Seasonal Parasitism Rates, Host Size, and Adult Emergence Pattern of Parasitoids of the Fall Armyworm, Spodoptera frugiperda (J. E. Smith), with Emphasis on Ophion flavidus Brulle (Hymenoptera: Ichneumonidae)

Abstract

Eight species of parasitoids were reared from fall armyworm, Spodoptera frugiperda (J. E. Smith), larvae. The ichneumonid Ophion flavidus Brulle was the most common species, parasitizing 3.8% of host larvae, and Archytas marmoratus (Townsend) parasitized 2.5% of hosts. O. flavidus primarily used medium and large larvae, while A. marmoratus was recovered from small, medium, and large larvae in ca. equal percentages. O. flavidus adults emerged ca. 9 days after their hosts and A. marmoratus emerged 4 to 15 days after the hosts. Winthemia rufopicta Bigot adult emergence coincided with host adult emergence. In laboratory studies conducted on O. flavidus at 26 ±C, mean times were: egg and larval period, 9.6 days; cocoon stage, 16.7 days; and adult stage, 11.3 days. Sex of O. flavidus offspring appeared to be determined by a haplodiploid mechanism, with mated females producing male and female offspring and unmated females producing only males.