Insects of Britain and Ireland: butterflies
Adults. Wingspan 34–42 mm (epiphron), or 46–52 mm (aethiops); the fringes conspicuously light-and-dark banded, or conspicuously light-and-dark banded to not banded. Slender-bodied to medium built; short-bodied. The eyes glabrous. Antennae reaching noticeably less than halfway to the wingtips, or reaching about halfway to the wingtips. The antennal clubs gradual-elongate; curved; flattened (blunt, pale beneath the tip). Labial palps ascending. Having only 4 fully developed legs. Fore-legs without a tibial epiphysis. Tibiae of middle legs 2-spurred. Posterior tibiae 2-spurred.
Forewings. Forewings apically blunt. The outer and hind margins angled at about 100–103 degrees (in E. aethiops), or 110 degrees (in E. epiphron). The outer margins convexly curved; not scalloped. Uppersides of the forewings dark brown, or fuscous; eye-spotted. The eye-spots 2–3, or 4–6; aligned posterior towards the apex to mid-posterior. Uppersides of the forewings without a discal mark; with an orange-red posterior band interrupted by the veins, containing black-ringed, white-centred ocelli, these 2–3 and conspicuous in E. aethiops, 4–6 and tiny in E. epiphron.
Hindwings. Hindwings broadly rounded; with the outer margins scalloped to with the outer margins not scalloped. Uppersides of the hindwings dark brown, or fuscous; conspicuously patterned. Uppersides of the hindwings eye-spotted (usually, sometimes obscurely), or not eye-spotted. The eye-spots 2–4; posterior towards the apex to mid-posterior, or posterior towards the apex to near the tornus. Uppersides of the hindwings without a discal mark; with a reddish-orange postmedian band containing white-centred ocelli or black dots.
Undersides of wings. Undersides of the forewings in E. epiphron colour-patterned like the uppersides or postmedianly paler and the ocelli even smaller or obsolete; in E. aethiops more or less resembling the upperside or paler postmedianly; eye-spotted, or not eye-spotted. The eye-spots 3–6 (sometimes obscure or obsolete in E. epiphron); posterior towards the apex to mid-posterior.
Undersides of the hindwings in E. epiphron colour-patterned like the uppersides or postmedianly paler and the ocelli even smaller or obsolete; in E. aethiops varying from light to dark, with a paler postmedian band that often includes three white dots; eye-spotted, or not eye-spotted. The eye-spots when present, 1–6; posterior towards the apex to mid-posterior. Undersides of the hindwings without a discal mark.
Wing venation. Forewings 12 veined; with basally dilated veins; vein 12 basally dilated; the lower margin of the discal cell not dilated; vein 1b not dilated. Forewings with 1 tubular anal vein; the anal veins of the forewings representing 1b only; vein 1b simple. Forewings with a discal cell; vein 2 departing from the hind margin of the cell in its distal quarter to departing from the cell less than three-quarters of the distance from its base (from about 2/3 the way out). Forewingveins 8 and 9 out of 7, 10 and 11 separate from the cell.
Hindwings 9 veined; without a praecostal spur; with 2 anal veins; exhibiting vein 1a; the anal veins comprising 1a and 1b. Hindwings with a closed discal cell; the transverse vein complete. 7 veins arising from the hindwing cell. The cell-derived hindwing veins all arising independently of one another.
Eggs, larvae, pupae. Eggs with an apical concavity, sub-globular (E. aethiops), or barrel-shaped (E. epiphron); longitudinally ribbed (with about 20 ribs). The larvae shortly hairy; without bristly spines. On grasses, with E. epiphron favouring Nardus stricta.
Pupae smooth and rounded; without shining-metallic markings; exposed, with no coccoon; not suspended, but attached at the tail and secured by a median girdle of silk (acording to the illustration of E. aethiops reproduced by South).
British representation. 3 species. Erebia aethiops (Scotch Argus), Erebia epiphron (Mountain Ringlet), Erebia ligea (Arran Brown, of uncertain taxonomic status). The adults abroad June to August.
Status in Britain. Indigenous.
Distribution. Northern Scotland, southern Scotland, northern England, and Ireland. Frequenting open places. Habitats calcareous and non-calcareous.
Classification. Superfamily Papilionoidea. Satyridae.
Illustrations. • Erebia aethiops (Scotch Argus): photos. • Erebia aethiops (Scotch Argus), E. epiphron (Mountain Ringlet) and E. ligea (Arran Brown): Kirby, 1907. • Erebia aethiops and E. epiphron: eggs, larvae, pupae. • Erebia ligea (Arran Brown): Stephens (1828). • Larva of E. ligea: Duponchel (1849). • Erebia epiphron (Mountain Ringlet): Stephens (1828). • Satyridae (1): Newman, 1871. • Maniola, Pyronia, Erebia, Aphantopus (Browns: Coleman, 1860).
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2008 onwards. Insects of Britain and Ireland: butterflies. Version: 16th May 2016. delta-intkey.com’.