The lesser broad-bordered yellow underwing or Langmaid's yellow underwing (Noctua janthina) is a moth of the family Noctuidae.

Like other members of its genus this species has bright orange-yellow hindwings but as the common name suggests the black sub-terminal bands are very broad and account for about half the area of the hindwings.

See Townsend et al.[1] The adults fly at night from the latter half of July to August[2] and are attracted to light and sugar.

The larva is brown with v-shaped markings along the back.

It feeds on a wide variety of plants (see list below).