EFFECT OF AN ECTOPARASITIC NEMATODE, NOCTUIDONEMA-GUYANENSE, ON ADULT LONGEVITY AND EGG FERTILITY IN SPODOPTERA-FRUGIPERDA (LEPIDOPTERA, NOCTUIDAE)

The effect of an ectoparasitic nematode, Noctuidonema guyanense Remillet & Silvain (Nematoda: Aphelenchoididae), on adult longevity and egg fertility in Spodoptera frugiperda (J. E. Smith) was studied in the laboratory. Infestation of S. frugiperda was achieved by crossing field-collected, infested moths with virgin, laboratory-reared moths. In 1989-1990, adult longevity of infested male moths was reduced by about 30%, whereas female longevity was reduced by about 15%. Longevity of female moths also was decreased by the nematode in 1991. Survival of field-collected moths was 63% less in infested moths than in noninfested moths 3 days after their confinement in the laboratory. Fecundity for infested and noninfested moths was similar in 1989-1990. However, in 1990, fertility was depressed in infested female moths by up to 20%. Among insects held under three constant temperature regimes (20, 25, and 30-degrees-C) in 1991, egg hatch was affected most at the lowest temperature. This is the first evidence of an ectoparasitic nematode affecting the biology of adult S. frugiperda. (C) 1994 Academic Press, Inc.