The Rustic Shoulder-knot (Apamea sordens) is a moth of the family Noctuidae. It is distributed throughout the Palearctic ecozone (Europe, Russia, Turkey, Afghanistan, Tibet, Siberia, Yunnan, Amur, Russian Far East, Sakhalin, Japan) and is also found in North America.
This species has a wingspan of 36–42 mm. The forewings are brown with mostly indistinct markings except for a narrow but distinctive black mark at the very base of the wing which gives the species its common name. The hindwings are greyish brown, darker towards the margin, with prominently dark venation. This moth flies at night in May and June  and is attracted to light and sugar.
Recorded food plants
- Avena - Oat
- Hordeum - Barley
- Secale - Rye
- Triticum - Wheat
- Zea - Maize
Fields, grasslands, steppe.
- Chinery, Michael Collins Guide to the Insects of Britain and Western Europe 1986 (Reprinted 1991)
- Skinner, Bernard Colour Identification Guide to Moths of the British Isles 1984