Our only green butterfly. The green is actually only on the underwings: the upperside is pale brown, but rarely seen. A small butterfly.
Where to see
- Habitat: Found in a variety of habitats: calcareous grassland, woodland rides, moorland and rough scrubby grassland.
- Caterpillar foodplants: The caterpillar foodplant depends on the habitat. In calcareous areas it will be the Common Rock-rose or Common Bird's-foot trefoil. On heathland, they use Gorse, Broom and Dyer's Greenweed. Other foodplants can include Bilberry, Dogwood, Buckthorn, Cross-leaved Heath and Bramble.
- Best places: Widely distributed, but generally in small colonies, so it can be difficult to find. Try Upton Country Park, Bindon Hill (near Lulworth), Cashmoor Down or the Cerne Giant hillside.
Distribution map
Green Hairstreak was recorded from these 1km squares in Dorset (2020-24).
- Key:
- 1 record
- 2-9 records
- 10+ records
When to see
Mainly May and into June, sometimes a little earlier or later.
Sightings by month (last 5 years)*
This year and last*
What to look for
The male and female look very similar. You may be able to differentiate them by their behaviour: the males may be seen having territorial battles with each other, after which the winner retires to his favourite perch on a prominent bush from 1-2 meters up, where he is easy to watch or photograph. The female is more often seen fluttering around bushes or plants where she searches to find good places to lay her eggs.
Both have brown uppersides and will therefore look brown in flight. When resting, their wings are always closed, so you only see the green undersides. These have a white dotted line on the hindwing, but this is very variable, to the point where it may be one white spot or nothing at all, while it can sometimes extend onto the forewing (see the photo at the top of the page). Some will have a brownish edge to the forewing where it disappears behind the forewing. All the Hairstreaks have small tails to the hind wings.
Some specimens (fresher ones?) will have a brown edge to the wing, and a small white fringe.
Photo gallery
Click thumbnails to view full-size images.
Green Hairstreak, showing some brown to the back of the forewing and demonstrating the smallness of the butterfly compared to the bluebell. Photo: Penny Hawes
Green Hairstreak showing the brown border and white fringe. Photo: Mark Pike
Green Hairstreak with more brown than usual on the underwings. Photo: Derek Fowler
Green Hairstreak with a notch out of its wing, probably from a bird attack, showing the brown of the upper wings in comparison to the more faded brown of the undersides. Photo: Ken Dolbear
Green Hairstreak with white marks extending across hind wing. Photo: Ken Dolbear
Green Hairstreak showing only one white spot on the hindwing. Photo: Brian Arnold.