The Emerald Cockroach Wasp
Categories : Evolution, Things that make you go "WOW!"
Editor : DaveScot
published: vendredi 5 janvier 2007 14:29:40
The emerald cockroach wasp (Ampulex compressa, also known as the jewel wasp) is a parasitoid wasp of the family Ampulicidae. It is known for its reproductive behavior, which involves using a live cockroach (specificially a Periplaneta americana) as a host for its larva. A number of other venomous animals which use live food for their larvae paralyze their prey. Unlike them, Ampulex compressa initially leaves the cockroach mobile, but modifies its behaviour in a unique way.
As early as the 1940s it was published that wasps of this species sting a roach twice, which modifies the behavior of the prey. A recent study using radioactive labeling proved that the wasp stings precisely into specific ganglia. Ampulex compressa delivers an initial sting to a thoracic ganglion of a cockroach to mildly paralyze the front legs of the insect. This facilitates the second sting at a carefully chosen spot in the cockroach’s head ganglia (brain), in the section that controls the escape reflex. As a result of this sting, the cockroach will now fail to produce normal escape responses.