IN just three weeks this summer, nearly half a million Painted Lady butterflies were counted as part of the 10th UK-wide Big Butterfly Count - with 40,000 alone spotted in Wales.

Wildlife charity Butterfly Conservation said 2019 has been a ‘Painted Lady Year’ – a natural phenomenon that happens about once in a decade, when unusually high numbers of this migratory butterfly arrive in the UK.

In Wales, nearly 40,000 were spotted as part of the survey and four times more Painted Ladies were counted compared to the country’s next most abundant butterfly, the Peacock.

The Big Butterfly Count was run by Butterfly Conservation and sponsored by B&Q.

It is too early to tell how 2019 compares to the last ‘Painted Lady Year’ in 2009, but the numbers seen in Wales during this year’s Big Butterfly Count was around 25 times greater than in the 2018 survey, equating to an increase per count of 2126 per cent on the year before.

Several other common species have experienced a good summer, helped by the fine weather.

In Wales, the Meadow Brown experienced an impressive 147 per cent increase, while the Peacock had its best summer since 2014, with counts up 153 per cent on last year. There was also a 169 per cent rise in counts for the colourful red and black Six-spot Burnet moth.

The Small Tortoiseshell was the eighth most seen butterfly in Wales, but in the UK overall the species had its best Big Butterfly Count result in five years, with around 70,000 spotted across the UK this summer and counts of the species in Wales up 138 per cent on last year.

Despite this, scientists remain concerned about the Small Tortoiseshell’s long-term future as this once common and widespread butterfly has declined by 78 per cent across the UK since the 1970s.

Butterfly Conservation’s associate director of recording and research, Richard Fox, said: “Last year the Small Tortoiseshell experienced its worst summer in the history of the Big Butterfly Count, so to see its numbers jump up this year is a big relief. But what’s really interesting when we look at the new results is how this species performed far better in Scotland and Northern Ireland - where it was the second most seen butterfly during the count - but didn’t do nearly as well in Wales, where it only just made the top 10.

“We’re still trying to establish what is behind the long-term decline of the Small Tortoiseshell and while it’s good news that the butterfly fared better this summer, the poor results in Wales and southern England in particular suggest that climate change may be having more of an impact on this species than we have previously realised.”

This year across the UK more than 113,500 people took part in the Big Butterfly Count, the largest survey of its kind in the world, spotting nearly 1.6 million butterflies during the three-week, high-summer recording period.

Mr Fox said: “The Painted Lady obviously stole the show this summer, taking the top spot in Wales and in the UK overall, but 2019 has also been the most successful Big Butterfly Count in its 10-year history, with more people in Wales taking part and more counts being submitted than ever before.”

The warm weather experienced this summer should have helped most butterflies, but the common white species and blue butterflies all suffered slumps.

In Wales, the Large White, Small White and Green-veined White saw their numbers drop by 54 per cent, 55 per cent and 50 per cent respectively, compared to the same three-week period in 2018.

Last year the Common Blue recorded its best results across the UK since 2010 and was expected to do well again this year, but counts in Wales were down 61 per cent compared to 2018.

It is possible that the drop in sightings for some of these species could be the result of increased predation by parasitic wasps, populations of which may have been boosted by the butterflies’ good fortunes across the UK last summer.

The Big Butterfly Count results can be found at www.bigbutterflycount.org and these will be used by scientists to see how the UK’s common species are faring and where to target future conservation work.