Marsh fritillary

Marsh fritillary

Marsh fritillary © Ross Hoddinott/2020VISION

marsh fritillary

Ross Hoddinott/2020VISION

Marsh fritillary caterpillar

Marsh fritillary caterpillar © Vaughn Matthews

Marsh fritillary

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Enw gwyddonol: Euphydryas aurinia
This beautiful butterfly is one of our rarest, now mostly restricted to the western parts of the UK.

Top facts

Stats

Wingspan: 30-50mm

Conservation status

Listed as a Section 41 species of principal importance under the NERC Act in England
UK BAP status: Priority Species
Butterfly Conservation priority: High
European Status: Vulnerable

Pryd i'w gweld

Flies May to July

Ynghylch

As the name suggests, the marsh fritillary is often found in wet and boggy places, like damp meadows, but can also be seen in a variety of other habitats where there's plenty of sun and scabious for the caterpillars to feed on. Devil's-bit scabious is the foodplant of choice, but they will occasionally eat field scabious or small scabious.

The adult butterflies usually begin to emerge in May and can be seen flying into summer. Males will set up small territories, perching on flowers or grass stems and rushing up to meet any passing butterflies in the hope of finding a female. Once a female has mated, she will search for a suitable foodplant and lay a large cluster of eggs on the underside of a leaf - the clusters can contain over 300 eggs!

The eggs hatch after a few weeks and the tiny caterpillars spin a silk web, binding the leaves of the foodplant together. They live communally in these webs, feeding on the leaves. In late summer, they make a new communal web in which to spend the winter. They'll emerge around March to continue feeding, before pupating in a colourful chrysalis that hangs from a plant.

The marsh fritillary is one of our most threatened butterflies, having suffered severe declines in recent decades both in the UK and more widely in Europe. Local populations can fluctuate greatly from year to year, depending on weather, food availability and the abundance of a parasitic wasp that uses the caterpillars as hosts for its own offspring.

What to look for

A brightly coloured butterfly, with a mosaic of orange, yellow, and brown markings on the upper surface of both the forewings and hindwings, which form distinct rows of the same colour. There is a prominent row of small black spots towards the outer edge of each hindwing.

Where to find

Now mostly restricted to the west of Scotland, Northern Ireland, south and west Wales, and the southwest of England, with a few scattered populations elsewhere.

Roeddech chi yn gwybod?

This beautiful butterfly has also been known as the greasy fritillary, due to the sheen that develops on the wings as they wear.