Dark Green Fritillary
Speyeria aglaja
Tap image to enlarge · Wikimedia Commons
Overview
The Dark Green Fritillary is the powerhouse butterfly of the Sefton Coast dunes. Large, fast-flying and striking, it careers across open dune grassland at speed, stopping to feed on Ragwort and thistles in sunshine. The Sefton Coast is one of the best places in northwest England to see it — the combination of open dune grassland and its larval foodplant (violets) makes it ideal. On warm days in July the numbers can be impressive. The green and silver underside gives it its name.
At a Glance
| Order | Lepidoptera |
| Family | Nymphalidae |
| Habitat | Open dune grassland · Coastal heath · Calcareous grassland |
| Diet | Adults: Ragwort, thistle, Viper's Bugloss nectar. Larvae: violets (Viola spp.) |
| UK population | Widespread but declining in England; strongholds in coastal dunes and upland grassland |
| Sefton Coast | One of the better northwest England sites; regularly seen in July on open dune grassland |
| Conservation | UK Green List |
Where to See It
Dune grassland at Ainsdale NNR and Formby. Forages on Ragwort and thistles.
Identification
Large orange-brown butterfly with black spots above. Underside hindwing has green wash with large silver spots — distinctive. Fast, powerful flight.
Viewing & Photography Tips
Visit Ainsdale NNR on a hot, sunny day in July. Watch Ragwort and thistle patches for feeding adults. They are fast but will feed for several minutes if undisturbed.
Conservation Status
UK Green List
This species has a favourable conservation status in the UK and remains an important part of Sefton Coast biodiversity.
Frequently Asked Questions
Where is the best place to see Dark Green Fritillary on the Sefton Coast?
Ainsdale NNR is the most reliable site — walk the open dune grassland on a hot, sunny day in July (temperatures above 20°C are ideal). Look for large, fast-flying orange butterflies visiting Ragwort and thistle flowers. The boardwalk trail passes through good habitat.
Why is the Dark Green Fritillary called 'dark green'?
The name refers to the underside of the hindwing, which has a distinctive green wash with large silver spots — not the upper surface, which is orange-brown. The underside is only visible when the butterfly settles with wings closed, which it does occasionally when roosting in vegetation.
Related Species
Plan your visit to the Sefton Coast
Marshside RSPB, Formby pinewoods, Ainsdale NNR — practical guides to getting there, what to bring, and the best spots for each season.