Britain is bracing for a spectacular painted lady butterfly summer, with record-breaking numbers expected following heatwaves and favourable southerly winds. The migrant insects, characterised by their pale orange wings and frenetic flight, have been spotted in large numbers along the east coast, promising a colourful season.
Mass Arrival Underway
What is anticipated to be the largest arrival of painted lady butterflies in the UK for 17 years is now underway. Thousands, if not millions, of these butterflies have been carried northwards from sub-Saharan Africa, where they begin their journey each year. Successive generations breed in North Africa and the southern Mediterranean before reaching northern Europe later in the summer. In September, the offspring of these migrants fly south again.
In some summers, hardly any reach British shores. However, Butterfly Conservation experts report that a combination of favourable early spring conditions in southern Europe, the recent heatwave, and benign southerly winds have turned 2026 into a once-in-a-decade "painted lady summer."
Expert Insights
Dan Hoare, director of nature recovery at Butterfly Conservation, noted: "We've been seeing small numbers for the last three weeks, but it looks like there's been a big recent immigration from Europe over the past week, just as the hot spell collapsed. They grow extremely fast, feed easily, and fly really well. They've bred successfully in France and Spain during the heatwave and then had favourable winds to get them across the Channel."
Painted ladies can develop from egg to caterpillar to chrysalis and emerge as an adult butterfly in as little as four to six weeks in warm weather, allowing bumper generations to emerge swiftly.
Sightings and Identification
The butterflies have been seen in large numbers along the east coast into northern England this week. At Hickling National Nature Reserve near the Norfolk coast, 253 painted ladies were spotted feeding on a patch of bramble flowers. Many are faded grey "grandparent" butterflies that may have travelled directly from North Africa or southern Spain, while others are brighter orange short-haul travellers—the French-born offspring of the March and April arrivals into southern Europe.
Rare Moths and Other Species
The heatwave and southerly winds have also assisted an extremely rare moth, the eastern bordered straw, which has been found in moth traps across southern England. Striped hawkmoths are another rare and unusual arrival to look out for.
Painted ladies delight gardeners and farmers because their caterpillars devour a wide range of thistles.
Future Generations
In five or six weeks, a large British-born generation of painted ladies is likely to emerge—just in time for the world's largest citizen science insect count, the Big Butterfly Count, undertaken by 100,000 volunteers every July. "It feels like a real butterfly summer, and this big immigration could give us an even bigger brood in time for the Big Butterfly Count," Hoare said.
The painted lady's arrival en masse may prompt a late surge of voting in Butterfly Conservation's poll to find Britain's favourite butterfly. The painted lady could yet challenge the peacock butterfly for first place. "If the painted lady is your favourite, make sure you cast your vote," Hoare added.
