Distribution and Prevalence of an Ectoparasitic Nematode, Noctuidonema guyanense, on Moths of The Fall Armyworm (Lepidoptera: Noctuidae) in the Tropical Americas

Moths of the fall armyworm, Spodoptera frugiperda (J. E. Smith), collected from locations extending from northern South America, the Caribbean basin, Central America, Mexico, Texas, to Florida, and Bermuda, were examined for Noctuidonema guyanense Remillet and Silvain, an ectoparasitic nematode of adult Lepidoptera. Noctuidonema was recovered from all locations where the fall armyworm was collected. This parasitic nematode was previously only known to occur in French Guiana and Guadeloupe. Parasitism was generally around 35%, but was variable at different locations ranging from nearly 0% to about 90%. Although the number of nematodes per moth varied among locations, mean infestation ranged from 30 to 40 specimens per host. Noctuidonema also was recovered from the black cutworm, Agrotis ipsilon (Hufnagel), a host on which it previously had not been known to occur.