Small Blue Butterfly - Cupido minimus

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

Small Blue butterfly, male, wings closed

Above: closed-woing view of a male Small Blue

The Small Blue is Britain's smallest resident butterfly, with a wingspan range of 1.8 to 2.7cm.

Female Small Blue butterfly laying eggs

Above: a female Small Blue laying eggs

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.

Small Blue butterfly, wings closed
Above: open-wing view of a male Small Blue butterfly

female Small Blue butterfly, open-wing view

Above: open-wing view of a female Small Blue butterfly


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.

Closed-wing view of a Small Blue butterfly

Above: Small Blue butterfly, a closed-wing view


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.

A mating pair of Small Bue buttewrflies

Above: mating Small Blue butterflies

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.

Studying butterflies and moths...

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