Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2009
Publication Date: 12/1/2009
Citation: Nagoshi, R.N., Fleischer, S., Meagher Jr, R.L. 2009. Texas is the overwintering source of fall armyworm in central Pennsylvainia: implications for migration into the northeastern United States. Journal of Economic Entomology. 38(6):1546-1554. Interpretive Summary: Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae) or fall armyworm is an important agricultural pest of a number of crops in the western hemisphere. Fall armyworm does not survive severe winters so the infestations affecting North America originate from migrants that overwinter in Florida and Texas. In this paper, scientists from USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Fl looked at molecular methods that can distinguish the offspring from these two geographically distant populations were used to investigate the origin of the fall armyworm infesting central Pennsylvania and by inference the northeastern United States. The results indicate that most, if not all, the fall armyworm were derived from Texas populations, with only limited or sporadic contributions from Florida. Therefore, efforts to predict or mitigate infestations in Pennsylvania and surrounding areas should focus on conditions in the overwintering areas of Texas that influences the timing and severity of fall armyworm migration.
Technical Abstract: Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), infestations in most of North America arise from annual migrations of populations that overwinter in southern Texas and Florida. Cytochrome Oxidase I haplotype profiles within the fall armyworm corn-strain, the subgroup that preferentially infests corn (Zea mays L.), can differentiate the Texas and Florida populations. We use this molecular metric to demonstrate that fall armyworm in central Pennsylvania originate from Texas, indicating the existence of a migratory pathway from Texas to the northeastern United States. These results were compared to historical trapping data for fall armyworm and another migratory noctuid, corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in the Pennsylvania and Maryland corn producing areas to better define lepidopteran migratory pathways into Pennsylvania.