lost its free will, and hence is often referred to as a zombie ... (the wasp) needs a walking but behaviorally pliable food source for its young that can be led, like a dog on a leash to a distant chamber where it can be safely entombed with the wasp’s egg,” the scientists say in the study.
Tucked away, the roach waits, zombified and compliant, for the egg to hatch and the baby wasp to devour it alive.
But the scientists discovered that the roach is not defenseless — in fact, it’s something of a karate master.
“The cockroach has a suite of behaviors that it can deploy to fend off the zombie-makers, and this starts out with what I call the ‘en garde’ position, like in fencing,” Kenneth Catania, author of the study, said in a news release. “That allows the roach to move its antenna toward the wasp so it can track an approaching attack and aim kicks at the head and body of the wasp, and that’s one of the most efficient deterrents. It’s reminiscent of what a movie character would do when a zombie is coming after them.”
The scientists were able to use high-speed cameras to capture the roaches using their spiny back legs to whack the wasps across the face, smashing them away from their bodies and protecting themselves from becoming “wasp chow.”
The roaches had other methods too. If they couldn’t kick them away at first, the cockroach can “stiff-arm” the stinger and kick at the wasp from that position, and can evade or bite at the wasp as well, according to the study.
“An aggressive defense from the outset was most successful. Thus, for a cockroach not to become a zombie, the best strategy is: be vigilant, protect your throat, and strike repeatedly at the head of the attacker,” the study says.
When performed properly, the defenses saved a majority of the roaches from zombification. Those that went into the “en guarde” position to kick at the wasp avoided being stung 63 percent of the time. The others only made it through 14 percent of the time.
“It’s good advice for any cockroach to put on a strong defense if it doesn’t want to become a zombie. Good advice for the zombie apocalypse as well,” Catania said in a video.