Scarlet Tiger Moth

This afternoon I saw a Marbled White butterfly land on the Spirea.  It's the first one I have seen this year - one of the first butterflies of any sort, other than Speckled Woods and Brimstones, that I have seen this year.  By the time I got my camera it had flown away into the woods.  But, close to where it had been, was a Scarlet Tiger Moth which gorged itself for ages on the Spirea flowers.  This is the underside of the hindwing, a burnt orange colour.  The top of the hindwings are bright scarlet, but completely covered by the black & white forewings when the wings are closed.