Identifying features
Wingspan: 20-30 mm. The upperside of the male is sky blue with a sharp, black border, and sometimes with lines that can reach approximately.
Similar species
The species is often confused with Silver-studded blue, so it is important to be able to distinguish between them before entering one instead of the other. Idas blue resembles Silver-studded blue extremely closely.
Distribution
Widespread in Jutland, except for the southeast part, as well as on Læsø, Samsø, Bornholm, and the north coast of Zealand, Ulvshale on Møn, and Holmegårds Mose and Feddet. Currently, no other known locations are found in Denmark.
Biology
The larva lives in Denmark, primarily on common heather, common bird's-foot trefoil, and other plants from the pea family.