Larval parasitoids collected from overwintering European corn borer (Lepidoptera: Pyralidae) in Pennsylvania.
Three imported parasitoids emerged from larvae of Ostrinia nubilalis from overwintering sites in maize in Pennsylvania in 1990. Macrocentrus grandii was the principal parasitoid, emerging from 17.4% of the overwintering larvae collected. The other specimens, Lydella thompsoni and Eriborus terebrans [Diadegma terebrans], were recovered from less than 3% of the overwintering larvae. The entomogenous fungus Beauveria bassiana appeared in 8.8% of the larvae. In total, 34% of the larvae produced an identifiable parasitoid or pathogen and another 10.2% were killed by unknown causes.