The emerald cockroach wasp is one of the most interesting creatures in the entire insect kingdom. It is well-known for preying exclusively on cockroaches, one of humankind’s most hated pests. It is much smaller than its cockroach prey, which is why the emerald cockroach wasp must use cunning chemical and behavioral manipulation to zombify its prey and bring it back to its burrow where it will then lay its eggs on the cockroach host. When these eggs hatch the larvae will consume the cockroach alive and pupate into new adult wasps. This completes a gruesome and life cycle that is only possible because of the incredible abilities of the emerald cockroach wasp.
The most incredible ability of the emerald cockroach wasp is its ability to control the behavior of its host. It attacks cockroaches, delivering a powerful chemical cocktail directly into its brain, that completely subdues the cockroach and turns it into a zombie. The cockroach becomes so passive that, upon delivering the venom to the cockroach brain, the wasp chews parts of the roach antenna off without any resistance from the roach. It then leads the roach back to its burrow by merely tugging on the roach antenna, controlling the roach as if it was leashed.
The emerald cockroach wasp has one of the most accurate stings in the animal kingdom. In order to subdue a cockroach host, it must first deliver one sting to the midsection of the cockroach. This sting will cause temporary paralysis to allow the second injection. In order to effectively paralyze the front legs, however, the wasp must first sting directly into a specific cluster of neurons, known as a ganglion. The precision required to perform such a task is staggering, as a ganglion is far smaller than the stinger of the wasp.
The second shot of venom is perhaps even more difficult, as it targets a very specific ganglion located in the brain of the cockroach. This shot is targeted so that venom disables the pain and threat responses of the cockroach while preserving its ability to move normally.
The venom delivered to the brain of the hapless cockroach is a powerful cocktail that prevents the cockroach from escaping threats or reacting normally to stimuli. In essence, it turns the cockroach into a zombie, only responding to the pulling and prodding of the wasp and exhibiting no will of its own.
As far as insects go the emerald cockroach wasp has a seriously good memory. It must first choose a location to build a burrow and then remember its location. It must then fly out in search of a cockroach, subdue it, and lead it back to the burrow on foot, meaning that the route the wasp took to find the cockroach will be different than the one it will use to bring the cockroach back.
The emerald wasp, as cruel as it can be to the cockroaches it attacks, is simply trying to feed its children. Before the emerald cockroach wasp even approaches prey it first carefully constructs a burrow to which it will lead the cockroach. Once it has successfully captured a cockroach and led it back to the burrow it will lay one to two eggs on the cockroach. It then collects debris and blocks the entrance of the burrow. As the cockroach will make no attempt to escape, this action is meant to protect its offspring from parasites and predators.