Where are they found ? (in Britain and Ireland)
Around the coast in England, Wales, Ireland and Southern Scotland. Inland in the south-west and north of England.
What is their preferred habitat outside gardens?
Short, open grassland, often with bare stoney patches, is their preferred habitat and the wall is increasingly found in coastal areas on dunes, moorland, roadside verges, disused quarries and other wastelands.
Resident or migrant?
Resident
When to see them?
The butterflies appear in May to June, with a second generation from the end of July to August or September, depending on latitude. Occasionally, if the summer and autumn weather is suitable, there can be a small third generation in October. Males like to perch in territories and both sexes will bask on any bare surface, including footpaths and walls, from which they get their name. Females are much less conspicuous
What happens in winter?
Overwintering takes place as a caterpillar. The second generation of adults lay their eggs during August and early September and the caterpillars that hatch from these eggs grow more slowly than the earlier brood, entering hibernation in the autumn. Their hibernation is described as partial, which means they will feed at times throughout the winter when the weather is mild. Regular feeding begins again in the spring, followed by pupation then metamorphosis into the first generation of butterflies.
What do the early stages look like?
See the
UK Butterflies website for excellent pictures of the early stages. Spherical eggs are laid in small groups or singly on foodplant leaves. The caterpillars are green throughout their four
instars and grow in length from an average of 2.5mm to 25mm. They have many white hairs which become less obvious as the caterpillars grow. Feeding on their grass foodplants normally takes place at night but occasionally during the day. The green pupa is well camouflaged and hangs head-down from a silk pad secreted onto vegetation.
What do the caterpillars eat?
The caterpillars feed on a wide variety of grasses, but particularly cock's-foot Dactylis glomerata and annual meadowgrass Poa annua.1.
Flowers they take nectar from
The butterflies take nectar from many flowers, including garden varieties, but they particularly feed on
common fleabane, daisies, hawkweeds, knapweeds, ragged-robin, ragworts, thistles, water mint, wild marjoram, and yarrow.
2.
How are they doing?
The wall butterfly is not doing well. The 2022 State of UK butterflies report shows that its numbers have fallen by 86% since 1976, a figure which is almost unchanged from the 2015 version. The range, however, has continued to shrink and has declined by 87% in the UK overall since 1970, despite recent expansion in Scotland.3. This makes the wall one of the most severely declining butterfly species in the country and it is included on several “at risk” lists. The decline is most severe in Northern Ireland where it appears to be on the verge of extinction: there were no verified records there in 2023. The cause of the wall’s decline is not known.
Other interesting facts
In continental Europe (but not the UK) there are two other relatively common wall butterflies – the large wall Lasiommata maera and the northern wall Lasiommata petropolitana.4. The large wall has a similar continental distribution to the UK species and the two might easily be confused – the main distinguishing feature is that the forewings of the large wall are a darker orange. The northern wall has a more restricted distribution to Scandinavia and high mountains and is much darker in colour.
Rederences
4. European butterflies and moths
website
Page written by Judy Skinner, reviewed and compiled by Steve Head