Common brimstone butterfly

Common brimstone butterfly
Common brimstone butterfly

Written by Jeannie Swales

We’re all being encouraged to “turn Yorkshire yellow” this summer, as part of the celebrations for Le Grand Départ of the Tour de France in the county – so here’s a small contribution from Scarborough Museums Trust.

The common brimstone butterfly (Gonepteryx rhamni) is a widespread species in the county, but not always easy to see, despite the vibrant yellow colouring of the male – when it alights on something, it tends to fold its wings flat, rather than sunning itself with wings spread.

Which is when that elegant shape, with the exquisitely delicate points on all four wings (a shape, by the way, found in no other British butterfly) comes in useful – at rest, its pale underside closely resembles a leaf.

The vivid yellow of its topside, of course, explains the name – brimstone is an alternative name for sulphur, which is a bright yellow crystalline solid at room temperature. It’s believed that the generic term ‘butterfly’ may derive from this species – a corruption of ‘butter-coloured fly’. Only the males are this dazzling – the poor females are much paler.

This is often the first butterfly to be seen when the weather turns warmer in early spring, but it’s a long-lived species, so seen throughout the year.

And with April Fool’s Day looming, I was delighted to find a wonderful little story about a brimstone online at the Museum of Hoaxes (

In 1702, a butterfly collector called William Charlton declared that he had discovered a new species – a butterfly resembling a brimstone, but with large black spots on its upper wings and ‘blue moons’ on its lower wings. So convincing was his specimen that, in 1763, Swedish naturalist Carl Linnaeus – the man who developed the system of naming, ranking and classifying natural organisms that we still use today – confirmed it to be a new species and called it Papilio ecclipsis.

But in 1793, another noted entomologist examined it again, and discovered it was just a common-or-garden brimstone with painted-on spots. With splendid style, the keeper of national curiosities at the British Museum, Dr EW Gray, was so enraged by the deception that he ‘indignantly stamped the specimen to pieces’.

These brimstone butterflies are part of an extensive entomology collection, much of it dating from Victorian times, in the Scarborough Collections, the name given to all the museum objects and artwork owned by the borough and in the care of the charitable Scarborough Museums Trust. For further information, please contact collections manager Jennifer Dunne on or 01723 384510.

And for more information on how you can help to Turn Yorkshire Yellow: