A PIONEERING environmental project could tempt rare butterflies to return to a part of Sussex.

The rare White-letter Hairstreak, named after its white W-shaped streak on its brown wings and one of the smallest species of butterfly, has struggled to survive since the elm tree, its natural food source, was largely wiped out by Dutch elm disease, which took hold in this country in the 1970s.

Now 20 disease-resistant elm trees have been planted in Sompting Recreation Ground, Malthouse Meadow in Sompting, Lancing Manor Park and Shoreham’s Buckingham Park, in a bid to bring the butterfly back to the Adur district.

Liam Lord, Adur District Council’s arboricultural inspector, said: “We really hope these elm will encourage the Hairstreak to return.

“We haven’t seen it around here for a while but it loves flying among the leaves of the elm and we are keeping our fingers crossed.

“It’s really important we do everything we can to protect rare species and encourage biodiversity in our green spaces.”

The White-letter Hairstreak only grows to the size of a two pence coin and has an erratic spiralling flight, settling with its wings closed so its distinctive W streak is only visible in flight.

It is difficult to spot as it flies around the tops of trees, mainly elms.

After the Dutch elm disease epidemic, one of the only pockets of elm trees across the country to have stayed disease-free is in Brighton and Hove, where there was an intensive programme to stop its spread.

In 2007 there were sightings of the butterfly fluttering around the upper branches of two ancient elm trees in Preston Park, Brighton.

However, numbers of the White-letter Hairstreak have fallen and its survival is considered a ‘high priority’ by the charity Butterfly Conservation.

The environmental project has been carried out by Adur District Council, the Growing Communities project, South Downs National Park, and Butterfly Conservation. The trees were donated by South Downs National Park and planted by volunteers with the Growing Communities project, with expertise and land supplied by the district council at Sompting.

Councillor Emma Evans, the council’s executive member for the environment, said: “The biodiversity of our environment is so important, and while these projects might seem small, they are a vital part of the larger picture of conserving the plants and wildlife that enrich us all.”