Hexbyte – Tech News – Ars Technica | Cockroaches deliver karate kicks to avoid being turned into “zombies”

Hexbyte – Tech News – Ars Technica |

Dead roach walking —

New ultra-slow-motion footage captures aggressive roach defense mechanisms


Hexbyte - Tech News - Ars Technica | A wasp climbs atop a cockroach against a white background.
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The jewel wasp administers two stings: one to paralyze the legs, the other to make the roach her zombie slave.

If you ever want to witness just how horrifyingly “red in tooth and claw” nature can be, you only have to look to the emerald jewel wasp. The female of the species is known for stinging unsuspecting cockroaches with a nasty venom that turns the roach into her docile slave. That way she can lay her eggs in the still-living roach and bury it alive, ensuring her offspring have something to eat when they hatch. Even if you don’t like cockroaches, it’s a pretty gruesome fate—they become the walking dead.

But it turns out that the poor roach is not without defenses of its own, according to a new paper in Brain, Behavior and Evolution with the rather puckish title, “How Not To Be Turned Into a Zombie.” Roaches can use their hard, spiky legs as weapons, even delivering wide sweeping kicks to ward off an attacking jewel wasp. It’s the most detailed study yet of how roaches fight off attacks to turn them into insectoid zombies.

“The cockroach has a suite of behaviors it can deploy to fend off the zombie makers.”

The author, Vanderbilt University’s Ken Catania, has a knack for creatively studying the aggressive behavior of various creatures; his specialty is predator/prey interactions. Back in 2016, he experimentally verified naturalist and explorer Alexander von Humboldt’s 19th-century account of electric eels in Venezuela aggressively leaping up and stunning horses with a series of high-voltage discharges. (Part of that experiment involved LED lights mounted on a fake alligator head, attached with strips of conductive tape, to better visualize those discharges. Because of course it did.)

This time around, he investigated the defense mechanisms of the American cockroach (Periplaneta americana) against female jewel wasps (Ampulex compressa, aka emerald cockroach wasp). Catania had read accounts of roaches trying to defend themselves from these devastating attacks and thought they warranted a closer look—in this case, with ultra slow-speed videography, the better to capture the intricacies of the interactions.

  • A roach will assume a stilt-standing posture to evade the jewel wasp’s attack.

  • The cockroach setting up a kick against an approaching wasp.

  • The roach swings its leg like a baseball bat to sweep the wasp away.

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