Geographical variation and subspecific status of Thor’s Fritillary Clossiana thore (Hubner, 1803) in northeastern European Russia

Quantitative analysis of geographic variation in Clossiana thore supports the recognition of two subspecies in northeastern European Russia. C. thore transuralensis (Shel.) occurs in the Bolshezemelskaya tundra and Ural Mountains (Northern, Subpolar, and Polar Urals). It is characterized by a smaller size (male forewing length 16.5–20.5 mm; female 17.5–21 mm), extensive wing nigrism (>50 % forewing and >75 % hindwing surface coverage), with submarginal black spots elongated along veins. Southern taiga populations belong to C. thore excellens (Krul.), exhibiting larger size (male forewing 18–23 mm; female 18.5–23.5 mm) and reduced nigrism (<75 % wing surface), with more contrasting pattern elements.