Wingspan 11-13 mm.
Another nondescript species, which is most easily identified as an adult by reference to the genitalic structure.
The larva produces a distinctive feeding pattern, creating small holes in the leaves of the foodplant, evergreen oak (Quercus spp.). A case is then created which is replaced as the larva grows.
Distributed widely but locally throughout most of Britain and southern Ireland, the adults appear in July and August and are attracted to light.