Distribution: W France, then French and Italian Alps northwards to
Belgium and Holland (where it has greatly reduce recently), Switzerland, Germany
and eastwards to Romania and S Poland.
Identification: Uppersides have large spots on a blue background with
very broad black margins. These are particularly broad in the female, often
leaving just a few scales in the basal areas. Please see the Maculinea ID page for more information on
separating the Large Blues.
Flight time: Flies from mid June to the end of August depending on
location and altitude.
Habitat: Usually damp meadows, sometimes at the edge of marshes and
lakes, with abundant larval food plant Sanguisorb officinalis.
Behaviour: Adults frequently visit the larval food plant for nectar.
Eggs are laid on the flower head. Young larvae are tended by ants and spend the
latter stages in the ant nest where they pupate.
Additional notes: Often flies with the Dusky Large Blue, M.
nausithous, which generally flies a week or two later.