Dusky Hook-tip Drepana curvatula
Wingspan 34-42 mm.
This species is a very rare migrant to Britain, and has only been recorded on a dozen or so occasions, mainly attracted to light-traps on the south and east coast.
It is fairly well distributed in Europe, where it tends to fly with two overlapping generations, from May to July and from July to August.
A mainly woodland species, the foodplants are alder (Alnus glutinosa), oak (Quercus and birch (Betula). The larva has a distinctive stripy-headed appearance.