The larvae feed on Vaccinium myrtillus, Vaccinium uliginosum and Vaccinium vitis-idaea. They make a blotch mine, then cut the mined part out of the leaf and use it to make the first case. Later, another (or rarely more) mines are excised to enlarge the case. The final case is a composite leaf case of 8–14 mm long. It is brown or blackish. The mouth angle is 40-55° and the rim of the mouth is somewhat flared. Larvae can be found from July to autumn. Hibernation takes place in the case and pupation takes place shortly after winter.