DESCRIPTION: The galls that a mite-induced are found in the form of large, yellowish blisters that arise on the upper surface of the host tree.  The hollows that are found on the underside are lined with whitish or pale brown hairs and it is here where the mites live. DISTRIBUTION: Occasional throughout but frequent where the host tree is found.  HABITAT: Found on the leaves of Walnut (Juglans regia).