The wingspan is 35–38 mm. The length of the forewings is 16–20 mm. Has no pale grey tints; the red-brown ground colour varying only to dark grey; the claviform (club-shaped) stigma is produced as a dark dash to outer line; upper stigmata pale with partial black outlines, a black basal streak with pale patch above it; hindwing pale fuscous, paler at base; the form achates Hbn. has the forewing uniform red brown; while humeralis Haw. is fuscous grey with the red tints absent; ab. nigrifusa nov. [Warren] is wholly suffused with black, the orbicular stigma and traces of outer and submarginal lines remaining pale grey.[2]
The moth flies in two generations from early May to September[1].
Larva green or reddish yellow, with two dark oblique stripes on each segment, with two dark spots or blotches in front of them; lateral lines pale grey with red edges. The larvae feed on various deciduous trees and plants: Betula sp., Alnus incana, Salix sp., Polygonum spp., Chenopodium album, Delphinium sp., Berberis sp., Brassica spp., Rubus idaeus, Sorbus aucuparia, Pisum sativum.[5]
Found in very different habitats - forest, meadow, heath and moorland areas as well as in urban gardens and parks. In the mountains, it rises to an altitude of about 1600 meters.
Notes
^The flight season refers to Belgium and The Netherlands. This may vary in other parts of the range.
^Seitz, A. Ed., 1914 Die Großschmetterlinge der Erde, Verlag Alfred Kernen, Stuttgart Band 3: Abt. 1, Die Großschmetterlinge des palaearktischen Faunengebietes, Die palaearktischen eulenartigen Nachtfalter, 1914
^Hermann Hacker, László Ronkay & Márton Hreblay: Noctuidae Europaeae, Volume 4, Hadeninae I, Entomological Press, Søro 2002, ISBN 87-89430-07-7, S. 61/62
^Walter Forster, Theodor A. Wohlfahrt: Die Schmetterlinge Mitteleuropas, Band 4, Eulen (Noctuidae)., Franckh’sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5, S. 74
