Round-winged Muslin Thumatha senex
Wingspan 15-20 mm.
The sparsely scaled wings of this moth give it a thin, papery appearance.
Distributed widely, though not commonly, throughout a large part of Britain, it is scarcer in Scotland and Ireland, and inhabits marshes and fenland.
The adults fly in July and August, and are attracted by light.
The larvae feed on lichens, especially dog lichen (Peltigera canina), as well as various mosses.