Injection of Venom by a Wasp into Cockroach Brain

Direct Injection of Venom by a Predatory Wasp into Cockroach Brain and makes it a zombie



In this article, we provide direct evidence for injection of venom by a wasp into the central
nervous system of its cockroach prey. Venomous predators use neurotoxins that generally act at the neuromuscular junction, resulting in different types of prey
paralysis. The sting of the parasitoid wasp Ampulex
compressa is unusual, as it induces grooming behavior,
followed by a long-term lethargic state of its insect prey,
thus ultimately providing a living meal for the newborn
wasp larvae. These behavioral modifications are induced
only when a sting is inflicted into the head. These unique
effects of the wasp venom on prey behavior suggest that
the venom targets the insect’s central nervous system.




The mechanism by which behavior modifying compounds in the venom transverse the blood-brain barrier
to induce these central and long-lasting effects has been
the subject of debate. In this article, we demonstrate that
the wasp stings directly into the target ganglia in the
head of its prey. To prove this assertion, we produced
“hot” wasps by injecting them with 14C radiolabeled
amino acids and used a combination of liquid scintillation and light microscopy autoradiography to trace radiolabeled venom in the prey. To our knowledge, this is
the first direct evidence documenting targeted delivery
of venom by a predator into the brain of its prey.