'Extinct' butterfly found in Cornwall

Conservationists had thought the White-letter Hairstreak was extinct in Cornwall

An endangered butterfly has been discovered at two sites in Cornwall more than 20 years after it is believed to have become extinct in the county.

A survey by Butterfly Conservation has found White-letter Hairstreak eggs at Torpoint and Tideford.

It was thought the species had been killed off by the Dutch Elm Disease outbreak in the early 1990s.

Butterfly Conservation Cornwall's, Andy Carey said it was possible the species had managed to "cling on".

According to the Wildlife Trust, the White-letter Hairstreak is estimated to have suffered a 99% population decline over the last 25 years in the UK.

The butterfly relies on Elm as its caterpillar foodplant but had declined across much of the UK following the "devastating impact" of Dutch Elm Disease.

Conservationists claim that the eggs found in south east Cornwall could suggest the butterfly may have moved from neighbouring colonies on the Devon side of the River Tamar.

Mr Carey said if it had managed to stay in Cornwall at all, it would have been "lurking around the tops of perhaps some quite remote Elm trees where it could well have clung on in a small focused colony".

Butterfly Conservation had been considering re-introducing the butterfly, not seen in Cornwall since 1991, and had called in experts to conduct egg surveys in selected areas.

Mr Carey said a couple of extremely experienced entomologists who were "really interested in this particular species" had "been out looking for it" and failed to find the White-letter Hairstreak, which is why it was thought to be extinct.

"The county is very large and it is very difficult to cover it all, and it's quite possible that it has been overlooked all this time."

Butterfly Conservation Cornwall said that this summer it would be making a "concerted effort" to get to as many Elm trees as possible to see how many more specimens could be found.