A common moth throughout Britain but becoming scarce towards the north-west of Scotland. Morphologically variable, which can cause confusion with other species. The flight period for Britain is May-October but probably shorter in the Outer Hebrides. A notorious pest of brassicas, it also feeds on the leaves of numerous herbaceous plants, cultivated and wild.

References: 
Leverton, R. & Cubitt, M. (2024). The Larger Moths of Scotland.
Waring, P. & Townsend, M. (2018 third edition). Field Guide to the Moths of Great Britain and Ireland.