Photo © Gail Hampshire
Archiearis notha, the light orange underwing, is a moth of the family Geometridae. The species was first described by Jacob Hubner in 1803 and can be found in Europe.
The wingspan is about 35 mm. The moths fly from March to April depending on the location.
The larvae feed on aspen (Populus tremula), hiding between spun leaves during the day.
Source: Wikipedia
The primary larval foodplants are Aspen (Populus tremula) and willows (Salix spp.).