Marsh Fritillary
Euphydryas aurinia/merope

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The status of these species is uncertain, not least because of confusion of true taxa with local altitudinal forms. All but two of the pictures below are from the Swiss Alps and probably represent what recent authors recognise as Euphydryas merope (scroll down for map of the relative distributions).

Euphydryas merope

Mating pair, Swiss Alps, May 2017

Euphydryas merope

Male, Swiss Alps, May 2017

Euphydryas merope

Female, Swiss Alps, May 2017

Euphydryas merope

Female, Swiss Alps, July 2013

Euphydryas aurinia

Male (I think), photographed west of Geneva, so quite possibly Euphydryas aurinia, not E. merope)

Euphydryas aurinia debilis

Male, Swiss Alps, July 2013

Euphydryas merope

Male, Swiss Alps, July 2013

Euphydryas aurinia debilis

Female, Swiss Alps, July 2012

Euphydryas aurinia debilis

Aberrant individual, Swiss Alps, August 2013

Euphydryas aurinia debilis

Mating pair, Swiss Alps, July 2011

Male, Swiss Alps, May 2005

Male, Swiss Alps, May 2007

Male, Swiss Alps, May 2007

Female, Swiss Alps, June 2007

Variety lacking postdiscal spots on the hindwing, Swiss Alps, June 2007

France (So Euphydryas aurinia, not E. merope)

Euphydryas aurinia caterpillar

Caterpillar, Switzerland, July 2012

Euphydryas aurinia distribution

Distribution - note: in much of the area shown above this species is very scattered and local

This very variable butterfly, with many geographical and altitudinal forms, has long been something of a taxonomical headache, especially in mountainous regions. Many books refer to the high altitude forms in the Alps and elsewhere as f. debilis, while others treat the alpine forms as a distinct species or subspecies, glaciegenita. Leraut and Tshikolovets regard it as a distinct species, though differ as to its correct name (glaciegenita for Tshikolovets and merope for Leraut). I am not competent to judge the question! On my local mountain, marsh fritillaries appear from about May and fly through the summer in a single generation. At lower altitudes the butterflies are generally more colourful and are often larger. At the highest altitudes - on mountains at the eastern end of Valais, for example, they may be small and rather greyish. Nevertheless, I have seen great variation within the alpine populations.

Separation from other Euphydryas species is generally quite easy. In the Alps, the Asian fritillary lacks post-discal spots on the hindwing and is otherwise quite distinctive. Cynthia's fritillary flies in many of the same places as marsh fritillary. Males are obviously easy to separate - male Cynthia's fritillaries have the iconic white ground colour - but females may be more difficult. Female Cynthia's is larger, has a more open pattern and is generally more unicolourous orange (though I have seen some washed with pale). Other Euphydryas species are the rare scarce fritillary - which is very similar to Asian fritillary, and lacks the post-discal spots on the hindwing - and the Spanish fritillary. This last is larger and brighter, with a double black margin on the upperside, bordered internally by conspicuous, cream lunules.

This is a flower-loving butterfly. Males often defend their territories from flowerheads and frequently return to the same ones. The larvae feed on various species of scabious - including devil's bit scabious - and honeysuckles. They feed and hibernate gregariously in silken webs, dispersing in later instars before pupation.