What are Galls?
A gall is any unusual growth of plant cells which have been stimulated by chemicals secreted or injected by an insect, mite, nematode or disease agent. As an example, gall wasps insert an egg into developing plant tissues, and at the same time, it injects some chemicals formed in its body. The chemicals stimulate the plant cells into a rapid and abnormal division and growth of plant cells in the immediate vicinity of the egg. The egg, as it hatches and continues developing into a larva that also secretes fluids from its body cells. Thus, the surrounding plant tissue continues to grow abnormally into a characteristically shaped gall. The size, shape, and form of the gall is determined by the gallmaker, and also by the plant it selects. The galls are always identical for each gallmaker, season after season. There are, in general, two types of galls – open and closed. Open galls are produced by insects with sucking mouthparts and mites. The gall always has a hole, slit or other opening wh
