Dryocosmus quercuspalustris

The ball-like Roly-Poly galls, produced under the direction of the gall wasp, Dryocosmus quercuspalustris (family Cynipidae), are one of the most unusual galls found on oaks in Ohio. The hollow galls are around 1/2" in diameter and reflect the colors of newly expanding leaves. Indeed, the gall-wasps hijack leaf tissue to form their galls.

One of the most unusual galls found on oaks is the light green, ball-like Roly-Poly Galls produced under the direction of the gall wasp, Dryocosmus quercuspalustris (family Cynipidae). The specific epithet reveals one of the most common hosts of this gall-making wasp: Quercus palustris is the scientific name for Swamp Spanish Oak (a.k.a. Pin Oak) with palustris being Latin for “swampy” or “marshy.”