Ribeog uaine in Gaeilge. The Green Hairstreak, Callophrys rubi, is Ireland’s only green butterfly and is easiest to find on upland heath and Gorse-scrub edges in May.
Identify it in four steps
- Underside vivid leaf-green (the only green butterfly in Ireland); this is the only surface ever visible in the field because it never opens its wings at rest.
- Upperside plain brown (rarely seen); a thin white line runs along the trailing edge of the hindwing underside.
- Wingspan 27 to 34 mm; a small, fast, spiralling flight low over Gorse, Bilberry, or scrubby heath.
- Perches head-down on Gorse or bramble with wings tightly closed; the green blends into new growth and makes it easy to overlook.
Habitat in Ireland
The Green Hairstreak occupies upland heath, bog margin, scrubby cliff, and Gorse-rich hedgerow. It uses a wider range of larval foodplants than most Irish butterflies, which is why it persists in habitat types where other species have gone.
Larvae feed on Bilberry (Vaccinium myrtillus) on upland heath, Gorse (Ulex europaeus) on lowland scrub, and Bird’s-foot Trefoil (Lotus corniculatus) on grassland edges. Adults nectar at Bilberry flowers, Hawthorn, and Gorse.
Where to see it
- the Wicklow uplands, Djouce and Sally Gap: Bilberry-rich upland heath produces reliable May records.
- Slieve Bloom Mountains, County Laois: heather-and-Bilberry mosaic on the plateau.
- Achill Island, County Mayo: coastal heath and Gorse-scrub edges with the species present into June.
Recorded across the upland-heath and coastal-heath fringe of Ireland in the National Biodiversity Data Centre atlas 2014-2019 and listed Least Concern in the Butterfly Conservation Ireland Red List (2010, revised 2019), though under-recorded because of its short flight period.
Related species
Recorded in 22 of 26 Irish counties in the National Biodiversity Data Centre atlas, with the strongest concentrations in Munster and eastern Leinster. Numbers dropped through the 2010s and partially recovered from 2019 onward.1
Source: National Biodiversity Data Centre butterfly atlas 2014 to 2019, and Butterfly Conservation Ireland annual review 2024.
