Host-parasitoid-pathogen interactions amongPieris rapae(L.),Apanteles glomeratus(L.), and the granulosis Virus (GV) ofP. rapaewere studied using laboratory and field populations. Survival ofA. glomeratusin GV-infectedP. rapaedepended on the time between oviposition by the parasitoid in a larva ofP. rapaeand ingestion of GV by the larva; parasitoids did not survive in host larvae exposed to GV on or before 4 days after oviposition at 25°C. Survival ofA. glomeratuswas less inP. rapaein which the GV disease was severe than in lightly infected larvae.