These look like 0099 Stigmella quercipulchella as pictured in the species page. However, I'm getting a bit confused as to the differences between S. macrocarpae and S. quercipulchella. As far as I can see by comparing my images with the ones of the species pages, macrocarpae has a wide frass line that fills the mine and quercipulchella has a narrow frass line that leaves the sides of the mine showing as white. But some of the images on the quercipulchella page have wide frass lines. I have images of both in my files.