The pearl-bordered fritillary (''Boloria euphrosyne'') is a

butterfly Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

of the family

Nymphalidae The Nymphalidae are the largest family of butterflies, with more than 6,000 species distributed throughout most of the world. Belonging to the superfamily Papilionoidea, they are usually medium-sized to large butterflies. Most species ha ...

found in Europe and through Russia across the

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

to the north of Kazakhstan.

Description

The adult butterfly is orange with black spots on the upperside of its wing and has a wingspan of 38–46 mm. The underside of the wings have a row of silver-pearly markings along the edge, which give the species its name. The pearl-bordered fritillary is often confused with the small pearl-bordered fritillary, but can be distinguished by the triangle along its pearl border (the small pearl-bordered has black chevrons) as well as the presence of a single silver spot in the middle of a row of yellow spots. The female has darker markings and rounder wings than the male. The

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

s are black with white or yellow spines along their backs. Like other species of fritillary, the males have special scent glands on their wings so that they can be recognised by females of their own species and therefore find a suitable partner.

Description in Seitz

''A. euphrosyne'' L. (= ''niobe'' Mull.) (67h). Very similar to the preceding species , especially ''selene'', but brighter red and the black markings thinner in typical specimens. Easily recognized by the hindwing beneath, which is bright brick-red at the base, not brown as in selene, the median band bearing only one silver-spot (across the apex of the cell) and the incomplete silvery band in the distal area being replaced by some yellow smears without any silvery gloss. The silvery marginal spots of the hindwing beneath are but very rarely absent. Grand collier argenté MHNT CUT 2013 3 21 Lalbenque Dos.jpg, Dorsal side Grand collier argenté MHNT CUT 2013 3 21 Lalbenque Ventre.jpg, Ventral side File:Boloria euphrosyne (5696960703).jpg, Close-up of wing scales

Distribution

The pearl-bordered fritillary is widespread throughout Europe, ranging from

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

to northern

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

and from

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

eastwards across the

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

and to the north of Kazakhstan. In England and Wales (plus another 10 countries) it has declined rapidly in number and is a highly threatened species.

Subspecies

*''B. e. euphrosyne'' – Central Europe, Siberia *''B. e. fingal'' ( Herbst, 1804) – Northern Europe, Siberia *''B. e. rusalka'' ( Fruhstorfer, 1909) – Southern Europe, West Siberia *''B. e. orphana'' (Fruhstorfer, 1907) – Transbaikalia, Amur, Ussuri *''B. e. kamtschadalus'' ( Seitz,

909 __NOTOC__ Year 909 ( CMIX) was a common year starting on Sunday of the Julian calendar. Events By place Britain * King Edward the Elder and his sister, Princess Æthelflæd of Mercia, raid Danish East Anglia and bring back the relics o ...

– Kamchatka, North Sakhalin *''B. e. umbra'' (Seitz,

– Altai, Sayan *''B. e. dagestanica'' (Sovinsky, 1905) – Caucasus, Transcaucasia *''B. e. nephele'' ( Herrich-Schäffer,

847 __NOTOC__ Year 847 ( DCCCXLVII) was a common year starting on Saturday of the Julian calendar. Events By place Europe * Danish Vikings land in the Breton March (western part of Gaul). Duke Nominoe of Brittany fails to withstand them ...

– Urals, Siberia

Lifecycle

Food plants and eggs

After mating, the female will lay her eggs on dead

bracken Bracken (''Pteridium'') is a genus of large, coarse ferns in the family (biology), family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that undergo alternation of generations, having both large plants that produce spores and small ...

(''Pteridium aquilinum''), or leaf litter near to

violet Violet may refer to: Common meanings * Violet (color), a spectral color with wavelengths shorter than blue * One of a list of plants known as violet, particularly: ** ''Viola'' (plant), a genus of flowering plants Places United States * Vi ...

plants – common dog–violet (''

Viola riviniana ''Viola riviniana'', the common dog-violet, is a species of flowering plant in the family Violaceae, native to Eurasia and Africa. It is also called wood violet and dog violet. It inhabits woodland edges, grassland and shady hedge banks. It is ...

''), heath dog–violet ('' Viola canina'') or marsh violet ('' Viola palustris''). Sometimes eggs are laid on the leaves of the food plant itself. They are laid singly, not in one large group such as the

marsh fritillary The marsh fritillary (''Euphydryas aurinia'') is a butterfly of the family Nymphalidae. Commonly distributed in the Palearctic region, the marsh fritillary's common name derives from one of its several habitats, marshland. The prolonged larval st ...

. The habitat mosaics they prefer are typically one–third grass and two–thirds bracken. Eggs can be found on the food plant from mid–May to the end of June. They are a pale yellow and can hatch after 10–14 days.

