Most gall insect species lay their eggs in plant tissue, and feeding by their larvae produces a wide variety of galls.
Vein pocket galls are hard, tan-colored rolls or tube swellings along the midrib and major veins and leaf margins of oak trees.
Controlling gall insects is difficult, as there are no insecticides registered for this use by homeowners. Early treatment is necessary because any insecticide applied after galls are already present is useless. Galls will not go away even if the parasite is killed. Fortunately, the vast majority of galls are not particularly injurious and are of no economic significance. Pruning out heavily galled portions of a plant is sometimes possible and may help reduce populations of the gall insects.