...and it's a female, which makes it harder to ID by genitalia because all the distinctions in Braun's key are relative rather than absolute. I'll try some of the others reared from Q. virginiana a little later, and hopefully there are some males, but C. simulata seems to be the best match at this point. If this is a described species, C. concolor and C. clemensella would be the only other candidates based on the mine type, and the genitalia rule those out. The way the mine consistently starts at the midrib seems odd for any of these three, so it may well be an undescribed species.

Thanks for the update... I'll see if I can find more this spring. I feel like there have been at least a few adults over the years, but I am not sure how many offhand, or if we have enough to describe a species if it turns out to be new.