Hiker's Guide to the Trees, Shrubs
and Vines of Ricketts Glen State Park
Oak Bullet Gall, Caused by the Wasp
Dryocosmus imbricariae
(Hymenoptera: Cynipidae)
Identification by Dr. Carol Mapes, Biology Dept., Kutztown Univeristy of PA.
Updated 28 September 2018.