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

The effect of an ectoparasitic nematode, Noctuidonema guyanense Remill et & Silvain (Nematoda: Aphelenchoididae), on adult longevity and egg fertility in Spodoptera frugiperda (J. E. Smith) was studied in the la boratory. Infestation of S. frugiperda was achieved by crossing field- collected, infested moths with virgin, laboratory-reared moths. In 198 9-1990, adult longevity of infested male moths was reduced by about 30 %, whereas female longevity was reduced by about 15%. Longevity of fem ale moths also was decreased by the nematode in 1991. Survival of fiel d-collected moths was 63% less in infested moths than in noninfested m oths 3 days after their confinement in the laboratory. Fecundity for i nfested and noninfested moths was similar in 1989-1990. However, in 19 90, fertility was depressed in infested female moths by up to 20%. Amo ng insects held under three constant temperature regimes (20, 25, and 30-degrees-C) in 1991, egg hatch was affected most at the lowest tempe rature. This is the first evidence of an ectoparasitic nematode affect ing the biology of adult S. frugiperda. (C) 1994 Academic Press, Inc.