Teratocytes: Growth and numbers in the hemocoel of Heliothis virescens attacked by Microplitis croceipes

Abstract

When the egg of Microplitis croceipes hatches in its host, Heliothis virescens, spherical cells (teratocytes) from the extraembryonic membrane are released into the host's hemolymph. Approximately 750 teratocytes are liberated from the parasitoid egg, and they average 10.5 μm in diameter when released. These cells increase in size, reaching a maximum average diameter of 140 μm in 8–9 days. The developing parasitoid emerges from the host in 9 days. The host remains alive and contains approximately 750 teratocytes, indicating that the teratocytes are not consumed by the parasitoid. These results suggest that teratocytes are not a direct source of nutrition for the developing parasitoid. Observations showed that encapsulation can occur in the presence of teratocytes even following the emergence of the parasitoid. The results indicate that teratocytes do not block the host's ability to encapsulate certain foreign materials within its hemocoel.