61.010 Cupido minimus (Small Blue)
ws: 18-27mm; bivoltine in south May-Jun, Jul-Aug, univoltine in north Scotland Jun; kidney vetch (Anthyllis vulneraria); mainly a species of chalk and limestone downs in S.England and S.Wales but colonies also exist in Cumbria, Scottish Borders and N.Scotland.
ID: male upperside is blackish with a blue sheen, female is brown. The undersides are quite similar to Celastrina argeolus (Holly Blue) but this is easily distinguished by its bright blue upperside.
Page published 18/07/2014 (§1)