The Small Blue is Britain's smallest resident butterfly, with a wingspan range of 1.8 to 2.7cm.
Despite the term 'blue' being part of its common name, there is in fact very little blue colouring in this butterfly. The upper wings of females are dark grey - almost black in many instances - while the upper wings of males are quite similar with just a light dusting of bluish scales, usually concentrated near the base of the wings.
Although isolated colonies of this pretty butterfly occur throughout Britain, the Small Blue is uncommon except on the chalk downs of south of England and along the calcium-rich southern coastal strip of Wales. If you visit South Wales a great place to see lots of Small Blue butterflies is Kenfig National Nature Reserve, where Kidney Vetch, its larval foodplant, grows in great profusion.
The Small Blue butterfly is also widespread and common throughout limestone-rich areas of Europe and Asia.
In Britain the only larval foodplant known to be used by the Small Blue is Kidney Vetch, Anthyllis vulneraria. The caterpillars overwinter, pupating in April and May.
The main brood of adults emerges in May and June, and there is a partial second generation in late July and early August in the south of England and South Wales.
This page includes pictures kindly contributed by, Simon Harding, and by Betty and Tony Rackham.
Please Help Us: If you have found this information interesting and useful, please consider helping to keep First Nature online by making a small donation towards the web hosting and internet costs.
Any donations over and above the essential running costs will help support the conservation work of Plantlife, the Rivers Trust and charitable botanic gardens - as do author royalties and publisher proceeds from books by Pat and Sue.