Dementor Wasp (Ampulex dementor)

Scientists recently discovered the dementor wasp in southeast Asia. They are flying insects that turn cockroaches into zombies. They do this by injecting the belly of cockroaches with venom, which turns the roach into a passive zombie. 

It turns them into zombies by blocking the receptors of the neurotransmitters of octopamine. Octopamine is involved in the initiation of spontaneous responses. Blocking it makes cockroaches incapable of controlling their movements.