The Cape’s oak trees are under attack from the tiny oak gall wasp. The gall wasp is less than 1/16th of an inch long and resembles an amber drop of sap with eyes and a pair of wings. Most species of gall wasps live as gall-formers on oaks. One of the most well-known of these oak gall wasps is the common oak gall wasp (Cynips quercusfolii), which induces characteristic, 2-cm in diameter, spherical galls on the undersides of oak leaves. … Continue reading →