Common, especially in the southern islands. The flight period is from August to October near reed beds and water margins. Common reed (Phragmites australis) is the preferred food-plant of the larvae.

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.