SELECTION OF NOSEMA-PYRAUSTA (MICROSPORIDIA, NOSEMATIDAE)-INFECTED OSTRINIA-NUBILALIS (LEPIDOPTERA, PYRALIDAE) EGGS FOR PARASITIZATION BY TRICHOGRAMMA-NUBILALE (HYMENOPTERA, TRICHOGRAMMATIDAE)

Trichogramma nubilale Ertie and Davis females were offered a choice be tween egg masses of the European corn borer, Ostrinia nubilalis (Hubne r), infected with the microsporidium Nosema pyrausta (Paillot) and non -infected egg masses. Nosema pyrausta-infected O. nubilalis eggs were smaller (weight) than non-infected host eggs. Trichogramma nubilale fe males did not discriminate between infected and N. pyrausta-free egg m asses. This microsporidian infection did not significantly affect the sex ratio of emerging wasps. Significantly fewer and smaller adult par asitoids emerged from infected host eggs than from noninfected eggs.