Galls are an abnormal swelling of plant tissue and can be caused by mites, insects, nematodes, bacteria or fungi. Galls usually are found on leaves and stems, but can sometimes be found on other locations of the plant. In this case, the organism causing the oak leaf gall is a wasp. The gall grows around the insect and helps to protect it from predators and weather. The gall will also provide nutrients to the wasp until the wasp is fully mature. The galls do not seriously affect the… Read More →