Wingspan 18 to 22 mm. The notched and hooked forewings of this species create a very distinctive outline, but the colouration is variable and the depth of the costal emargination varies.

Acleris effractana

Acleris effractana is a predominantly Northern/Scottish species, which was formerly considered a form of Acleris emargana. Where any individual has distinctly shallow costal emargination and is a generally plainer grey form, then dissection is preferable. All VC55 dissections have confirmed A. emargana, and there are no National records of A. effractana as yet to suggest that it occurs in VC55.

Around the larval foodplants.

Flying from July to September.

The larvae feed on the leaves and shoots of trees such as Willow, Poplar and Birch.

The species is commonest in the south of Britain, becoming less common further north. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as common.

Fairly frequent, though not really common, in Leicestershire and Rutland.