Gall

(5.28.17) wooly oak gall 1

I recently met a Facebook friend in real life for the first time, and one of the subjects that came up in conversation was our respective blogs. “So you’re a trained naturalist?” she asked. I had to confess that I’m actually more of a Googler, and not even a trained one.

It took a lot of nerve for someone as fundamentally ignorant of nature as I am to start a nature blog, but one of the nice side effects of ignorance is constant astonishment. A few weeks ago, I was standing at the window with my camera, using the zoom lens to search for a house wren that I could hear but couldn’t see, when I noticed something odd on a branch of the oak tree that grows just outside the window.

It was a white, spongy pod, about the size of a golf ball, protruding from the tip of a tiny branch. I had no idea what it was. A cancerous growth? A cocoon? The seed pod of a parasitic plant? And how would one even Google such a thing?

“White ball on the end of an oak branch” finally turned up an image that matched what was happening on my own oak tree, and I learned that the puffy-looking growth is called an oak gall. Many different kinds of galls can form on oak trees, but this one was made by the wool sower gall wasp, a small black insect that lays its eggs in winter at the tender ends of young branches. The eggs hatch in springtime, just as the twig begins to put on new growth, and the tiny larvae produce a chemical secretion in their saliva that forces the tree to form a gall. The gall then serves as a nourishing, protective case for them until they are ready to crawl out of their woolly home and take to the air.

The transformation of any sort of grub into any sort of winged being is a metamorphosis that can’t possibly fail to fascinate, so I checked on the woolly gall every day, hoping to catch the very moment when the tiny wasps emerged into the light of springtime.

But the oak was not ready to surrender its own purposes for spring: instead of wool sower gall wasps, what emerged from the gall was a pair of strange-looking, apparently-dwarfed oak leaves:

(5.28.17) wooly oak gall 2

And then the dwarf leaves began to stretch out languidly, not unlike a typical oak leaf. Meanwhile the gall was taking on the definite appearance of something pregnant with an alien life form, and it was something alien that fully intended to hatch:

(5.28.17) wooly oak gall 3

I don’t know when the gall formed, but tomorrow will mark five weeks since I discovered it, and so far I have seen no sign of the miniature wasps. It’s impossible to say if that’s because I simply missed their hatching, or if they’re still inside the gall, waiting for their moment to emerge. I will keep watching, just in case, but as with all other things in nature, I entered this story in medias res, unaware of its beginning and given no promise of its resolution. All I can do in the moment is marvel.