Common in broad-leaved woodland, especially mature oak woods, parks, hedgerows and gardens throughout the British Isles; still widespread and common in Hampshire and on the Isle of Wight. Wingspan 42-52 mm. Similar in general appearance to Scarce Merveille du Jour Moma alpium
, but flies much later in the year, and is less heavily marked with black. Larva feeds on flowers and leaves of Oak, over-wintering as an egg; in spring the larvae can be found by day, wedged into crevices in the bark of old oak trees.