White Oak Gall Wasp Complex
Note: None of these galls are injurious to the plant – they only present cosmetic issues.

✅ Identification: Spangle Galls 

• Common Name: Spangle gall

• Wasp Genus: Neuroterus (possibly N. quercusbaccarum or N. quercus-batatus)

• Host: White oak (Quercus alba)

• Form: Flat, disk-shaped galls attached to the underside of the leaf, often near veins.

• Appearance: Vividly patterned circular “roundels” — yellow to red or brownish, with a raised central dot or depression.

• Texture: Often velvety or fuzzy.

Location: North central Illinois. ~12-year old white oak
Photographer: Bruce Marlin

The wasp species responsible are part of a complex guild of cynipid gall inducers, all of which depend on Quercus alba for part of their life cycle.

Caterpillar frass on milkweed

Weevil girdling on Asclepias incarnata

Weevil girdle and stump / loss of stem and flower