Found these tiny wasps parasitizing a mantis egg case or ootheca in Argentina. You can see the tiny wasps rearing up and inserting their long ovipositors. In higher members of the order Hymenoptera, the female ovipositor is modified into the sting (only female bees, wasps, and ants can sting.)
‘Parasitoids’ are distinguished from ‘parasites’ in several ways. A parasitoid insect lays one or multiple young on or into a single host organism–often a juvenile or egg. The young develop inside the host, which may live on for some time, but almost always ultimately succumbs to the creature devouring it from the inside out. Anyone who has watched the movie Aliens may find this sequence of events familiar. Parasitoids thus are not true parasites as they kill their host, but not quite predators, in that they consume only one prey item during the course of their lifespan.