Marsh fritillary  (Euphydryas aurinia)

The marsh fritillary is listed on Appendix II of the Bern Convention, Appendix II of the EC Habitats and Species Directive and fully protected in Great Britain under the Wildlife and Countryside Act, 1981 (3).

The marsh fritillary (Euphydryas aurinia) has a highly patterned pale yellowish-brown upperside with orange-brown markings and brown spots (1), giving a stained glass appearance. The underside is light orange to brown with yellow spots. Females are generally larger than males (1). The caterpillars measure up to 2.7 centimetres in length and are black in colour with black spines along the back (2).

Distributed throughout Europe and into Asia. The species was once widespread throughout Britain but has suffered a huge decline and is now extinct in eastern Britain (3). A shocking 66 percent of the English populations known in 1990 had become extinct by 2000 (5).

Breeds in open grassy areas, such as damp tussocky grassland, calcareous grassland and heaths or mires. In all habitats an abundant supply of the main larval foodplant, devil's-bit scabious (Succisa pratensis) is essential (3).

The flight period occurs between mid-May to mid-July. A single brood is produced a year, and the eggs are laid in large batches on the underside of leaves (2). The larvae group together and form protective webs on the foodplant that are obvious towards the end of August. Larvae hibernate whilst they are still small, and emerge the following spring to complete their development (3). Individual caterpillars disperse to pupate near the end of April, and adults emerge about two weeks later (2).

Habitat loss and inappropriate management are the major factors responsible for the decline of this species. Massive losses of unimproved grassland have occurred as a result of the intensification of agriculture that started after the Second World War. The species requires extensive grazing by cattle or ponies (5), sheep grazing tends to be unsuitable because sheep eat devil's bit scabious, and graze the sward too short (7). A further problem arises because the marsh fritillary exists as 'metapopulations', a number of discrete populations connected by dispersal over large landscape areas. The species therefore requires a network of suitable patches of habitat in an area (3).

A number of agri-environment schemes provide grants to farmers that manage their land in a way that suits the marsh fritillary. The landscape-scale conservation required by this species causes problems, not least because it is currently unknown how large the network of patches needs to be to support a viable population (3). Butterfly Conservation currently operates a Marsh Fritillary Project, which has produced guidelines for landowners on how to manage their land for this species (6). The marsh fritillary is a priority species under the UK Biodiversity Action Plan, and a number of key sites have been forwarded as candidate SACs (Special Areas of Conservation) (4).

View information on this species at the UNEP World Conservation Monitoring Centre.

The UK Biodiversity Action Plan for this species is available at UK BAP.

For more information on the marsh fritillary see:

• Butterfly Conservation:
  www.butterfly-conservation.org/
• Butterfly Conservation's species action plan:
  www.butterfly-conservation.org/downloads.asp?PageId=73
• Asher, J., Warren, M., Fox, R., Harding, P., Jeffcoate, G., and Jeffcoate, S. (2001) The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford.