Mrs Sciencebase spotted this fellow roosting in the garden last night…it was the moth that was roosting, not Mrs Sb. It’s a Purple Thorn. So-called because the larva (caterpillar), which is stick-like in appearance has a spiky projection and the adult has a purple hue to its wings.
Its scientific name (binomial) is Selenia tetralunaria. It has four white crescent moon shapes on its wings, hence the tetralunaria of its binomial. Selenia is the genus and there are a couple of dozen of this type of moth around the world, a fraction of the 180,000 different known moths (and butterflies, same thing)