Photo by D O'Brien

Brimstone  Gonepteryx rhamni (Linnaeus 1758 )  

 Family: Pieridae, subgroup Coliadinae (The Yellows) 

Photo  by Sarah Bradshaw

Photo  by  Tim Furness


 Common and becoming more widespread  and abundance determined by the presence  of one of its larval foodplants .  It is a strong , fast flying,  far ranging species that can turn up in almost every corner of our county.  However they do come together to form colonies often in woodlands where they will overwinter.   The species is not under threat.

ID tips 

Our only large yellow butterfly and similar in size to a Large White  and with same purposeful strong directional  flight.  It  spends little time fluttering unlike the other whites. Only the male is citrus yellow, the female being pale green but both sexes have a orange spot in the centre of both fore and hind wings which you can glimpse in flight.  Occasionlly you can glimpse the  characteristic points on each wing . However the main diagnostic feature  in flight is the  female is the palest shade of green while the large white a pale cream.

 When not in flight they always have there wings shut.  Both sexes have a pale green underside with realistic cryptic leaf like viening and even brown spots of leaf damage.  The head, antennae and eyes are a rich dark burgundy. Both hind and forewings have a characteristic point, like a leaf tip, and can literaly disappear in front of your eyes when it lands to rest beneath a leaf.  


The maps illustrate Purging Buckthorn preference for limestone along the Magnesiam limestone ridge, The tabular hills on teh south side of the North York moors and the  Craven  limestones on Inglebrough, Grassington and Bastow.  Alder buckthorn prefers the wetlands of the Humberhead levels.

Buckthorn is a rare plant but widespread which accounts for the Brimstones gypsy lifestyleAlder Buckthorn  is acid-loving, being found in damp, marshy areas or as an under-storey in open woodlands.  Sometimes associated with old woodlands where it  was grown to produce gunpowder charcoal.  Often confused  at the bud and young leaf stage  with alder  which also prefers the wet. It grows mainly as a shrub, only occasionally reaching as high as 5-7m (15-20ft)  and tolerates partial shade.  It has also been widely planted as part of new  hedgerow in the stewardship scheme and by local authorities, nature reserves biodiversity projects and wildlife trusts 

Purging Buckthorn thrives best on poor, dry, chalk and limestone soils.  It is thorny  and can be used in hedging but grows into a tree 3-10m (10-30ft) in height. It is found along woodland edges and in scrubby areas and hedgerows

Buckthorn ID Tips

                                 Common or Purging Buckthorn                                                                                  Alder Buckthorn                          

Common buckthorn leaves are hairless, have toothed edged and curved veins (left two) and leaves have a  pointed tip; while alder buckthorn leaves are glossy have  smooth edges and parallel veins and red/brown  petioles (right two) Alder buckthorn is also easily confused with young common alder  and share the hairy karki coloured shoot tips and also grow in the same habitat. Both species are often confused with Dogwood.

Conservation Gardening  Tips

 If you plant a young plant in your garden you are nearly guaranteed more regularly visits and the delight of watching the  eggs develop into caterpillars from April- Late July   


Abundance Scale =

The northern limit of the species in Britain lies mainly across Yorkshire and Cumbria, and into Northumberland, with the occasional very rare sighting into Southern Scotland in more recent years. 

Very mobile, hibernating resident.  One brood, with butterfly stage lasting up to 12 months (approx Jul/Jul). 

The majority of tetrad records represent single sightings of wanderers, whilst tetrad clusters indicate areas of foodplant availability where regular breeding takes place.  The Brimstone is a butterfly invariably seen one or two at a time and even in its hotspot areas, site counts (covering up to 1km square) are rarely above the 10/30 range.  The butterfly has been recorded in every month of the year and increasingly reported earlier (Feb/Mar) and later (Sept/Oct). 

2019 was an excellent year with numbers much higher than any in the past 10 years.  Good sites in Yorkshire where this species has been regularly seen over the past couple of years are North Cave Wetlands, Strensall Common , Brockadale , Bishop Wood , and Nosterfield Nature Reserve .

Life Cycle

Adults  spread widely so it is not surprising we see them but finding their rare foodplant necessitates constant searching.  After wintering in woodlands  males emerge first and  hunt for females.  Eggs are placed on leaf buds at the shoot tip and the underside of the youngest developing leaves of foodplant leaves .  At first blue through green and then later pale cream  bottle-shaped eggs are quite conspicious  and are only laid on Buckthorn species.  

Females will spend time testing the plant selecting those in  fairly good light and healthy and she will return many times  over the spring monthes into summer.   They tend to choose smaller plants away from others in an attempt to avoid predation by  particularly blue tits  who will home in bigger plants with more caterpillars. Mortality rates can be very high. 

Eggs are laid from April to July and hatch after about 10 days.  At first pale pale yellow larvae feed on the underside of the youngest leaves  but rapidly grow  and later instars are darker green larvae take around a month and 5 instars to mature and usually leave their buckthorn to pupate in low vegetation.  

Adult butterflies emerge after about 2 weeks and can remain active until the end of Sept or later, returning to their woodland  home then can re-emerge to take advantage of good conditions to build up reserves. In very hot years they rarely reappear unless nectar is abundant.  

The species shows a strong preference for purple flowers when nectaring, and its long proboscis is well-adapted to feeding on flowers like Teasel Dipsacus fullonum.  Brimstones often hibernate under evergreen leaves, especially Holly or Ivy.  They may 'test' the air on warmer winter days and visit ‘Pussy’ Willow catkins Salix sp or early Dandelions  in search of a top-up nectar feed.  

Photo by  J Bone

Photo by Nyree Fearnley

Photo by Nyree Fearnley

NF              12/11/20