Skip to main content
ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Insect Behavior and Biocontrol Research » Research » Publications at this Location » Publication #323869
Title: Demonstration using field collections that Argentina fall armyworm populations exhibit strain-specific host plant preferences

Author
item MURA, M - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item Nagoshi, Rodney
item DOS SANTOS, DANIEL - Consejo Nacional De Investigaciones Científicas Y Técnicas(CONICET)
item HAY-ROE, MIRIAN - University Of Florida
item Meagher, Robert - Rob
item VILARDI, J - Universidad De Buenos Aires

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2015
Publication Date: 10/1/2015
Citation: Mura, M.G., Nagoshi, R.N., Dos Santos, D.A., Hay-Roe, M.M., Meagher Jr, R.L., Vilardi, J.C. 2015. Demonstration using field collections that Argentina fall armyworm populations exhibit strain-specific host plant preference. Journal of Economic Entomology. 108(5):2305-2315.
DOI: https://doi.org/10.1093/jee/tov203

Interpretive Summary: The fall armyworm is a major economic pest throughout the Western Hemisphere, where it feeds on corn, cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Studies in the U.S. and parts of South America have shown that this moth species has two host strains that either attack corn and sorghum (the corn strain) or that attack rice, turf grass and alfalfa (the rice strain). However previous studies in Argentina have been inconclusive and some researchers there suggest that the host strains do not exist. Scientists from the USDA, Agricultural Research Service, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, in collaboration with colleagues from several scientific organizations in Argentina, collected larvae and moths from the different field sites throughout Argentina. Our results confirmed the existence of both the corn and rice strains in Argentina and that they retained their host preferences. Additionally, the data showed that the strain behaviors observed were consistent with those with other areas in the Western Hemisphere.

Technical Abstract: Spodoptera frugiperda, the fall armyworm, is a major economic pest throughout the Western Hemisphere of corn (maize), cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Studies in the United States, the Caribbean, and Brazil demonstrated the existence of two subpopulations (previously designated “host strains”) that differ in their choice of plant host. Specifically, the corn strain is preferentially found in corn and sorghum, while the rice strain is dominant in rice, turf grass, and alfalfa. However, inconsistent results were reported in surveys of fall armyworm in Argentina, with some indicating that the host plant preferences of the two strains might be compromised or even nonexistent. If correct, this would complicate efforts to control this pest by considerably expanding the range of habitats that would have to be considered as potential sources for fall armyworm infestations in specific crops. A reexamination of Argentine fall armyworm, this time with field collections rather than the laboratory colonies used in previous studies, confirmed the existence of the two strains and their host preferences. Specifically, the corn strain was consistently the majority population infesting corn and was usually so in sorghum, while the rice strain was predominant in pasture/turf grasses and alfalfa. The one outlier was a collection from rice, which had a corn strain majority. Overall, the data were generally consistent with strain behaviors observed in other areas of the Western Hemisphere.