Notch-wing Button

Acleris emargana has a wingspan of 18–22 mm. Appearance can vary between individuals within the species. In general, the forewings are greyish brown or yellow ochreous, lightly translucent, usually more or less notched and hooked on the costa, with a reticulated (net-like) pattern. Hindwings are greyish and translucent. Julius von Kennel provides a full description. Very similar to and much confused with Acleris effractana. The moths are on wing from July to November and fly at dusk. The larvae can reach a length of about 15 mm. They are pale green, with a pale brown head. Caterpillars feed on the leaves and shoots of various trees, including Alnus glutinosa, Corylus, Salix, Populus and Betula.

The nominotypical subspecies Acleris emargana emargana is found from Europe to Siberia, northern China, Korea and Japan. In Tibet, ssp. Acleris emargana tibetica is found.