Marsh Fritillary larvae surveys

Ecofact have recently completed a number of larval surveys for the Marsh Fritillary Euphydras aurinia butterfly; the only Irish insect listed under Annex II of the EU Habitats Directive. The Marsh Fritillary has declined due to changing landuse, but is still widespread in Ireland.

Marsh Frtillary larval web, Co Sligo

The Marsh Fritillary butterfly Euphydryas aurinia is a species associated with wet grassland and heath habitat in Ireland. Although it is widely recorded in Ireland, it generally exists in extremely localised colonies. The eggs of the Marsh Fritillary are laid in batches on the underside of leaves and after emergence the larvae spin a large web on the ground and dozens of them will hibernate together until the spring. The butterfly is on the wing during late May and June and it is single brooded. The food plant of the caterpillar larvae of this species is known as Devil’s-bit Scabious Succisa pratensis.

According to NPWS, colonies can occur in a wide variety of habitats including calcareous grassland, fens, bogs sand dunes, and upland heaths and grasslands. Colonies need a sufficient area of habitat so that the species can survive. Populations vary greatly in size annually and this is partially related to cycles of parasitic wasps. Individual sites are thought to exist as part of a network of neighbouring sites that are used periodically as conditions permit. If the habitat patch is large enough, colonies may persist for many years.

Fen habitat with Devil’s-bit Scabious food plant

The optimimum time to survey for Marsh Fritillary is in the period September and October when the larvae can be found within silken webs on the leaves of its foodplant Devil’s-bit Scabious. Ecofact ecologists have extensive experience in both surveys for this species, and also management of the habitats it inhabits.

If you require any further information regarding Marsh Fritillary or any other macroinvertebrate, please do not hesitate to contact us at +353 61 419477 or

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