Nationally scarce (Nb) in dry sandy areas, heaths and open woodland, discontinuously in parts of Britain, greatly declined, a priority species under the UK Biodiversity Action Plan. In Hampshire there are strong colonies in the Test valley, at Porton Down and Cholderton, both on the Wiltshire/Hampshire border, and the moth is recorded occasionally elsewhere, but often erroneously. There have been no Isle of Wight reports since 1894. Wingspan 38-45 mm. Distinguished from
Lesser Yellow Underwing N. comes by its narrower forewing and straighter costa, and by the presence of a black mark towards the apex. Distinguished from small examples of
Large Yellow Underwing N. pronuba by the presence of a curved discal spot on the hindwing which gives this species its vernacular name.
Please note that no records of this species from new sites outside of established colonies at Cholderton and Porton Down will be accepted without photographic evidence of the hindwing
Larva feeds on various grasses and herbaceous plants, including Sheep's-fescue, Wavy Hair-grass, Cock's-foot, Common Couch, Reed Canary-grass, Meadow Buttercup, Creeping Cinquefoil, Cowslip and Chickweed.