In early June, Marsh Fritillaries glide over Cornwall’s damp meadows. Their life depends on Devil’s-bit Scabious, choosing its lush leaves for eggs. Lightly grazed, flower-rich grasslands keep this delicate cycle alive, ensuring the butterfly returns each summer.
In the quiet shimmer of a Cornish damp meadow in June, you might catch a flash of patterned orange drifting over the lush grasses. It settles, wings opening to reveal a mosaic of orange, brown, and cream. The Marsh Fritillary (Euphydryas aurinia) is one of Britain’s most beautiful and vulnerable butterflies, and here in Cornwall, its fate is bound entirely to a single plant — the Devil’s-bit Scabious (Succisa pratensis).
The Marsh Fritillary is a smaller, rounder-winged fritillary with a wingspan of 31–46mm. Its upper wings are a patchwork quilt of warm orange, rich brown, and pale cream, each cell outlined with precision. The underside mirrors this complexity in softer tones, marked with cream spots and paler lines. No two individuals are patterned quite the same, yet all carry the unmistakable checkered beauty that sets them apart.
In Cornwall, the Marsh Fritillary thrives only where meadows remain damp, species-rich, and unimproved. These are not the clipped, fertilised fields of modern agriculture, but living tapestries of purple moor-grass tussocks, sedges, and wildflowers.
You will find them in places like Breney Common, Goss Moor, Bodmin Moor’s edges, the damp sweeps of The Lizard, and tucked into low-lying marshy grasslands near the coast. Light cattle grazing shapes these swards, keeping them open yet diverse, allowing Devil’s-bit Scabious to flourish among the grasses. Sheep grazing, by contrast, can strip away both the flowers and the sheltering webs of the butterfly’s larvae.
These meadows are rarely uniform. They are mosaics — short grassy patches warmed by the sun, taller tussocks for shelter, and wetter hollows where scabious stems rise above the sward. The soil is low in fertility, the water table often high, and the rhythm of the land still guided by traditional management. While Molinia caerulea (purple moor-grass) tussocks are typical, the best sites hold them in balance with diverse wildflowers, as unchecked dominance by Molinia can reduce suitability for the butterfly.
Every stage of the Marsh Fritillary’s life turns around the fortunes of Devil’s-bit Scabious. In Cornwall, this plant forms basal rosettes in spring, then sends up slender stems topped with purple pincushion blooms from July into autumn. In lush meadows, flowering can begin as early as June, but for the butterfly, the abundance of mature leaves in late spring is the true cue for egg-laying.
Early Summer:
From late May into June, adults emerge—this is their most visible moment, drifting between flowers in the long light of early summer. They feed, court, and mate in warm, sunny spells, favouring meadows where scabious leaves are broad and abundant.
Egg-Laying:
By mid-June, females seek the underside of mature scabious leaves, laying clusters of 20 to over 100 eggs. The plants chosen are often the most robust in the meadow, ensuring enough food for the larvae to come.
Larval Growth:
Eggs hatch in July. The caterpillars feed gregariously, spinning dense silken webs over the leaves and stems of their host plant. As summer fades into autumn, the caterpillars hunker down in smaller webs at the plant’s base, entering a communal hibernation.
Overwintering and Reawakening:
Through Cornwall’s mild, damp winters, the caterpillars remain hidden in tussocks, often enduring short-term flooding without harm. By February or March, they wake to feed again on fresh scabious leaves, growing quickly before pupating in late April or May. Cutting or mowing is avoided in key larval areas during the growing season, with any management typically done late season and in rotation to protect caterpillars and their webs.
The cycle completes when adults emerge again in early summer, just as the next flush of scabious leaf and growth begins.
Many of Cornwall’s best Marsh Fritillary sites are near the coast, where damp grasslands meet salty air. These places support strong stands of scabious and offer varied microclimates. More importantly, they form part of a network — a series of meadows within a kilometre or two of each other. This “metapopulation” structure is vital because Marsh Fritillary colonies naturally rise and fall. When one site declines, nearby meadows can send in new colonists. Without this connectivity, local extinctions become permanent losses. Coastal grassland clusters help buffer the species against such decline.
The Marsh Fritillary’s vulnerabilities are many. Drainage, ploughing, reseeding, and fertilising wipe out wildflower-rich meadows. Too much grazing — especially by sheep — reduces Devil’s-bit Scabious biomass and destroys larval webs. Too little grazing allows scrub to smother open ground.
Conservation practice in Cornwall focuses on a few core principles:
Landowners working with agri-environment schemes often receive advice and funding to sustain these conditions, ensuring that the meadows continue to host both the butterfly and its supporting wildflower communities.
If you step into a Cornish meadow in early June, you may see a Marsh Fritillary settled on a scabious bud, wings outstretched to the sun. The purple of the flower sets off the orange and cream of the butterfly in a brief, perfect harmony. It is a moment shaped by months of hidden life in the grass, by centuries of traditional meadow care, and by the quiet resilience of a plant and insect that have shared the same damp corners of Cornwall for generations.
Protect the meadows, and you protect the story—the Marsh Fritillary will keep flying as long as Devil’s-bit Scabious blooms and grows in the summer light.
The Marsh Fritillary is one of Cornwall’s most striking early summer butterflies — but also one of its most elusive. Knowing when, where, and how to look will greatly increase your chances of finding this rare species.
The Marsh Fritillary is closely tied to damp, species-rich meadows and moor edges where Devil’s-bit Scabious grows in abundance.
Top sites in Cornwall include:
Look for areas where purple moor-grass tussocks, sedges, and wildflowers create a mosaic, with plenty of sunny open patches.
The Marsh Fritillary is a protected species and easily disturbed.
By visiting these sites respectfully, you are also supporting the conservation of Cornwall’s rarest meadow habitats. Lightly grazed, unfertilised damp grasslands are essential for this butterfly’s survival — and they are also home to a wealth of other wildflowers and pollinators.
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