The Scarce Silver Y (Syngrapha interrogationis) is a moth of the Noctuidae family.
It is found in the Northern areas of the world, from Alaska, through Canada, Iceland, Europe, Sibiria up to North-east Asia. It is common in areas of northern Britain but is a rare immigrant to the south of the UK. The photo shows a specimen trapped in Surrey (where it was the 4th ever record). It is probably of a continental European origin.
The wingspan is 32–38 mm. The moth flies from June to August depending on the location.