The Treble-bar moth, one of the largest Geometrid moths, is very similar to the Lesser Treble-bar (see below).
Caterpillars live on St John's Wort, giving the moth its alternative name of St John's Wort Inchworm.
Wingspan 37-43mm; UK flight time May-Sep.
The Lesser Treble-bar moth is very similar to the Treble-bar, but the first brown bar nearest the head is angular rather than roundly curved.
If the two moths are side by side, then other minor differences may be apparent: slightly smaller size, slightly paler background, male has less pointed body.
Wingspan 35-41mm; UK flight time May-Sep. Often disturbed during the day but flies from dusk to after dark.
Photo on left in UK by Liz Barrett; photo on right in Kazakhstan by Alexandra Makhnina