Cockroaches employ swift kicks to stop wasps turning them into ‘zombies’, study finds
'It's reminiscent of what a movie character would do when a zombie is coming after them'
Jewel wasps are parasites that lay their eggs on the body of cockroaches, which are then eaten alive by the larvae when they emerge.
To prevent the larger insect from trying to escape as it is being eaten, the wasp delivers a sting to the cockroach's brain that leaves it unwilling to run away.
This process is known as “zombification” by scientists, as the wasps appears to effectively rob their prey of any free will.
Now a biologist at Vanderbilt University has found that cockroaches do not always go willingly to this grisly fate, and are capable of fighting back using swift kicks to beat away approaching wasps.
"The cockroach has a suite of behaviours 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," said Professor Ken Catania.
"That allows the roach to move its antenna towards 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.”
Professor Catania had previously heard reports of cockroaches defending themselves from attack, but needed to employ ultra-slow-speed videos of the behaviour to see it in action.
A kick delivered with a spiny back leg was able to fend off wasp attack in 63 per cent of cases, at least for adult wasps.
Young cockroaches were far less lucky, as their defence barely ever worked.
In his experiments, which were published in the journal Brain, Behavior and Evolution, Professor Catania noted that the most aggressive cockroaches also followed up with bites to the wasp's bodies.
In this manner, vigilant individuals were able to avoid a terrible fate.
"The wasp usually figures out there's a smaller and less defensive cockroach out there to be had,” said Professor Catania.