As I was inspecting the edge of my garden, I noticed something hanging from the tip of a red oak leaf. I had never seen anything like it before. What is it?
I entered a simple internet search, “what is a green ball hanging from an oak leaf,” and was rewarded with a host of answers. What I had seen is a gall, produced during the life cycle process of the Oak Apple Gall Wasp (Amphibolips confluenta). I have seen galls on other oaks in the woods, but they were much smaller and harder than this soft, golf ball sized growth. This one has grown rather quickly; the oak only leafed out about three weeks ago.
In the interest of science I cut the gall in half to see what was inside. The developing larva can be seen at right. I elected not to dig further.
Numerous sources described the life cycle of the Oak Apple Gall Wasp and confirmed this identity. There is no reported evidence that it is harmful to its oak host. It serves as a food source for birds, most notably Downy Woodpeckers and Carolina Chickadees, both of which we have in abundance flitting about our garden.
And so I have learned something new. The garden once again has proved itself to be a wonderful learning laboratory (backed of course by an internet search engine).