Small Blue Butterfly - Cupido minimus

Phylum: Arthropoda - Class: Insecta - Order: Lepidoptera - Family: Lycaenidae

Small Blue butterfly, wings closed

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 wings of females are dark grey - almost black in many instances, while the wings of males are quite similar with just a light dusting of bluish scales near the base of the wings.

Small Blue butterfly, wings closed

The pictures show a male Small Blue; they were kindly contributed by Simon Harding.


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 to 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.

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