Tobacco streak virus (TSV), an Ilarvirus, was first confirmed as a viral pathogen of tobacco in 1936 (Johnson 1936) and first reported in North American soybean in 1969 (Fagbenle and Ford 1970). TSV has a wide host range with strains able to infect at least 140 different plant genera, including crop, ornamental, and wild species (Fulton 1948). Due to its extensive host range and strain adaptations, TSV is found in commercial crops worldwide. Since 1969, however, TSV has not been a problem on soybean or commonly reported until the 2013 season, when it was found in fields throughout Iowa. A similar situation is found throughout the Midwest, with TSV being reported in recent years in Illinois, Kansas, and Wisconsin, as well as Ontario, Canada.