Backyard and Beyond

I found a mother-of-gall tree! A red oak, Quercus rubra, in Green-Wood. This tree was probably brought in as a sapling a few years ago. I wonder where it was raised? Could it be that the gall-making species came in with the tree, as we’ve seen with lichens transported into the city on saplings destined to be street trees?
Everything pictured in today’s post was on this one oak — two very nearby red oaks, both looking like they were planted this year or last, were devoid of this diversity. They only had one type of gall on them.
How many gall-makers are seen here? Three, four?
Is this, for instance, one or two gall species at work?
Oops, here’s another.
And another.

Getting very little traction on iNaturalist with identification for these things. There are too many galls and not enough people interested in them.

And yet, consider the fascinating relationships of insect (wasp, mite) and plant. (And not just insects!) The plant forms these structures, which are unlike anything else they produce in the normal course of events, in response to the animal. The animal uses the plant for shelter and food, and some other animals may use the first animal, parasitizing the egg or larva inside the gall. And around and around it goes.