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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Insect Control and Cotton Disease Research » Research » Publications at this Location » Publication #309238

Title: Modeling seasonal migration of fall armyworm moths

Author
item Westbrook, John
item Nagoshi, Rodney
item Meagher, Robert - Rob
item FLEISCHER, SHELBY - Pennsylvania State University
item Jairam, Siddarta

Submitted to: International Journal of Biometeorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2015
Publication Date: 6/7/2015
Citation: Westbrook, J.K., Nagoshi, R.N., Meagher Jr, R.L., Fleischer, S.J., Jairam, S. 2015. Modeling seasonal migration of fall armyworm moths. International Journal of Biometeorology. 60:255-267.

Interpretive Summary: The fall armyworm is a highly mobile insect pest of corn and many other crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature, but must repeat a series of northward migratory flights each spring if it is to re-infest a succession of cropping areas in temperate regions. Recent genetic analyses have characterized migratory pathways from overwintering regions in southern Texas and southern Florida, but knowledge is lacking on the atmosphere’s role in influencing the distance, direction, and timing of migratory flights. An atmospheric dispersal model (HYSPLIT) was used to simulate long-distance migratory flight patterns of fall armyworm moths from two distinct overwintering source areas. Model simulations identified regions that are expected to be dominated by migrants from either the Florida or Texas source locations, as well as two areas in Alabama-Georgia and Pennsylvania-Maryland where there is a strong probability of overlap between the migratory populations. Coupling of atmospheric modeling with genetic distribution analysis contributes to knowledge of fall armyworm population ecology on a continental scale, and will aid in the prediction and interpretation of inter-annual variability of pest migration patterns including those in response to climatic change.

Technical Abstract: Fall armyworm, Spodoptera frugiperda (J. E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature, but must repeat a series of northward migratory flights each spring if it is to re-infest a succession of cropping areas in temperate regions. The northward limit of the overwintering region for North America extends to the southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these overwintering regions, but knowledge is lacking on the atmosphere’s role in influencing the distance, direction, and timing of migratory flights. The HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model was used to simultaneously simulate long-distance migratory flight patterns of fall armyworm moths from distinct overwintering source areas. Model simulations identified regions that are expected to be dominated by migrants from either the Florida or Texas source locations, as well as two areas in Alabama-Georgia and Pennsylvania-Maryland where there is a strong probability of overlap between the migratory populations. This predicted migratory pattern based on air trajectory simulations closely corroborates a previous migratory map based on the distribution of fall armyworm haplotype profiles. The capacity to combine atmospheric modeling with genetic haplotype distribution analysis provides an efficient method for extrapolating and verifying long distance insect flight behaviors. The results contribute to knowledge of fall armyworm population ecology on a continental scale, and will aid in the prediction and interpretation of inter-annual variability of pest migration patterns including those in response to climatic change.