Small Blue

  • Small Blue (upperwing)
    Small Blue (upperwing)
  • Small Blue (male & female)
    Small Blue (male & female)
  • Small Blue (underwing)
    Small Blue (underwing)
  • Small Blue (egg)
    Small Blue (egg)
  • Small Blue (caterpillar)
    Small Blue (caterpillar)
  • Video play iconSmall Blue (upperwing)
    Small Blue (video)
  • Small Blue (upperwing)
    Small Blue (upperwing)
  • Small Blue (male & female)
    Small Blue (male & female)
  • Small Blue (underwing)
    Small Blue (underwing)
  • Small Blue (egg)
    Small Blue (egg)
  • Small Blue (caterpillar)
    Small Blue (caterpillar)
  • Small Blue (upperwing)
    Small Blue (video)

Scientific name: Cupido minimus

Our smallest butterfly. Upperwings brown with blue dusting. Undersides pales blue with row of black spots.

Our smallest resident butterfly is easily overlooked, partly because of its size and dusky colouring, but partly because it is often confined to small patches of sheltered grassland where its sole foodplant, Kidney Vetch, is found.

Males set up territories in sheltered positions, perching on tall grass or scrub. Once mated, the females disperse to lay eggs but both sexes may be found from late afternoon onwards in communal roosts, facing head down in long grass. The butterfly tends to live in small colonies and is declining in most areas. Found throughout Britain and Ireland but rare and localised.

Size and Family

  • Family – Blues
  • Small Sized 
  • Wing Span Range (male to female) - 20-30mm

Conservation status

  • Listed as a Section 41 species of principal importance under the NERC Act in England
  • Listed as a Section 42 species of principal importance under the NERC Act in Wales
  • Classified as a Northern Ireland Priority Species by the NIEA
  • UK BAP status: Priority species
  • Butterfly Conservation priority: Medium                    
  • European Status: Not threatened                           
  • Protected in Great Britain for sale only

Caterpillar Foodplant

The sole foodplant is Kidney Vetch (Anthyllis vulneraria). The larvae live only in the flower heads where they feed on developing anthers and seed.

Distribution

  • Countries – England, Scotland, Ireland and Wales
  • Mainly South-central England and some eastern Scottish coasts and both east and west coast of Ireland
  • Distribution Trend Since 1970’s = Britain: -38%

Habitat

Rare but found on sheltered, warm grassland habitats which have Kidney Vetch. Habitats include; chalk and limestone grassland, coastal grasslands and dunes and man-made habitats such as; quarries, gravel pits, road embankments and disused railways.

Factsheets

Similar species