Behavior
Adult wasps lay their eggs in tobacco hornworm larvae in their 2nd or 3rd instar and at the same time injects symbiotic viruses into the hemocoel of the host along with some venom. The viruses knock down the internal defensive responses of the hornworm. The eggs hatch in the host hemocoel within two to three days and simultaneously release special cells from the egg's serosa. These special cells, called teratocytes, grow to become giant cells visible to the naked eye. The teratocytes secrete hormones which work in tandem with the virus and the wasp venom to arrest the development of the host. Following hatching in the caterpillar, the wasp larvae will undergo 2 molts inside the host caterpillar’s hemocoel and, after 12 to 16 days post oviposition, the 3rd instar wasp larvae will emerge from the caterpillar and spin cocoons from which the adult wasps fly about 4 to 8 days later.Not all of the parasite larvae will successfully emerge from the host. Dissection of post-emergence caterpillars revealed three categories of remaining larvae:
# Dead or dying wasp larvae, in various stages of development, which had been partially or completely encapsulated by the host's immune system. The parasite has significant immunosuppressive capabilities, but the host's immune system is able to partially recover over a period of several days, so these may have been encapsulated at a very late stage.
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# Wasp larvae that were alive, but had exhibited reduced growth compared to the other larvae and might not have been able to reach the second instar stage.
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# Wasp larvae in the second instar, similar to those which had emerged successfully.
This insect has the shortest flagellated spermatozoa in animals, being 6.6 µm long , 8800 times shorter than the longest ones .
Wasp pupae may themselves be parasitized by chalcid wasps of the genus ''Hypopteromalus''.
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