Tuleyome Tales: Nope. They're not apples or urchins. They're wasp galls
Minnesota Seasons - spongy oak apple gall wasp
Oak Apple Wasp Galls | BYGL
Oak apple - Wikipedia
How Wasps Make Beautiful and Complex “Oak Apples” | Brandywine Conservancy and Museum of Art
Oak Galls
Gall wasp | insect | Britannica
The Real Dirt Blog - Agriculture and Natural Resources Blogs
Oak Apple Wasp Galls | BYGL
What Are Oak Tree Galls?
Oak marble gall wasp | The Wildlife Trusts
Gall wasp - Wikipedia
Do you know what galls me? Cynipid wasps | OSU Extension Service
Oak Galls and Gall Wasps – Hiker's Notebook
Oak Bulletgalls are Rising | BYGL
Gouty, horned and other twig galls
CAMPUS BIODIVERSITY: Oak Gall Wasps
Gall wasp, an insect that parasites trees and plants – types and treatment
Galls on the Valley Oaks of Effie Yeaw | Effie Yeaw Nature Center
Gall wasp, an insect that parasites trees and plants – types and treatment
What Gall! The Crazy Cribs of Parasitic Wasps | KQED
Oak Gall Wasp | From the Ground Up - YouTube
