The little pimples are called galls and are caused by the feeding of small mites. The gall-making insect or mite develops within the plant gall. The gall continues to expand as the gall maker feeds. Once formed, galls may remain on the plant for long periods, even though the insect may leave it shortly after the gall develops. Many galls are not seen until after the insect or mite leaves the gall. Although galls are conspicuous and unattractive, they rarely do any real damage to plants. Gall-making is cyclical and problems often subside on their own. Furthermore, once galls start, formation is largely irreversible. Under most circumstances, control is not possible, nor is it recommended. |