Last year I caught my first Merveille du Jour on 30th September. One day later this year I had the pleasure of seeing my second “marvel of the day”. The species spends the winter as an egg in crevices on its foodplant- Pendunculate Oak. When the egg hatches in the spring the larvae feed in opening buds, feeding only by night when it grows larger, and hiding in bark crevices during the day. When fully grown it makes a cocooon undergound and emerges as the adult moth in the autumn.