In very sensitive lettuce varieties, there may be browning of the veins or on the edges of the leaves. The leaves may die. Leaf margins may become ruffled and distorted, and the leaf tips roll back. This downward curling of the leaf tips can be diagnostic in older plants of the crisphead variety. When plants are older, the yellow green mottling may be difficult to see, although it may be visible on the edges of the leaves.
Plants are often a uniform dull pale green to slightly yellow and severely stunted.
Outer leaf tips roll downward. The serrations of the younger leaves may be particularly prominent. The plants appear flatter than healthy plants. They may fail to head, produce a small, loose head or, if infected later, may produce a deformed head. This disease is transmitted by the green peach aphid in a nonpersistent manner.