Wool Sower Gall - Callirhytis seminator
These were the prettiest galls that I've ever seen!
They were fluffy, white ball with pink spots and was about 4-5 cm across. One gall is actually a group of smaller, hairy galls that are joined at a common spot on a twig. They can be pulled apart to see seed-like structures that contain the developing wasps. I spotted 6 galls growing on Oak (Quercus sp.) - probably White Oak (Quercus alba).
Callirhytis seminator is a parasitoid wasp in the gall wasp family (Cynipidae) found in the eastern United States.