Butterfly experts have been sharing their excitement after a species from southern Europe was confirmed to have been seen in the UK for the first time.

Two sightings of the Southern Small White have now been verified - one in Suffolk and one in County Durham.

It comes after the UK recorded its warmest and sunniest-ever spring, which has prompted a flurry of unusual butterfly and moth activity.

Dr Dan Hoare, Director of Nature Recovery at national charity Butterfly Conservation, said: "For us ecologists this is really exciting: it's always interesting when a new species turns up in the UK, but the Southern Small White has been gradually moving northwards through Europe for over a decade and we were just waiting for it to be seen in England for the first time. Top marks to the eagle-eyed snappers who not only got photos, but also realised the significance of what they’d seen.”

The Southern Small White, Pieris mannii, is a medium-sized butterfly that looks almost identical to the Large White and Small White found commonly across the UK. However, the Southern Small White can be distinguished by tiny differences in its black wing markings.

Until recently it was confined to southern and south-eastern Europe, then it started moving rapidly north-west at a rate of over 100km per year.

It was first found north of the Alps in France and in Germany in 2008, the Netherlands in 2015, and in 2019 was recorded near Calais in France.

Now it has been officially recorded in the UK.

The first sighting was made by birdwatcher Martyn Sidwell in Hartlepool Cleveland in County Durham on 1 July, and a second was spotted by William Brame at Landguard nature reserve in Suffolk on Saturday, 2 August. The latter sighting was verified by the chairman of Butterfly Conservation Europe Chris van Swaay, who has been tracking the species’ progress for years.

The caterpillars of the Southern Small White feed on a plant called candytuft which is popular with gardeners, and that could give the species a foothold to become a permanent resident in the UK.

The Southern Small White arrivals are among a host of striking butterfly activity which experts have linked to this year’s record-breaking weather.

In the spring, Butterfly Conservation recorded 18 species of butterfly emerging at least two weeks earlier than average, with a further 24 species at least a week early.

In Northern Ireland, Butterfly Conservation recorded more than 80 sightings of Comma butterflies - of which only a handful are seen usually. Furthermore, in the charity's Big Butterfly Count this year, reports of the exotic-looking Jersey Tiger moth - a species which just a decade ago was restricted to the Channel Islands and the south coast of England– have risen 78% on last year, with sightings as far north as Birmingham.

Dr Hoare added: “We always love to see butterflies and moths doing well in the UK, but we also know there are going to be winners and losers from the very rapid climate change we're experiencing.

“One way we can increase the number of climate winners is by managing habitats positively so that threatened species can benefit as well as widespread mobile species. That means creating and maintaining good quality, connected habitat at a landscape scale, which Butterfly Conservation has been doing for years and will continue to do.”