Oak Apple Gall

The oak apple gall is caused by a wasp (Amphibolips confluenta) that lays an egg on the center rib of a budding oak leaf. The egg hatches and the larva's saliva causes the leaf to mutate and form a ball around the larva (top photo). The larva eats from the mutated leaf and then hatches in mid-summer. The middle photo shows the gall cut open, with the fine lacing that holds the larva inside. In the bottom photo I extracted the center of the gall and cut it open, to show the wasp larva. (I said a prayer to the wasp gods, asking forgiveness for killing an innocent larva.) (Click to enlarge.)