The Glanville Fritillary butterfly

Glanville Fritillary butterfly
Glanville Fritillary butterfly Somerset, Uk photo Steve Ogden

The Glanville Fritillary is a rare butterfly in the Uk with its only significant population being on the south coast of the Isle of Wight.

In recent times a small population has appeared on the Hampshire coastline.

Another small population of unknown origin and sustainability has been periodically recorded at Sand Point in Somerset.

Populations are also found in the Channel Islands and throughout much of Europe.

Male Glanville Fritillary in Huesca, Spain – photo Paul Browning

The Glanville Fritillary is found extensively throughout much of Europe as far south as the southerly tip of Italy and Greece but absent from much of Spain and Portugal.

The male featured was photographed by Paul Browning in Huesca, Northern Spain.

Its distribution extends eastwards to Russia and as far north as southern Scandinavia.

Underside of Glanville Fritillary butterfly Somerset, Uk photo Steve Ogden

Identification of the Glanville Fritillary

This small to medium sized Fritillary has a wingspan of between 40-47mm with females slightly larger than males. The uppersides of both fore and hindwings are orange brown traced with black markings.

The underside of the hindwings have distinctive bands of orange and white with small black marks. The underside of the forewing is a light orange with less distinct black markings.

Females are larger and often paler than the males. Variations occur particularly in the amount of black.

More British fritillary butterflies are featured the British Butterflies gallery

Female Glanville Fritillary in Huesca, Spain – photo Paul Browning

In the British Isles there are only 8 species of resident Fritillary butterfly.

Similar sized ones are the Marsh Fritillary, The Heath Fritillary, Small-Pearl-bordered Fritillary and Pearl-bordered Fritillary.

In continental Europe there are more species, some with different forms/regional variations. The identification of some can be difficult.

Other European Fritillary butterflies are featured in the European Butterfly gallery

Glanville Fritillary caterpillar

Fully grown Glanville Fritillary butterfly caterpillar Alderney, The Channel Isles photo Ruth Gaudion.

The fully grown Glanville Fritillary caterpillar is c 26mm in length, black with white freckling, heavily coated with black, branched spines and with distinctive deep red head and legs.

Other butterfly caterpillars are featured in the Butterfly Caterpillar gallery.

Moth caterpillars are featured in the Moth Caterpillar Galleries and species pages.

Head of Glanville Fritillary butterfly caterpillar Isle of White photo Nigel Downes

Lifecycle of the Glanville Fritillary Butterfly

The Glanville Fritillary flies in a single generation between May and the beginning of July.

Glanville Fritillary caterpillar larval foodplants

The eggs are laid in large batches of up to 200 eggs on the underside of leaves of the larval foodplant, sea plantain (Plantago maritima) or ribwort plantain (P.lanceolata)

Other butterfly larval foodplants are featured in the Butterfly Larval Foodplant gallery

Glanville Fritillary caterpillars, south west France, photo Paul White

Emerging caterpillars are yellowish-white with black heads. After the third moult the head is brown and the body black.

The caterpillars live gregariously in a silken web and hibernate in August when in their 4th instar. After overwintering the caterpillars become active again in early Spring.

By March/April the caterpillars are fully grown, 25 mm in length, black with a red head, reddy/brown prolegs, black spines and white speckling.

Glanville Fritillary butterfly caterpillars Isle of White photo Jane Moore

Pupation takes place in thick vegetation with the chryslis attached to a plant stem.

Butterflies emerge within about 3 weeks.

Recommended reference books

A Cornwall Butterfly Atlas- John Watcher, John Worth & Adrian Spalding. A complete guide to British Butterflies-Margaret Brooks and Charles Knight. Collins Butterfly Guide -Tom Tolman & Richard Lewington.