D3453: The fall armyworm host strains: Regional variations on a theme

The noctuid moth Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), commonly called the fall armyworm (FAW), is an important agricultural pest native to the Americas that has become a global concern with its 2016 discovery in western Africa followed by infestations detected in India (2018), China (2018-2019), and Australia (2020). The species is subdivided into two populations that differ in their plant host specificity. These were designated as host strains with the C-strain typically the majority in corn, sorghum, and cotton infestations while the R-strain predominates in turf, pasture, millet, and alfalfa. Data will be presented describing regional differences in the behaviors of the host strains and how they might impact strain divergence and speciation.