To see one, look in scrubby grassland, woodland, gardens, wasteground and they can often even be seen flying along roadside verges.
The Brimstone (Gonepteryx rhamni) gets its name from the old word for the element, sulphur, which is also yellow. It’s even thought that their colour put the word butter into butterflies! Males are a bright yellow, while females are a paler greeny yellow.
They are one of the first butterflies to be seen in the year because they spend the winter as adults hibernating in ivy, holly and bramble and so are ready to come out on warm spring days. It one of the world’s longest-lived species of butterfly.