Infected spring wheat or barley plants are stunted, with mottled green-yellow streaked leaves. The streaks are parallel and discontinuous. Leaves and sometimes entire plants may become yellow and necrotic. Stunting and yellowing become more obvious as spring temperatures rise. The mite vector prefers to feed on the upper surface and near the margin of leaves.
Mites feeding near the leaf margins causes the leaves to curl upward and toward the midvein.
Crop injury from WSMV can be confused with injury symptoms of imidazolinone and sulfonylurea herbicide families. See photo 44. 44 Plants infected with WSMV have green and yellow streaks that run parallel and are discontinuous on the leaf. Healthy leaf appears at the bottom.