Confidence: I'm as sure as I can be.
Notes: As suggested, one of the Yponomeuta ermines. Thistle Ermine doesn't have the obvious spots behind the head as shown in the picture above.
The angle of the picture doesn't allow ID to species level, as the whole pattern of spots on the wing needs to be seen. Adult padella and malinellus can't be safely separated anyway. To go further with this group, there are some very good comparison pictures here: