Brown Hairstreak

Thecla betulae


The largest of the UK hairstreak family, the brown hairstreak is an elusive butterfly, spending most of the time either high in the tops of ash "master" trees, where they feed on honeydew from aphids and bask in the sun, or amongst thick hedges.  Adults fly from late July, peaking in August, and can remain on the wing until November.  They are found on woodland edges and hedgerows in Southern England, laying their eggs on blackthorn. 

How to identify

The brown hairstreak is the largest hairstreak found in the UK. The top side of the wings are brown but females have an orange mark in the top corner of each. The underwings are a distinctive bright orange with two white lines streaked across and small tails protruding from the lower wing.

Where to find it

Found in England and Wales. A local species centred around distinct colonies.


When to find it

Adults are on the wing from late July

  • July
  • August
  • September

How can people help

The Wildlife Trusts manage many grassland and woodland edge habitats sympathetically for the benefit of all kinds of butterflies, including the brown hairstreak. Careful hedge-cutting at the right time of year and allowing blackthorn suckers to grow without being cut or grazed every year are just some of the ways that their habitat is kept in good condition - supporting many other invertebrates and, in turn, the larger animals that prey on them. By volunteering for your local Trust you can help too and you'll make new friends and learn new skills along the way.

Species information

Common name
Brown Hairstreak
Latin name
Thecla betulae
Butterflies and moths
Wingspan: 3.6-4.5cm
Conservation status
Biodiversity Action Plan (BAP) priority species as they have suffered a sharp decline due to inappropriate hedgerow management