Scientific name: Thecla betulae
An elusive butterfly that spends most of its time either high in the canopy of trees or hiding in hedgerows.
It is worth looking up at prominent Ash trees along wood edges to see if small clusters of adults may be flitting around. They congregate to mate and feed on aphid honeydew. Adults also sometimes feed lower down on flowers such as Hemp-agrimony, Common Fleabane and Bramble. The females are most frequently seen as they disperse widely along hedgerows where they lay conspicuous white eggs on young Blackthorn shoots.
The butterfly often rests with its wings closed showing orange-brown underwings with two wavy white streaks and small tails. Uppersides are brown with an orange mark.
It is locally distributed in southern Britain and mid-west Ireland and has undergone a substantial decline due to hedgerow removal and annual flailing, which removes eggs.
Size and Family
- Family – Hairstreaks
- Small Medium Sized
- Wing Span Range (male to female) - 38-40mm
- Listed as a Section 41 species of principal importance under the NERC Act in England
- Listed as a Section 42 species of principal importance under the NERC Act in Wales
- UK BAP status: Priority Species
- Butterfly Conservation priority: High
- European Status: Not threatened
- Protected in Great Britain for sale only
The Butterfly breeds on the young growth of Blackthorn (Prunus spinosa) and occasionally other Prunus species such as Bullace (P. domestica).
- Countries – England, Wales, and Ireland
- Restricted in the UK to three main centres: south-west Wales, Devon/Somerset and Surrey/Sussex. Other smaller populations occur around Oxford and on Salisbury Plain.
- Distribution Trend Since 1970’s = -43%.
Hedges, scrub and woodland edge where Blackthorn is prominent and not flailed every year.
- Butterflies and farmland
- Hedgerows for Hairstreaks
- Woodlands for Butterflies and Moths
- Brown Hairstreak in Blackdown Hills Leaflet
- Brown Hairstreak in Wales
- Y Brithribin Brown_bh_Cym