Linking vector biology, transmission, and genome architecture in southeastern orthotospoviruses.

Orthotospoviruses remain major threats to specialty and row crops in the southeastern United States through thrips-borne, persistent-propagative transmission. We synthesize the emergence and biology of tomato spotted wilt virus (TSWV) and soybean vein necrosis virus (SVNV), with context from impatiens necrotic spot virus, groundnut ringspot virus, and tomato chlorotic spot virus (TCSV). TSWV has a broad host range and global importance, whereas SVNV has a narrower known host range but continues to expand across soybean-producing regions. Comparative genomic analyses suggest distinct evolutionary patterns: TSWV shows greater structural plasticity in the S and M segment intergenic regions, whereas SVNV retains more conserved intergenic architectures and hairpin structures. These differences provide a framework for comparing orthotospovirus emergence, but their epidemiological significance remains unevenly resolved across virus-vector systems. Management has likewise diverged, with single-gene resistance in tomato and pepper repeatedly overcome by resistance-breaking TSWV variants, while multigenic hairpin constructs targeting all five viral ORFs provide broader protection against TSWV and TCSV. Together, these comparisons highlight how genome architecture and vector biology shape orthotospovirus emergence and management in the Southeast.