Scientific Video Shows Cockroach Kicking Wasp to Prevent Its Zombification

A new study's video shows an insect battle royale.

Make no mistake, zombies are very real. Sure, zombies of the human variety aren’t going to wander down your street, The Walking Dead-style, any time soon, but zombies of a different sort are scuttling around, mindlessly wandering towards a doomed existence. The American cockroach, for example, spends a good amount of its time trying not to become a zombie at the metaphorical hands of emerald jewel wasps. If it doesn’t put up the right defense, it’s brain-warped toast.

In the video above, you can see what happens when a cockroach successfully defends itself against zombification. These guarding mechanisms are the focus of a study published Wednesday in the journal Brain, Behavior and Evolution. Study author and Vanderbilt University biologist Ken Catania, Ph.D., carefully filmed and analyzed 55 cockroach-versus-wasp battles and discovered that certain moves can help a cockroach avoid harm.

In this situation, harm is something a cockroach really doesn’t want to happen because a sting from a wasp is extremely bad news. The goal of an emerald jewel wasp is to zombify a cockroach with a sting to the brain.

If it’s stung, the cockroach’s nervous system becomes overwhelmed by venom and the insect becomes passive. The wasp then leads the helpless and thoughtless cockroach to a hole, where the wasp really does the cockroach dirty: It deposits its eggs into the cockroach, leaves, and seals up the exit to the hole, leaving its zombie victim behind. The cockroach is later slowly eaten alive by the developing wasp larva it’s incubating.

Not a good deal for the cockroach! So, to avoid becoming wasp food, the cockroach has developed some techniques to fight back: It poses in an “on-guard” position, allowing it to detect and evade the wasp’s lunging attack, then it counters with a swift kick, a wiggle, or a bite.

A frame-by-frame capture of the fight.

Catania Lab

Despite these skills, a cockroach isn’t always ready to go into fight mode. In this study, Catania had the two bugs encounter each other gladiator-style, with the cockroach entering a see-through chamber two minutes after its enemy wasp did the same.

Catania filmed each encounter with a specialized, high-speed camera and saw that 28 out of the 55 cockroaches didn’t defend themselves at all, apparently taken by surprise. Each was quickly grasped by the wasp and 24 were stunned within the first three minutes of the encounter.

Meanwhile, 27 of the cockroaches did defend themselves from the wasp attack. The attack method most preferred in this group of cockroaches was the kick — 14 females and 13 males each round-housed their way into a brief moment of safety. Their victories were short-lived, though: 10 of these cockroaches still ended up stung within three minutes. Still, 17 of the cockroaches were able to keep the wasp at bay for three minutes or more, which Catania describes as a “successful defense.”

Is it still successful if you end up a zombie? Who can say. But at least these bugs didn’t go down without a fight.

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