Lilac Beauty.
(Apeira syringaria)

Appropriately enough this Lilac Beauty was within five feet of our only Lilac tree.

Information:
Of course, the 'Lilac' part of the name refers to the lilac-coloured "smudges" near the leading edge of this otherwise mainly orange moth. There are three primarily distinctive features - first, a very visible thin dark brown line angling across the fore-wing; second, the pose-at-rest with the wings outspread and the fore-wing leading edge creased - like a stylized 'Z' and third, the slightly scalloped hindwing that has a curved row of black dots.
They have a fore-wing length of 19-22mm and fly June-July in selective open woodland locations, beneath the tree canopy and in forest or woodland rides.