Gall
insect-induced growth on plant. often very distinctive and even species-specific structures developed when insects, fungi or bacteria stimulate abnormal growth of a plant / From Wikipedia, the free encyclopedia
A gall is a growth on the surface of plants and other lifeforms. They are caused by various parasites, such as fungi, bacteria, insects and mites.
Plant galls are abnormal growths of plant tissues similar to benign tumors or warts in animals.[1]
What causes a plant gall can often be known without the actual agent being there. Many types of gall have typical structures. This is true of many galls produced by insects and mites.
Insect galls on plants give some herbivorous insects their own microhabitat. They are plant tissue which is controlled by the insect. Galls are the habitat and food source for the maker of the gall. The gall may contain nutritious starch and other tissues.[2] Galls often give the insect physical protection from predators.[3][4]
Insect galls are usually induced by chemicals injected by the larvae or the adults of the insects into the plants. After the galls are formed, the larvae develop inside until fully grown, when they leave. In order to form galls, the insects must seize the time when plant cell division occurs quickly. The growing season, spring in temperate climates, is longer in the tropics.