Painted Lady - Vanessa cardui

The Painted Lady is a long-distance migratory butterfly that is easily recognised by its orange and black patterns and white spots. Travelling all the way from North Africa and the Middle East, the return of this large butterfly is a welcome indicator of summer ahead.

Habitat

They are to be found in a range of habitats in Wiltshire, and seem to prefer open areas with good populations of thistles which are the main foodplants of the caterpillars and provide nectar for the adults.

Description

The open wings have a striking pattern and colouration; the upper wings are a pale orange background colour, the forewings have black tips with white spots, the hindwings have rows of black spots. The undersides of the wings are paler with blue eyespots.

Caterpillars are usually 3cm in length with a dark body with white spots. They have yellowish-black spines, and a yellow stripe along each side.

Biology

Each year, the Painted Ladies long-distance migration causes the most spectacular butterfly migrations observed in Britain and Ireland. It spreads northwards from North Africa reaching Britain and Ireland. Numbers peak in late summer and in some years it is an abundant butterfly.

The pale-green eggs are laid singly on the upperside of leaves of the foodplants. The caterpillar hatches after around a week, and spins a silk pad on the underside of the leaf on which it feeds; lastly a tent of leaves is made in which the chrysalis develops. They pupate inside these shelters, and the adults emerge after around two weeks.

Several generations may occur in hot summers, but as the weather deteriorates, all caterpillars, chrysalises and adults perish. There is no evidence that Painted Ladies can overwinter in Britain in any of its life stages, the whole British population dies or emigrates to Africa in the autumn.

Adults can be seen from May to October, caterpillars from May to September.

A wide range of foodplants may be used, with thistles being preferred. Mallows, Common Nettle, Viper's-bugloss, and various cultivated plants also have been recorded as larval foodplants.