Host plants:
The larvae feed on flowering shrubs and perennials. More important are Frangula alnus, Calluna, Lythrum and some Fabaceae.
Habitat:
Celastrina argiolus occurs in shrub-rich areas from woodland edges, riparian forests, clearings up to gardens (frequent egg-laying at Lythrum around a garden pond near Memmingen/Germany). Usually the adults are observed more singly but widespread because they are little sedentary. In the Alps, Celastrina argiolus is restricted to the valleys. In Northern Greece I met sometimes higher abundances of butterflies feeding on Sambucus ebulus and Mentha sp. (e.g. Olympus, 800m asl, July 2012)
Life cycle:
There are most often two generations from April to June and again from mid-July to early September. Celastrina argiolus overwinters as a pupa.
Endangerment factors:
Dark forest management and the uniformization of the landscape is harmful for Celastrina argiolus even if it is still widespread and has low requirements concerning habitat quality.
Remarks:
Celastrina argiolus shows an holarctic distribution pattern and occurs in most of Europe (misses only in the extreme north), in North Africa, parts of Asia and North America.