Boloria polaris

Distinguished from the similar Boloria freija by more variable coloration and more variegated hindwing underside. The black median band on forewing above is heavier and more deeply sinuous proximally in B. polaris. The mother-of-pearl basal markings and silvery-toothed band on hindwing beneath are distinctive. Regular rows of submarginal spots in marginal area contrast with patterns in related species.

Wingspan 32–38 mm. Forewing above with heavy, deep black median band that is deeply sinuous proximally; marginal area with regular rows of submarginal spots. Hindwing beneath more variegated than related species, with mother-of-pearl markings in basal area and silvery teeth on narrow band separating central from marginal area. Forewing beneath almost as distinctly marked with black as above, but paler overall. Hindwing beneath with complex pattern of light and dark markings creating variegated appearance.

Mountain tundra near rocky areas; meadow tundra with host plant availability. Occurs in high-arctic and subarctic environments with low-growing vegetation.

Northernmost Scandinavia (Norway, Finland, Lapland), Greenland, northeastern Alaska, northern Canada (including Ellesmere Island), northeastern Russia, Chukotka. Subspecies B. p. erda in central and eastern Siberia; B. p. kurentzovi in Chukotka Autonomous Okrug and Wrangel Island; B. p. polaris in northern Scandinavia, Greenland and North America.

Adults fly late June to mid-July in mountain tundra populations; June to August depending on location across range. In Norway, Finland and Lapland, flight period is July and August.

Adults feed on nectar of Astragalus, Ledum (wild rosemary), and Dryas. Larvae feed on flowers and leaves of Dryas octopetala, Vaccinium myrtillus, Vaccinium uliginosum, and other Vaccinium species.

• Dryas octopetala - larval food plant
• Vaccinium myrtillus - larval food plant
• Vaccinium uliginosum - larval food plant
• Vaccinium sp. - larval food plant
• Astragalus - adult nectar source
• Ledum - adult nectar source
• Dryas - adult nectar source

Two-year development. Eggs laid singly or in groups up to 20 on caterpillar food plants; egg stage lasts just over two weeks. Caterpillars feed on flowers and leaves. Two hibernation periods under stones or moss: first after hatching (before which caterpillars do not feed), second at fourth instar. Pupation and adult emergence complete the cycle in second year.

In mountain tundra, adults stay near rocky areas. Females oviposit directly on larval host plants. Caterpillars seek shelter under stones or moss for hibernation.

Adults function as pollinators of tundra flowering plants. Larvae are herbivores that process plant biomass in high-arctic ecosystems. Serves as potential indicator species for high-arctic ecosystem health due to specific habitat requirements and sensitivity to environmental conditions.

Subject of entomological study due to extreme northern distribution and adaptation to high-arctic conditions. One of few butterfly species occurring at very high latitudes, making it of interest for studies of range limits and climate change impacts.

• Boloria freijaSimilar size and general pattern, but B. polaris has more variable coloration, more variegated hindwing beneath, heavier and more deeply sinuous black median band on forewing, and distinctive mother-of-pearl and silvery markings on hindwing underside

• arctic
• tundra
• fritillary
• butterfly
• high-latitude
• biennial life cycle

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
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