Adults of the lesser yellow underwing moth have pale brown camouflaged forewings and bright yellow-orange hindwings with hooked, dark border markings. They fly from July to September.
The smooth greyish caterpillars appear from September to October, hibernate and then reappear between April and June, and they have darker flecked markings. This species is common and widely distributed.
Recorded in 69 (100%) of 69 10k Squares.
First Recorded in 1834.
Last Recorded in 2020.