| Family | Nymphalidae |
|---|---|
| Subfamily | Heliconiinae |
| Genus | Boloria |
| Species | thore |
| Authority | (Hübner, [1804]) |
| English Name | Thor's Fritillary |
| European Red List 2010 | Least Concern (LC) |
|---|---|
| EU 27 Red List 2010 | Least Concern (LC) |
| European Red List 2025 | Least Concern (LC) |
| EU 27 Red List 2025 | Least Concern (LC) |
| Habitats Directive | |
| Bern Convention | |
| CITES |
In the Alps, Thor’s Fritillary can be found in flower-rich places, in clearings, or in sheltered “alcoves” at the edges of woods. It prefers damp, north-facing slopes, and is often found beside streams or in ravines. In the Scandinavian part of its range, the butterflies can be seen in clearings in birch woods and coniferous forests, and near mountain lakes, swampy places, in gullies, and river beds. The Yellow Wood Violet (Viola biflora) is its major foodplant, but other violets are used as well. The female lays her eggs either on the foodplant, or on a neighbouring plant, and the caterpillars take nearly two years to develop.
Austria / Belarus (Possibly Present) / Finland / Germany / Italy / Italy: Mainland / Liechtenstein / Lithuania (Regionally Extinct) / Norway / European Russia / Slovenia / Sweden / Switzerland /
No larval foodplants are available for this species.