Gills are known as a series of tumor-like structures induced by various animals, among which insects and other arthropods, nematodes, fungi, bacteria, among others, can be mentioned. It is a response of the plant due to the presence of the parasite with an abnormal growth in the tissue that tries to isolate the attack of the external agent. The tissue that is formed takes on very different forms. In the case of galls that occur in oaks, which is produced by the hymenopteran cynipids, they have a peculiarity and it is the alternating generations of these insects.
In the autumn season the agamo lays its eggs in the new shoots and in the yolks, producing the small galls during the winter season; while the next generation is born in the months of April to May.
In the case of trees, the galls are like extrusions that hang down as if they were fruits; in fact, these are called oak apples and originate after the wasps lay their eggs in the bark of the tree. These structures have high values of tannic acid and for a long time have been used to manufacture drugs in many regions of the planet.
Despite the fact that all oak galls are presented by the action of the so-called gall wasp, all of these can be highly variable in shape, color and size. For their part, the larvae of this species force the oak to create substances and cells that produce galls, which at the same time are used by the former as a source of food and as a refuge. It is important to point out that they generally do not represent a danger to the tree, even though their formation is an act of defense on their part, which explains their high content of astringent elements.
