By Anna Hagemann and Madalyn Shires et.al
Wheat Streak Mosaic Virus (WSMV) is a viral disease that infects the Poaceae family, also known as grasses. WSMV has been reported in South Dakota wheat fields and is also a major wheat disease for Great Plains states in 2025. The virus is sweeping across the state and is rampant in winter wheat. There is also risk that the virus will be transferred to spring wheat, which has significantly less resistance to wheat viruses. WSMV is detrimental, as it spreads rapidly and can significantly reduce yield. The virus transmits quickly; therefore, it is essential to diagnose it in a timely manner to manage it properly. Similar diseases, including High Plains Wheat Mosaic Virus, and Triticum Mosaic Virus are associated with WSMV. They are transmitted by the same vector and often co-infect alongside one another.
Transmission
This virus is transmitted by the wheat curl mite called Aceria tosichella. In several cases, WSMV onsets following extensive growth of volunteer wheat. Volunteer wheat from previous harvests is often a result of broken kernels released from hailstorms. The environment provided by this volunteer wheat is the perfect setting for the mite and the virus to thrive. It is important to note that the spread of the disease can occur between overlapping areas of spring and winter wheat as well, moving into different growing seasons. Therefore, early planting can add additional problems, as the virus transfers from the remaining spring wheat to winter wheat in the early fall.