This little moth goes by the very fanciful common name of The Purple Plagodis. To me, it sounds like an architectural feature of some kind. Imagine the description of the trim on an old Victorian house - a profusion of white scrollwork detail, topped with a purple plagodis. Doesn't that sound appropriate?
Here's the real thing - not quite so grand as its name might suggest, but still a lovely species.
The larvae feed on ash trees, which are abundant in this area.