The adult painted lady is a medium to large orange-brown butterfly with beautiful markings. The forewings have black tips marked with white spots; the hindwings have rows of black spots. The undersides are mottled brown with pale blue eyespots. This butterfly can be found almost anywhere, especially on sites containing patches of thistles, the primary food plant of this species.

Behaviour

The painted lady’s metamorphosis process is a special feature of their growth. There are four stages in the process. Females lay their small, green eggs on a range of species, such as nettles and mallows, but thistles are the general favourite. When the caterpillars hatch (after about seven days) and grow, each constructs a ‘tent’ of folded leaves fastened with silk, allowing the caterpillar to hang upside down from a leaf.  Caterpillars pupate (after about two weeks) and remain suspended in a large ‘tent’ until the adults emerge (after about a week) in August and September. The whole British population dies, or emigrates to Africa in the autumn. It is unable to survive winters in the UK.

One factor contributing to its success is that the painted lady displays a unique system of continuous mating, throughout all seasons, including the winter. They reproduce throughout their migration. Equally important is the males’ exhibition of polygynous mating behaviour and the females’ ability to produce large numbers of offspring.

Female painted lady butterflies have been observed to have a relatively ‘high biotic potential’, meaning they each produce large numbers of offspring.

Size

• Wingspan: 5.8 – 7.5cm
• Average lifespan: Two-weeks as an adult butterfly

Status

According to a survey reported on the State of the UK’s Butterflies in 2015, the abundance of the painted lady has fallen by almost 85% between 2005 and 2014. However, over the long term, i.e. from the 1970s to 2014, both distribution and population trends show an increase.

Distribution

The painted lady migrates northwards from the desert fringes of North Africa, the Middle East, and central Asia, re-colonising mainland Europe and reaching Britain and Ireland. They breed whilst making this journey, so the ones that reach Scotland are offspring of individuals that arrived in Europe. Although this migration happens every year, on rare occasions conditions are such that they arrive in their millions, e.g., in 2019 across the UK and Ireland and 2009, when large numbers arrived in Scotland.

When to see

The first arrivals in south-west Scotland (following the main migration into the UK) occurs around the end of May – beginning of June. They may be seen into early October, depending on local weather conditions.

Facts

• Painted lady butterflies inhabit every continent except Antarctica and South America, making them the butterflies with the widest distribution of any species.
• The painted lady is an irruptive migrant, meaning that it migrates independently of any seasonal or geographic patterns. Evidence suggests that painted lady migrations may be linked to global climatic patterns, but are, in any case, highly erratic and do not occur every year.
• The painted lady is also known as the ‘thistle butterfly’ because thistle plants are its favourite nectar plant for food and the favourite food of the caterpillar.  In fact, its scientific name, Vanessa cardui, means ‘butterfly of thistle.’