Texas A&M University, Department of Entomology College Station, Texas
The fall armworm, Spodoptera frugiperda, is comprised of two morphologically identical, but genetically distinct strains. These strains have previously been described as host associated, with the C-strain primarily feeding on corn and sorghum and the R- strain primarily being associated with pasture grasses, Bermuda grass, and rice. Although these strains are genetically distinct, there is evidence that interstrain hybridization can occur in both the lab and the field, but the rate of hybridization has been difficult to determine due in part to limitations of genetic markers. In this study, we used high resolution SNP data to better elucidate patterns of divergence and gene flow between these two S. frugiperda strains. Additionally, using the SNP data, we developed diagnostic assay to rapidly differentiate between fall armyworm strains, and used these tools to test mechanistic hypotheses about reproductive isolation between strains in the field.
