About Eudonia mercurella Linnaeus, 1758
This species, Eudonia mercurella, has a wingspan ranging from 16 to 19 millimeters (0.63 to 0.75 inches). Its forewings are a dark black base color variably mixed with brown, with a darker band running along the distal edge of the pale antemedian line. The pale postmedian line is typically clearly visible against the dark base color of the wings. Eudonia mercurella is similar in appearance to Eudonia lacustrata; Eudonia lacustrata can be distinguished by its broken wavy line that forms a broad white spot at the apex, or tip, of the wing. An additional distinguishing feature found in female Eudonia mercurella is the ventrodistal hump of the valvae. Eudonia mercurella also resembles Eudonia speideli in external appearance, as well as pale specimens of Eudonia liebmani.
