Climate change is causing a striking violet-blue butterfly from southern Europe to appear in record-breaking numbers across the south of England, wildlife charity Butterfly Conservation has revealed.

East Anglian Daily Times: Long-tailed blue (male) Picture: Neil HulmeLong-tailed blue (male) Picture: Neil Hulme (Image: Archant)

More than 50 long-tailed blue butterflies have been identified coming in from Cornwall right across to Kent, and as far north as Suffolk.

The Suffolk sighting was at Sizewell Beach, south of RSPB Minsmere last Saturday August 24.

The county's official butterfly recorder, Bill Stone, believes rising temperatures are behind the arrivals.

"The long-tailed blue is a long distant migrant and this is typical of a species adapting to climate change and expanding its range," said Mr Stone.

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"Its arrival coincided with a period of good weather, southerly winds and high pressure. We have only had one record of a sighting in Suffolk and it was seen only briefly, but I am happy that it was a long-tailed blue because it is quite distinctive.

"We are not seeing it here in the numbers that are being seen on the south coast where there has been quite a few eggs laid."

Found across southern Europe, Africa, Asia and Australia, the long-tailed blue gets its name from the wispy 'tails' on the trailing edge of each of its hindwings, which flutter in the breeze. Adjacent eye spots fool birds into thinking this is the head of the butterfly, allowing it to escape any attacks unharmed.

Typically, only a handful of these exotic migrants reach the UK each summer, but this is the third time in six years that the butterfly has arrived in vastly increased numbers nationally and 2019 looks set to surpass the previous peaks witnessed in 2015 and 2013, when five long-tailed blues were spotted in Suffolk.

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Butterfly Conservation's long-tailed blue expert, Neil Hulme, said: "We've never recorded this many migrant adults before - it's completely unprecedented. In only a few days, I've found more than 100 eggs in Sussex alone and the butterfly has been seen in Cornwall, Somerset, Devon, Dorset, Hampshire, Kent and Suffolk.

"The adults will keep laying eggs and in September and October we'll see the first British-born offspring emerging. I strongly believe this will take the total number seen this year to well over a hundred, breaking all previous records for this butterfly in the UK."