Lunar Thorn Selenia lunularia
Wingspan 38-44 mm.
This species is named after the 'lunar' or moon-shaped white mark on the wings, but more distinctive is the single deep scallop on the hindwing.
Locally distributed over much of Britain, it flies in May and June and comes to light.
The larvae, like those of most 'thorns', closely resemble twigs, and have perfect camouflage at rest. They feed on a range of deciduous trees such as oak (Quercus) and birch (Betula).