My Collins Guide to the Insects indicates you have a Magpie Moth.
Until this week southern Britain has had a damp dull early summer, hardly saw the sun in June (which is our sunniest month of the year!) hence as you say Xanthippe, very few butterflies...just a succession of Red admirals...always welcome, the odd Brimstone and a few Great whites or cabbage whites as I've always known them.
The real show is when the Tortoiseshell butterflies arrive in September and swarm on the Buddleia
How about you people in far flung places, what butterflies do you see ?