Pebble Hook-tip Drepana falcataria
Wingspan 27-35 mm.
The largest and commonest of the 'hook-tips', found over most of Britain except on the highest ground, occupying woodland, gardens, heathland and similar habitats.
The adults fly at night from May to June and have a second brood in August.
The larvae feed usually on birch (Betula), but sometimes on alder (Alnus glutinosa)