How cockroaches use karate kicks to avoid becoming zombies
To escape the "zombifying" sting of emerald jewel wasps, cockroaches deliver swift kicks aimed at the wasps' heads. It's a life-saving tactic to avoid what would be a gruesome fate for the cockroach. The emerald jewel wasp is a parasitic insect with a venomous sting, which it uses to put a cockroach into a passive, zombie-like state. After stinging the cockroach once to paralyze its front legs, it strikes a second time, injecting neurotoxins into the roach's brain. With free will lost, the cockroach can be led by its antennae to the wasp’s burrow, where it will lay an egg on the cockroach. Eventually, the cockroach will be eaten alive by the wasp's larva.
However, cockroaches do have the ability to fight back against the wasps. Biologist Kenneth Catania of Vanderbilt University studied the insect encounters and noted six ways that cockroaches defended themselves, including powerful kicks and biting. In the study, sixty-three percent of the cockroaches that launched any of these defenses against wasps avoided being stung.
Published February 14, 2019.
Transcript
When faced with the prospect of becoming zombie, how does a cockroach fight back?
To escape the "zombifying" sting of emerald jewel wasps, cockroaches deliver swift kicks aimed at the wasps' heads.
With the mighty force of its karate kicks.
Its foe, the emerald jewel wasp, is a parasitic insect with a powerful, “zombifying” sting.
When the wasp attacks, it latches onto the cockroach and stings its thorax.
The first sting temporarily paralyzes the roach’s front legs.
Then the wasp stings a second time, injecting venom into the roach’s brain.
The neurotoxins in the venom put the roach into a passive, zombie-like state.
With free will lost, the cockroach can be led by its antennae to the wasp’s burrow …
where the wasp will lay its egg on the cockroach and seal the exit with debris.
Eventually, the cockroach will be eaten alive by the wasp’s larva.
However, not all jewel wasp attacks result in gruesome death for the cockroach.
When Kenneth Catania of Vanderbilt University studied these insect encounters, he noted six ways that American cockroaches defend themselves.
Stilt-standing to elevate the body and neck, helping to evade lunging attacks
Kicking vigorously with their spiny legs, often aiming at the wasp’s head
Attempting escape after initial contact with the wasp’s antennae or leg
Turning rapidly to dislodge the wasp’s jaws from its pronotum
Using its sharp leg spines to rake, stab, and parry the stinger
Biting the wasp to keep it from stinging
63% of the cockroaches that launched any of these defenses against wasps avoided being stung.
