Colias tyche (De Boeber, 1812)

Host plants:
According to literature the larvae feed on Vaccinium (especially V. uliginosum), but reputedly also on Astragalus alpinus. The latter is also often used by the adults for nectar.

Habitat:
Colias tyche usually inhabits mountain tundra and open places with tundra vegetation between open birch woodland or scrubby willows up to 1000m. These sites are often partly wet or include smaller bogs, but also drier parts.

Life cycle:
The butterflies occur early in the season from late May to early or mid-July. The larva hibernates half-grown and pupates in the following year. The pupa hibernates again.

Remarks:
Colias tyche occurs locally around the Arctic, so in N-Scandinavia, polar N-America and very locally and sporadically in N-Asia (e.g. NE-Sibiria).