Wingspan 10-13 mm.
The eggs of this species are laid on the leaves of oak (Quercus). When hatched, the larva at first mines the leaves in a gallery leading to a blotch. Subsequently the larva forms a succession of cones (usually three) by folding the tips of the leaves, and feeding within.
The adults are difficult to distinguish from the recently separated C. robustella, so care must be taken.
The flight period is from May to July, and the moths can sometimes be attracted to light.