The brimstone (Gonepteryx rhamni) is one of the first butterflies early in spring. Its name comes from its yellow color similar to sulphur. Its wing shape is unique to act as camouflage and it never settles with its wings open. In the picture here the upper side is visible thanks to a shooting at the very moment it escapes from a Violette.
It is a male because the upper side is yellow while the female is white with a greenish tinge, but both have an orange spot in the center of each wing.
It lives in Europe, except in the extreme north, in North Africa and in Asia. In many of European countries, its common name refers to its color too but compared to lemon, papillon Citron in French, Zitronenfalter in German, Citroenvlinder in Dutch and Listkowiec cytrynek in Polish.
It is one of the longest lived butterflies, living up to thirteen months, although most of this time is spent in hibernation (outdoor contrary to most butterflies in that case). The brimstone usually hides until early spring, although a warm January day will occasionally wake an eager male.
The name "butterfly" is believed to have originated from the brimstone which was called the butter-coloured fly by early British naturalists.