A SITE in north Durham has become a nature reserve because of its rare butterfly population.

Durham Wildlife Trust and Butterfly Conservation have secured the lease for Longburn Ford Quarry, near Consett.

It has been acquired because of its population of small pearl bordered fritillary (Boloria selene) butterflies, a rare species in County Durham.

The organisations will manage the site to protect and enhance the colony of butterflies, by reinforcing their foodplant populations.

Fencing has been put up to enable visitors to enjoy the site - without putting the colony at risk from trampling and disturbance.

The controlled access will be complemented by interpretation and information panels. These will raise awareness of the small pearl bordered fritillary's existence, its plight and the management techniques necessary to ensure its survival.

The management regime has been made possible thanks to the support of Durham Wildlife Trust's members, who responded to an appeal to raise money for the site.

Richard Wood, chief executive of the trust, said: "I am delighted at this latest acquisition. It is an extremely important site for small pearl bordered fritillary butterflies, which are described in the Durham biodiversity action plan as 'a high priority butterfly for action'.

"One of the action plan's species targets is to acquire a site that can be managed for the benefit of the butterfly and we have realised that target."

Representatives of the trust, Durham County Council and Butterfly Conservation have been given a guided walk around the reserve.