Description: The grape leaf underside, displaying the indentations caused by the Grape Erineum Mite. We found little damage resulting from mites for several years. They appeared on several leaves and did not pose a problem. This year we had a major infestation and treated with insecticidal soap. We sprayed once and ninety nine percent of the mites were killed. The second spray in seven days took care of the problem. Make sure to spray both the top and bottom of the leaves.