'Rare' caterpillar spotted in Clouts Wood wildlife reserve

A caterpillar from a threatened species of butterfly has been discovered at a wildlife reserve.

The white-letter hairstreak, Satyrium w-album, was spotted by a visitor at Clouts Wood, part of a Wiltshire Wildlife Trust site in Wroughton.

A trust spokeswoman said the caterpillars feed exclusively on flower buds and leaves of elm trees.

"The butterfly suffered heavy declines as a result of Dutch Elm disease in the 70s and 80s," she said.

"Unfortunately, this decline has continued, with a fall in the UK population of 55% in recent decades.

"Clouts Wood is fortunate to support a number of healthy mature wych elm trees, which provide fantastic habitat for the white-letter hairstreak."

The white-letter hairstreak is in flight between mid-June and mid-August.

It was given the name because of the W-shape etched in white on the underside of the hindwing.

The United Kingdom Butterfly Monitoring Scheme said there have been "significant declines" in numbers at monitored sites since 1976.