Maybe this has been discussed on the forum previously, but I've just come across this information on wikipedia, which says:
"The emerald cockroach wasp or jewel wasp (Ampulex compressa) is a solitary wasp of the family Ampulicidae. It is known for its unusual reproductive behavior, which involves stinging a cockroach and using it as a host for its larvae. It thus belongs to the entomophagous parasites. "
http://en.wikipedia.org/wiki/Emerald_cockroach_wasp
"The emerald cockroach wasp or jewel wasp (Ampulex compressa) is a solitary wasp of the family Ampulicidae. It is known for its unusual reproductive behavior, which involves stinging a cockroach and using it as a host for its larvae. It thus belongs to the entomophagous parasites. "
http://en.wikipedia.org/wiki/Emerald_cockroach_wasp