Square-spotted Clay Xestia stigmatica
Wingspan 37-44 mm.
A local and elusive species, with a scattered distribution mainly in the south of England, but also with some localities in northern England, Wales and Scotland.
Inhabiting deciduous woodland with scattered undergrowth, the adults fly during August.
The caterpillar has only recently been found in Britain for the first time in the wild. The actual foodplants are not yet fully understood, but are probably a variety of plants such as bramble (Rubus fruticosus) and birch (Betula).