SEASONAL INCIDENCE OF FALL ARMYWORM (LEPIDOPTERA: NOCTUIDAE) PUPAL PARASITISM IN CORN BY DIAPETIMORPHA INTROITA AND CRYPTUS ALBITARSIS¹ (HYMENOPTERA: ICHNEUMONIDAE)

Diapetimorpha introita (Cresson) occurred from May to November and was the primary parasitoid of fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), pupae in corn fields at Tifton, GA, from 1983 to 1985. Another previously unreported pupal parasitoid of FAW, Cryptus albitarsis (Cresson), occurred only during a single sample conducted in November 1984. Rates of parasitism averaged 5.2% (range 0–23.7%) and 8.4% (range 0–50.0%), respectively, during 1983 and 1984, with the highest rate occurring in September to November of each year. In a limited study conducted in September and October 1985, total pupal parasitism averaged 33.3% (range 0–44.4%). Predation was the primary mortality factor, averaging 44.7, 37.8, and 95.8%, respectively, during 1983, 1984, and 1985. Predators found either in FAW pupation tunnels or feeding directly upon pupae were earwigs, Labidura riparia (Pallas); nonidentified carabid beetles; wireworms, Conoderus sp.; and the imported fire ant, Solenopsis invicta Buren. These studies indicate parasitoids and predators of FAW pupae play a primary role in regulating FAW populations following their development in corn and likely significantly reduce the numbers that subsequently disperse into new habitats for oviposition on other crops.