Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2004
Publication Date: December 1, 2004
Citation: Nagoshi, R.N., Meagher Jr, R.L. 2004. Behavior and distribution of the two fall armyworm host strains in Florida. Florida Entomologist. 87(4):440-449. Interpretive Summary: Fall armyworm (FAW) is a significant pest of maize, sorghum, forage grasses for livestock, turf grasses, rice, cotton and peanuts. It is a migratory pest that cannot survive freezing winters, hence the infestation of most of North America stems from populations overwintering in south Florida and parts of Texas. Controlling FAW in these relatively localized overwintering areas prior to migration could reduce FAW damage in more northern states. However, complicating our understanding of FAW field behavior is the existence of two strains that display differences in resistance to certain pesticides and host plant preference. The biology of the host strains is poorly understood and this lack of knowledge precludes accurate predictions of fall armyworm population behavior in the field. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, USDA, ARS, review recent studies examining host strain behavior and discuss the potential relevance of these results to the development of effective regional management strategies that can proactively mitigate the economic impact of this pest. This review will be an important guide to future research.
Technical Abstract: The fall armyworm, Spodoptera frugiperda (J. E. Smith) is a periodic and significant economic pest in most of the continental U.S., capable of causing substantial losses in maize, sorghum, forage grasses, turf grasses, rice, cotton, and peanut production. Because fall armyworm do not survive conditions of prolonged freezing, most of the infestations in the continental United States derive from annual migrations of populations wintering in southern Florida and southern Texas. This localization of the winter populations theoretically provides an opportunity to dramatically reduce the migratory population. Unfortunately, the biological information necessary to develop an area-wide management strategy for this pest has been slow in coming, in large part because of the existence of two morphologically identical but physiologically distinct host strains that has complicated efforts to understand and predict fall armyworm behavior in the field. This paper reviews recent studies describing new methods of strain identification that greatly enhance our capacity to investigate and understand fall armyworm population biology. Preliminary results suggest that at least one strain, whose primary target is corn, might be particularly amenable to a regional management program.