In Cumbria, the Brimstone is exclusively located in the south of the county mainly around the Morecambe Bay area, which is almost at the northernmost limit of its range in mainland UK. It is fairly common both in our woodlands and along hedgerows but will also come into rural gardens. It is not thought to be under threat although further south in the UK the spread of the Harlequin ladybird is a problem as its larvae devour the Brimstone larvae. Neither sex will open its wings whilst at rest but in the resting position the uniquely sculptured shape of its wings is displayed wonderfully. Males are a bright pale sulphur yellow, females are a very pale white/green: both have distinctive orange/brown spots in the centre of each wing.
Where to look
Can be found almost anywhere: try the bottom (roadside) ride in Brigsteer Woods, SD 486876 or anywhere on Arnside Knott, SD 455774.
When to look
One of the first butterflies to emerge, look on warm sunny days in early April, perhaps even late March, through to late Summer.