Butterflies of Finland

Butterflies of Finland: overview

Finland is a boreal country with a harsh climate and rich bog ecosystems. About 120 species of day-flying butterflies are recorded — modest by European standards, but the fauna is highly specialized: bog and taiga species rare or absent in most other countries.

The observation season is short — May through August — but intense: in a few summer weeks you can see the full diversity of local entomofauna.

Characteristic biotopes and species

Raised bogs

Finland is a country of bogs: more than 30% of the territory is peatland. This is a unique biotope for several species:

• Pearl-bordered fritillary (Boloria aquilonaris) — lives exclusively on raised bogs; host plant is cranberry
• Bog fritillary (Boloria eunomia) — wet meadows and bogs
• Marsh fritillary (Euphydryas aurinia) — on wet meadows with devil's-bit scabious

Taiga

Old-growth taiga forests support purple emperor (Apatura iris) and several forest blues. Pine forests are home to poplar admiral (Limenitis populi).

Southern Finland and the coast

The richest region by species. In summer, migrants from Central Europe arrive — painted lady, red admiral. In warm years, southern species that usually do not reach Finland appear.

Arctic species

In the north, in Lapland, true arctic species occur:

• Heath's sulphur (Colias hecla) — arctic, flies in July in mountain Lapland
• Jutta arctic (Oeneis jutta) — bog pine forests

Season and phenology

Because of the short summer, many Finnish species have only one generation per year (annual cycle or even two-year in some arctic species). Emergence is synchronized — late May through July. August already feels like autumn, though the last butterflies fly until September.