Willow Gall

Willow Pinecone Galls are the work of the so-called Willow Pinecone Gall Midge. They house, nourish, and protect a single fly larva (maggot) located deep within the gall. There is a single generation per year.

I received an email message this past weekend from Brad McBride (The Davey Tree Expert Co.) alerting me that Willow Pinecone Galls are reaching their full glory on their namesake host near the Everett Covered Bridge in the Cuyahoga Valley National Park. It’s certainly worth a visit to enjoy this picturesque wonder, and perhaps look at the bridge too.

Willow Pinecone Galls, with their faux seed scales, bear a striking resemblance to pine cones, particularly when the galls darken during the winter. The galls are induced by the so-called Willow Pinecone Gall Midge, Rabdophaga strobiloides (family Cecidomyiidae), to house, nourish, and protect a single fly larva (maggot) located deep within the gall.

Willow Pinecone Galls, with their faux seed scales, bear a striking resemblance to pine cones, particularly when the galls darken during the winter. Of course, pine cones don’t occur on angiosperms, only on gymnosperms. And, a close examination will expose the pine cone ruse with the galls covered in fine hairs; pine cones aren’t hairy.

Willow Pinecone Galls are produced by the Willow Pinecone Gall Midge, Rabdophaga strobiloides (family Cecidomyiidae), to house, nourish, and protect a single fly larva (maggot) located deep within the gall. The elaborate structures bear a striking resemblance to a pine cone complete with faux seed scales.

Willow Pinecone Galls are one of the most unusual galls found in Ohio; I post a BYGL Alert! about them every year. Maybe more than one to spread the gall-joy! The galls are created by the Willow Pinecone Gall Midge to house, nourish, and protect a single fly larva (maggot) located deep within the gall. The literature lists a number of willow hosts; however, I've only ever found them on black willow.