Scientific name: Gonepteryx rhamni
The Brimstone is a medium-large butterfly of England, Wales and Ireland. When it roosts among foliage, the angular shape and strong veining of its wings closely resemble leaves.
There is a view that the word 'butterfly' originates from the yellow colour of male Brimstones. The wings of the female are very pale green, almost white, while males have yellow-green underwings and yellow upperwings.
The Brimstone can be seen widely most of the year as an adult butterfly. It is single-brooded and hibernates as a butterfly in the winter in ivy, holly and bramble, re-emerging on warm spring days.
The egg is bottle-shaped and laid singly underneath young Buckthorn leaves. When the egg has just been laid, it is a very pale green, but, as the caterpillar grows inside, it turns pale yellow then grey.
The caterpillar emerges around the end of May and, although its blueish green body with a white stripe camouflages it well, it can be easily found on Buckthorn due to the damage it causes to the leaves. It rests with its front half lifted off the leaf and moults four times during this stage of its lifecycle (for around a month).
The chrysalis is green with purple markings and shaped like a curled up leaf, so can be hard to find. It pupates away from its foodplant on nearby vegetation, attaching itself by the tail with silk to a stick, branch or plantstem, supporting itself with a silken girdle. This stage lasts around two weeks.
The Brimstone has spread in recent years, mainly in northern England.
Size and Family
- Family: Whites and Yellows
- Size: Large
- Wing Span Range (male to female): 60mm
- Butterfly Conservation Priority: Low
- Europan Status: Not threatened
- Fully protected under the Northern Ireland 1985 Wildlife Order
The larvae feed on leaves of Buckthorn (Rhamnus cathartica), which occurs mainly on calcareous soils, and Alder Buckthorn (Frangula alnus), which is found on moist acid soils and wetlands.
The Brimstone can be found in scrubby grassland, woodland, gardens and wasteground. The larval foodplant (Buckthorn) occurs in woodland, scrub and hedgerows. The butterfly ranges widely and can often be seen flying along roadside verges.
- Countries: England, Scotland, Wales, and Ireland
- Common in England and Wales, less common in Ireland and very rare in Scotland
- Distribution Trend Since 1970’s = -43%.