Scotch Argus

• Latin name: Erebia aethiops
• Family group: Browns
• Countries: England, Scotland
• Size: Medium

Resident

Range stable.

As its name suggests, this butterfly is found predominantly in Scotland where it flies in tall, damp grassland. In sunshine, males fly almost without rest, weaving low through the grass in search of a mate. In poorer weather they perch on grass clumps, flying out to investigate any passing brown butterflies. The females are far less conspicuous and spend most of their time basking.

The Scotch Argus is common and widespread in Scotland but has declined in the southern part of its range, especially in England where it is reduced to just two isolated sites.

Conservation status

• UK BAP status: not listed
• Butterfly Conservation priority: low
• European threat status: near threatened

European/world range

Mountain areas throughout Europe from central France east to the Urals and western Siberia, but not in Scandinavia. It has declined recently in several European countries.

Foodplants

The main foodplant in Scotland is thought to be Purple Moor-grass (Molinia caerulea) and the populations in northern England use Blue Moor-grass (Sesleria caerulea). Though there are few observations from Britain, other grasses may be used, as they are in continental Europe.

Habitat

The Scotch Argus occurs in damp, acid or neutral grassland up to 500 m in montane regions of Scotland, and around the fringes of sheltered bogs, in woodland clearings, and young plantations. In northern England it is now restricted to two sites that contain a mosaic of sheltered limestone grassland, scrub, and woodland. The butterfly is found only in tall grasslands that are lightly grazed or ungrazed.