A rare beetle, which until five years ago was thought to have died out in Britain, has been discovered clinging on to a South Devon cliff-top.
Ecologists made the shock find of 45 Mediterranean oil beetles (Meloe mediterraneus) on a National Trust-owned cliff-top at Prawle Point, near Salcombe, this winter after one of the rare beetles was caught in a moth trap. The cliffs at Prawle, where light grazing by sheep and cattle has created a flower-rich habitat, is now one of only three known sites for the beetles.
The Mediterranean oil beetle was believed to be extinct in the UK, until a colony was found at the National Trust’s Bolberry Down, three miles west of Salcombe, in 2012.
Devon ecologist John Walters, who found the oil beetle colony at Prawle and rediscovered the species at Bolberry Down, said: “My friend David Grundy found a beetle in one of his moth traps in December. After I saw his pictures of the ‘mystery’ beetle online I raced to Prawle.
“The Mediterranean oil beetle only comes out at night, so it’s not easy scrambling around on the cliff looking for them. They’re unusual in that they are active during the winter, feeding off grasses and buttercup plants – their favourite food.
The parasitic beetles are totally reliant on solitary mining bees. As young larvae they crawl to the tops of plants, hitching a ride to the bees’ nests. There, the larvae will devour the bee’s egg and protein-rich pollen stores.”
The oil beetles have benefited from wildflower-rich areas that have emerged after grazing by cattle and sheep, National Trust rangers said. The conservation charity is working with its tenant farmers and partners to reverse wildlife declines.
Emma Reece, Area Ranger for the National Trust, said: “The amazing discovery of these beetles shows the importance of good conservation grazing.
“The solitary bees on which these oil beetles depend on spots of bare ground on sunny slopes where they can make their burrows. They were once a common sight, but more intensive farming practices have caused numbers to slump over the last century.
“By grazing the area lightly through the year our farm tenants at Prawle have created the perfect conditions for these rare insects. Rangers say they are working with tenant farmers and ecologists along the Devon coast to improve the clifftop habitats for rare wildlife like the oil beetle and solitary mining bees.
The National Trust plans to create 25,000 hectares of new ‘priority’ wildlife habitats across England, Wales and Northern Ireland by 2025.
(from a press release)