August Thorn Ennomos quercinaria
Wingspan 42-50 mm.
One of several similar 'Thorns', the adults of this species can be distinguished by the shape of the cross-lines on the forewing. The inner line is distincly curved, and the outer line has a 'kink' where it meets the leading edge.
Flying in August and September, the species is often attracted to light. The foodplants are trees such as oak (Quercus) and beech (Fagus).
It inhabits woodland and suburban habitats, and can be found locally throughout most of Britain.