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Small Blue butterfly

©Chris Lawrence

Small blue

The small blue's name is a little misleading: it is our smallest butterfly, but only shows a dusting of blue on brown wings. It is scarce, occurring on chalk grassland, mostly in southern England.

Enw gwyddonol

Cupido minimus

Pryd i'w gweld

May to August

Species information

Ystadegau

Wingspan: 1.8-2.7cm
Protected in the UK under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

Cynefinoedd

Ynghylch

The small blue is the smallest of all the UK's butterflies. Adults are on the wing from May to August and can be seen feeding on common bird's-foot-trefoil or horseshoe vetch on chalk grassland, but only where kidney vetch also grows - the sole foodplant of the caterpillars. Males set up territories in sheltered places and the females lay their eggs on the kidney vetch; the emerging caterpillars feed on the flowerheads.

Sut i'w hadnabod

Despite its name, the male small blue only has a small dusting of blue near to its body, otherwise it is a brown butterfly with pale, silver-grey underwings. The female is similar, but without the blue markings on the upperwings.

Dosbarthiad

Mostly found in southern England, but also in parts of Scotland and Wales.

Roeddech chi yn gwybod?

The small blue tends to live in small colonies of up to 30 individuals. Both sexes can be found in communal roosts, facing head down in the grass.