Caterpillar, pupa, and adult

The emerging caterpillars begin feeding immediately and will moult three times within the first 5–6 weeks. Each caterpillar will then

hibernate Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most ...

in a shriveled leaf at the base of the plant, usually moving to the hibernation site at the end of July. The caterpillars lose half of their body mass by the time the emerge in the following March. After a period of feeding and growth, during which it moults one last time, the caterpillar is full size and ready to pupate. The

chrysalis A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages the ...

stage is formed among the leaf litter, and lasts just 10–14 days. The adult butterfly flies between late April and June, and is one of the earliest fritillaries to emerge. Adults feed on the nectar from early spring flowers such as

bugle The bugle is a simple signaling brass instrument with a wide conical bore. It normally has no valves or other pitch-altering devices, and is thus limited to its natural harmonic notes, and pitch is controlled entirely by varying the air a ...

dandelion ''Taraxacum'' () is a genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus has a near-cosmopolitan distribu ...

, and

lesser celandine ''Ficaria verna'' (formerly ''Ranunculus ficaria'' ), commonly known as lesser celandine or pilewort, is a low-growing, hairless perennial flowering plant in the buttercup family Ranunculaceae. It has fleshy dark green, heart-shaped leaves and d ...

. There is a second brood during August.

Habitat

* Woodland clearings, recently coppiced or clear-felled, with

, or leaf litter provided by

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

and

bramble ''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, most commonly known as brambles. Fruits of various species are known as raspberries, blackberries, dewberries, and bristleberries. I ...

* Well-drained habitats with mosaics of grass, bracken, and light scrub * Hot and freshly cut material * Abundant food plants growing in short, sparse vegetation, where there is abundant dead plant material, bracken is preferred * Scrub edges can provide good breeding conditions, e.g.

gorse ''Ulex'' (commonly known as gorse, furze, or whin) is a genus of flowering plants in the family Fabaceae. The genus comprises about 20 species of thorny evergreen shrubs in the subfamily Faboideae of the pea family Fabaceae. The species are na ...

Management

* A network of paths running through bracken to open the canopy, allows sunlight through to help germinate any violet food plants. This can be achieved through grazing especially during winter and early spring.

Cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

are better than

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

as their extra weight helps to trample and break up any dense standing dead stems. Also there is a risk that sheep tend to eat plants, (for example '' Ajuga reptans''/bugle), that provide nectar for the adult pearl-bordered fritillary. Another way of achieving this is by cutting and bruising the bracken, a proportion of the site at a time, during May and early June. * Burning can be useful for reducing the litter of

, although follow up management is required as extra bracken growth will be stimulated as a result. This will kill a proportion of invertebrates, and therefore only burning a proportion of the site, e.g., 20% is suggested. * Spraying can be useful for reducing high densities of bracken litter, but care should be taken to not severely reduce the density and allow the grass to develop, as this will harm the breeding habitat. * Woodlands create sunny clearings and rides, but avoid using clearings that are dominated by other plants such as dog's mercury ('' Mercurialis perennis''),

common bluebell ''Hyacinthoides non-scripta'' (formerly ''Endymion non-scriptus'' or ''Scilla non-scripta'') is a bulbous perennial plant found in Atlantic areas from the north-western part of the Iberian Peninsula to the British Isles, and also frequently use ...

, and vigorous grasses.

Ecology

The Pearl-bordered fritillary (Boloria Euphrosyne) is a key indicator species for well-maintained open woodlands. It is one of the first butterflies to appear in spring, making it an early sign of a healthy habitat. The butterfly’s caterpillars rely on common dog violet (Viola riviniana) and other violet species for food, thriving in recently cleared or sunlit areas. These specific habitat needs make the species particularly sensitive to environmental changes. Adult fritillaries are strong fliers, preferring warm, sheltered grasslands, woodland clearings, and meadows with plenty of nectar sources. Their dependence on carefully managed landscapes highlights the importance of conservation efforts to maintain their populations.

Example sites where found

* Stansted Park, West Sussex, UK * Haldon Forest, Devon, UK * Lambert's Castle Hill, Dorset, UK * Hard Hills, Cornwall, UK grid ref SS 235176 *

References

Fox, R., Warren, M.S., & Thomas, J.A. (2001). The status of *Boloria euphrosyne* in the UK and its reliance on coppiced woodland. *Journal of Insect Conservation*, 5(3), 117-123. https://doi.org/10.1023/A:1011372000336

External links

Butterfly Conservation Organisation descriptionUK Butterflies organisation descriptionUK BAP website

'Grounded' Devon Wildlife Trust Newsletter

by

Butterfly Conservation Butterfly Conservation (BC) is a UK-wide nonprofit environmentalist organization and charity dedicated to conserving butterflies, moths, and the environment. The charity uses its research to provide advice on how to conserve and restore butterf ...

{{Taxonbar, from=Q127466 Boloria Butterflies of Asia Butterflies of Europe Butterflies described in 1758 Taxa named by Carl Linnaeus