The Maiden's Blush moth has a reddish hue and a bold red line. It has a more flecked background and wavy red line than the larger Blood-vein moth, with a black-bordered edge. Wingspan: 18-25 mm; UK flight time: May-Aug.

 

The Blood-vein moth has a yellowish background flecked with grey like the Maiden's Blush and also a bold red line. Wingspan: 23-28 mm; UK flight time: May-Sep (2 generations).
Instead of the two rows of black dots it has a lower grey wavy line; the bold red line is straight, forming either a straight line or slight V when the moth is at rest and the lower edge is continuous crimson/pink rather than broken black.

The Small Blood-vein moth can be browner (less pink) than shown and has a much wider, browner line across the wings. Wingspan: 26-29 mm (slightly larger than the Blood-vein Moth!); UK flight time: Jul-Sep.