Wheat streak virus is vectored by the wheat curl mite. In spring, mites infect plants along field margins, especially along areas where volunteer wheat is growing. Infections potentially start in fall but symptoms may not be apparent until spring in winter wheat. The virus causes yellowing, browning, and stunting of plants, first appearing as yellow mottling or streaking in leaves. Plants infected in fall tend to have fewer tillers and more severe stunting than plants infected in spring. Drought may intensify the virus effects, presence of volunteer wheat, and previous exposure to hail can drasticially increase your risk of infection.
Learn more about the virus-mite complex (this is a K-12 educational video): Click here to open video.