What do they look like?
This is a very distinctive butterfly, with a chequerboard pattern of bright black and white markings on both wings, repeated on the underwing with grey-green replacing the black. The sexes are alike. Their overall white appearance make them easy to spot in a meadow. Wingspan male 53mm female 58mm
Where are they found (in Britain and Ireland)
Midlands and south of England, south Wales and Yorkshire. Absent from Scotland and Ireland
What is their preferred habitat outside gardens?
They live in unimproved grassland on downs and meadows, sometimes road verges and old railway lines. They are not common in gardens, recorded in under 10%.
Resident or migrant?
Resident
When to see them?
Marbled white adults are on the wing in mid-June to late July.
What happens in winter?
They overwinter as caterpillars, pupating from the middle of May
What do the early stages look like?
The eggs are pure white and almost spherical. They are dropped somewhat at random by the female. The newly emerged larvae stay hidden without feeding deep in the grass and start feeding in spring. Caterpillars are light green or pale brown. The dumpy pupa is at ground level or partly hidden in detritus, yellowish, darkening before hatching. There are excellent images of the early stages on the
UK butterflies website.
What do the caterpillars eat?
Sheep’s-fescue Festuca ovina, timothy grass Phleum pratense, cock’s-foot Dactylis glomerata , tor-grass Brachypodium pinnatum and Yorkshire fog Holcus lanatus among several other grasses1..
Flowers they take nectar from
Adults take nectar from clovers, knapweeds, thistles, wild marjoram (Origanum vulgare), wild thyme and yarrow2..
How are they doing?
The marbled white is doing relatively well, having increased recorded numbers by about 70% from 1976-2019. However, their range declined by about 10% over that period, although it had risen between1976-20143. .
Other interesting facts
It has been suggested that the very un-Satyrinae like colouration is a form of
Batesian mimicry in which the palatable (to birds) marbled white is mimicking the pierids or whites, which contain unpalatable strong cell-killing proteins as chemical defence, and so gains some protection
4. .
References
3. State of UK Butterflies
report
4. Brakefield M.B. et al (1992) Avoidance, concealment and defence. pp93-119 In: The ecology of butterflies in Britain Dennis, R.L (ed). Oxford Science publications
Page written and compiled by Steve Head