Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2004
Publication Date: 12/1/2004
Citation: Meagher Jr, R.L., Nagoshi, R.N., Stuhl, C.J., Mitchell, E.R. 2004. Larval development of fall armyworm (Lepidoptera: Noctuidae) on different cover crop plants. Florida Entomologist. 87(4):454-460. Interpretive Summary: The fall armyworm is a moth pest whose larvae attack various agricultural crops such as corn, forage grasses, turf, peanuts, cotton, and rice in the eastern and central United States. These moths are present all year in southern Florida, but they migrate northward during spring. Before and during migration, they feed on different host plants including sorghum-sudangrass (SSG), a cover crop that is planted after various vegetable crops are harvested. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, conducted a series of laboratory and field experiments to compare larval development, feeding behavior, and egg-laying preference of fall armyworm host strains on two alternative cover crops. Larvae of both strains developed comparably on corn and SSG, but generally developed poorly on iron-clay cowpeas and sunnhemp. Field plantings of cowpeas and sunnhemp were ignored by fall armyworm in favor of corn. Our results suggest that substitution of cowpeas and sunnhemp for SSG has the potential to reduce migrating populations of fall armyworm in southern and northern Florida, which may impact the numbers of moths migrating further north each season.
Technical Abstract: A series of laboratory and field experiments were conducted to compare larval development and feeding behavior and ovipositional preference of fall armyworm (Spodoptera frugiperda) on a standard host plant, a standard cover crop plant, and two candidate cover crop plants. The results indicate that larvae from different rearing cultures and host strains developed comparably on corn and sorghum-sudangrass, but generally developed poorly on cowpeas and sunnhemp. Larval and ovipositional experiments also suggested a preference for either corn or sorghum-sudangrass. Field plantings of cowpeas and sunnhemp in two locations were ignored by fall armyworm in favor of corn. These studies suggest that cowpeas and sunnhemp have the potential to reduce stepping stone nursery populations of fall armyworm by lengthening developmental time and increasing larval mortality.