This type of feeding damage can appear in the spring on corn seedlings or wheat. A different insect is involved for each crop. The symptoms are long, narrow stripes which look like scratches on the leaves. The insect chews only part way throught the leaf, leaving a thin strip of tissue which soon dries and turns brown. Severe feeding damage can turn entire leaves brown, as if they had all of the chlorphyll scraped off the leaves.
This damage is most severe after mild winters, and during cold, wet periods when plants are growing slowly. This feeding damage generally is not severe enought to kill the plant.