Marbled White

Marbled White Melanargia galathea (Linnaeus 1758)

Family: Nymphalidae, subgroup Satyrinae (The Browns)

Description

Left hand hand photo above by J Bone

Middle photo above by Paul Stephensen

Right hand hand photo above, plus header photo by Sarah Bradshaw

The Marbled White is a medium to large butterfly with a unique appearance. It looks exactly like its name suggests; marbled black and white. It cannot usually be confused with any other species. The males and females look alike except that females are larger with a yellow-ish tinge on the underside of their wings.

In wet periods or at night these butterflies can easily be spotted at rest with folded wings on grass stems or flower heads. Marbled Whites often feed communally, with a preference for purple nectar plants.

The flight pattern is slow and relaxed looking.

Habitat

The species is found on grazed chalk and limestone grasslands with a mix of fine and coarse grasses up to about half a metre tall. It prefers sites which are sheltered and south facing. It also can be found on non-calcareous grassland, woodland rides, road and rail verges and quite small areas of suitably rough grassland.

The preferred grasses are red fescue (Festuca rubra), which is thought to be an essential part of the larval diet, but sheep's-fescue (F. ovina), Yorkshire-fog (Holcus lanatus) and tor-grass (Brachypodium pinnatum) are also eaten.

Distribution

Photo above right by Chris Weston

The Marbled White is a fairly localised resident species in Yorkshire, and it is currently expanding its range. Numbers have increased nationally since the 1970’s.

Over 70 sites have been recorded in the past on the Wolds and typical habitats are found towards the heads of steep valleys, especially in the north Wolds; e.g. around Warter Wold, Millington and Bishop Wilton Wold. It also colonises disused railway tracks, e.g. the Hudson Way Leisure Trail and the disused railway at Wharram Percy, plus disused quarries like Kiplingcotes and Wharram, and even on the north-facing escarpment at Flixton Quarry, towards Filey. The species can also be seen on some roadside verges in the Wolds.

Aside from the Wolds, Marbled Whites can be found further north in Yorkshire, including Goathland and the Harrogate area, plus there is a colony at Shipley Station. Small colonies roughly follow the Magnesian Limestone ridge which runs up Yorkshire near the A1 and in fact the A1 with its grassy verges may help the butterfly spread. However it does not spread quickly because it prefers to stay in the same areas.

The species is dependent on the maintenance of grasslands, and colonies are damaged by tree planting or grassland scrubbing over. The growth of rabbit populations can also be a threat. Overall the species is helped by scrub and rabbit control plus very light grazing to maintain a suitable mix of fine and coarse grasses up to about half a metre tall.


The species’ international range is from north Spain up to northern areas of Britain, plus eastward through central and southern Europe into temperate Asia. It is also found in north west Africa, but not Scandinavia.

Life Cycle

There is one generation per year and adults are at their peak in July and early August although first emergence may occur as early as mid-June. Mating occurs in the open, and females appear to lay their eggs at random into the depths of suitably grassy areas. They perch on a stem or flower head, vibrate their abdomens, then take off and eject a green egg, which quickly turns white when exposed to the air.

Larvae, which are brown or green with a dark green stripe down their backs, hatch after about 20 days, eat their eggshells and go into hibernation. They usually awake in spring when weather is mild enough, but in mild winters, (usually in the south of England), this could be as early as January. They continue to feed on and off until they pupate in June and July. The fawn or brown coloured pupa are formed at ground level and look very rounded. The adults hatch after about three weeks in June or July.

Bright red spots can often be seen on the adult butterflies' bodies, which are the larval stages of red mites belonging to the Erythraedidae and Trombidiidae families.

Photo above by Chris Weston

Status

The species is not under threat.

Aberrations

This is a very variable butterfly with some 70 described aberrations ranging from all white to all black.

With thanks to The Butterflies of Yorkshire edited by Howard M Frost

C Jones 10/01/21