Overwinters as a pupa, adults coming regularly to light.
Note Can be confused with Lesser Swallow Prominent. In this species the pale greyish-white wedge is thinner and less distinct and extends from the trailing corner of the forewing half way to the wing base. It is also generally larger.
Recorded in 105 (75%) of 140 10k Squares. First Recorded in 1834. Last Recorded in 2019. (Data up to end 2019) Additional Stats