Coleophora ibipennella:
I visited Marthall SJ7875 on 12th November 2011 and spent the day leaf-mining in the area. On the first oak tree I looked at was this case of Coleophora ibipennella. The larva produces a characteristic window feeding pattern which may be an easier way of locating the larval case.
The status of this species in Cheshire is unclear as there has been confusion between this species and the birch feeding Coleophora betulella.
Steve