Thor's Fritillary
Common NameThor's Fritillary
Scientific NameBoloria thore
FamilyNymphalidae
SubfamilyHeliconiinae
Wingspan (mm)37.5
Wing Patternspotted
Primary Colorsorange, black, brown
HabitatSubalpine and alpine meadows, forest clearings, open woodlands, often near streams
Geographic RangeNorthern Europe, Russia, Siberia, Central Asia, North America (Alaska, Yukon, Northwest Territories, British Columbia, Alberta)
Host PlantsViola biflora, Viola palustris, other Viola species
Flight PeriodJune to August
Flight Stylefluttering
Conservation Statusleast-concern
Lifecycle NotesEggs are laid singly on host plants. Larvae feed on violets and typically overwinter as small caterpillars before pupating in the spring.
Identification TipsKey features include the specific arrangement of black spots on the orange upperside and the lack of silver spots on the hindwing underside, which helps distinguish it from other fritillary species.
Description
This butterfly displays an orange upperside adorned with a distinct pattern of black spots and a dark marginal band. The underside of the hindwing features a complex mosaic of orange, brown, and yellowish patches with intricate dark markings.
