Beech Blight Aphids

These aphids look like snow on a branch. They are not going to kill this tree, although they do enjoy the sap underneath the bark. Their excretions feed a large yellowish fungus or mushroom on the ground below them. Also, a nest of yellow jackets seem to be happy there. I found another tree further away in another part of the woods, with the same aphids, and the same fungus, and the yellow jackets as well, so I guess they all go together. The aphids wriggle and move in a sort of dance. Very interesting.