Wingspan 8-12 mm.
The eggs of this species are laid on the underside of leaves of alder, hazel, birch or hornbeam.
The larva creates its case from a portion of the leaf, and then attaches to the underside of the leaf, with the larva mining the leaf from beneath. The larvae overwinter in the case attached to a leaf or twig.
The adults emerge in late June or July and are widespread in woodland where the foodplants are found.