Jewel wasp (Ampulex compressa),

The second sting is administered to the subesophageal ganglion (SEG) and is much more precise, hence the need for paralysis and is significantly longer. The wasp actively searches for the SEG during this sting. The second sting inhibits the cockroach's ability to walk spontaneously, or of its own will, but cockroaches can right themselves and swim while under the influence, and when startled, will jump but not run. It also causes excessive grooming and alterations in the metabolism of the cockroach. The metabolic change is thought to preserve nutrients for the wasp larva. Researchers have simulated this zombie state by injecting procaine into the SEG. They also determined using extracellular bipolar electrodes that neuronal activity was less in stung cockroaches. The venom may disturb the octopaminergic modulation in structures within the roach's ganglion. Basically, it limits the effectiveness of octopamine, the neurotransmitter that controls muscle contraction in sudden movements.[13]