The common brimstone (Gonepteryx rhamni) is a harbinger of spring, just like the coltsfoot and the singing of Eurasian chaffinches. It takes wing in early spring. The females are light green, while the males are lemon yellow.
The common brimstone is a skilled flier and can wander far way from its breeding sites. The female lays its eggs one at a time on alder buckthorn leaves. The caterpillars pupate one month after hatching. By mid-July, a new generation of butterflies is already flying around. Common brimstones winter on the ground, among leaves or brushes.