Weird, Wonderful Wildlife #2 – The Jewel Wasp

I never thought I could ever feel bad for cockroaches – they eat garbage, carry diseases like salmonella and gastroenteritis, and can allegedly survive a nuclear holocaust – until I read about the female jewel wasp. She is beautiful but deadly and has the unique ability to zombify cockroaches so they become willing participants in their own gruesome demise. I’ve read that this insect is what inspired the chest bursters in the movie Alien, and if that’s true, it makes perfect sense. Nothing is known about their reproduction in the wild, but in captivity, the jewel wasp mates only once, and then she has enough fertilized eggs to enslave dozens of roaches. She will seek out a prime candidate and when she finds her target, she goes in, not for the kill, but for the zombification. She bites the roach’s exoskeleton and then stabs its underbelly to paralyze its front legs so that it can’t fight back. Then, the roach faces a drawn out enslavement and eventual death. The wasp has a two millimeter long stinger that is studded by bumps that are either shaped like bells or domes that allows her to feel her way through the roach’s brain with the precision of a skilled neurosurgeon. The bells and domes help her find the sub and supra esophageal ganglion, which she injects with venom before withdrawing her stinger. You’d think at this point the roach would try like hell to get out of Dodge, but what he does instead is truly bizarre. He will begin obsessively grooming while she goes in search of a burrow. Scientists aren’t sure exactly what purpose the grooming serves, but some think it’s either meant to distract the roach or to provide a clean environment for the larvae. By the time she returns, the roach is clean….and completely brainwashed. This is where things get violent!

She bites off one of his antennae and drinks the hemolymph (the insect version of blood) which acts as a type of wasp Gatorade. Once she’s regained a little energy, she bites the antennae stub and leads the roach, which at this point is acting like an obedient puppy, to the chamber she found. She shoves him in and lays a single egg on his leg before leaving to find pebbles with which she will reenact The Cask of Amontillado; the irony is that if the roach could remove the egg, it would fully recover, but all it does is lay there and watch the wasp seal off its sarcophagus. It will remain alive, albeit in a sort of stasis, until the larva hatches two days later. If you thought Mama was bad, Baby is even worse – it will chew a hole in the roach’s abdomen, drinks the hemolymph and then eats its way through the organs, saving the nervous system for last. Once the roach is finally dead, the larva secretes an antimicrobial disinfectant to protect itself while it incubates for another month before fully maturing. If I were a cockroach, I’d rather be sprayed with Raid – at least that would kill me rather quickly!

Sources:

scientificamerican.com/article/how-a-wasp-turns-cockroaches-into-zombies1

wired.com/2014/02/absurd-creature-of-the-week-jewel-wasps