Host plants:
The larvae feed on Polygonum bistorta, in Scandinavia also on Polygonum viviparum
Habitat:
Lycaena helle inhabits wetlands such as fens and bogs with the occurrence of larval host plant. The sites can be quite open, but also loosely wooded.
Life cycle:
The pupa hibernates. The small butterflies fly between late May and early July lively around the habitat and pursue other butterflies. The females are usually much more inconspicuous. Flower visiting occurs very often on the larval host plant, but also on other plants. Oviposition takes place on the lower leaf surface. The caterpillar lives until August.
Endangerment: threatened with extinction
Endangerment factors:
Lycaena helle is threatened with extinction due to habitat destruction (intensification, afforestation, eutrophication, drinking water extraction, drainage, overbuilding).
Remarks:
Lycaena helle occurs especially from Northern Europe (Scandinavia) and Poland to the east across northern Asia (to Amur region). Further south, it is very local in Central Europe and the Pyrenees.