Callirhytis balanacea
Quercus imbricaria, palustris, phellos, rubra, velutina
Acorn galls
A pip gall in the fall beside small acorns of current season, spherical, up to 6.3 mm, smooth, bare, secreting honeydew, dropping in Oct and turning black.
[Photo caption]
On Q palustris. Also on Q velutina, phellos. Outer layer turns black, wrinkles, dries down on the hard inner shell (photo), drops Oct 12 (DC); adults emerged the second spring Mar 26-Apr 2 and the third spring in April.
- LH Weld: (1959) Cynipid galls of the eastern United States©
Reference: https://www.biodiversitylibrary.org/item/273718#page/110/mode/1up