Little Thorn Cepphis advenaria
Wingspan 23-26 mm.
A day-flying species, which prefers sunshine, but will fly in dull weather if disturbed.
It is a woodland species, and occurs most frequently in some of the southern English counties, though it is quite local.
The adults are on the wing in May and June, and the larvae feed mainly on bilberry (Vaccinium myrtillus), but probably also on bramble (Rubus) and other low plants.