One of the UK’s most highly threatened and unusual beetles has been discovered in a number of new locations in the Cotswolds thanks to an innovative conservation scheme.
The Rugged Oil Beetle, which is said to resemble a walking black olive, has been found in six new sites in Gloucestershire over the last year, following conservation work which is part of the Back from the Brink (BftB) project.
The beetle, which secretes a toxic oil from its legs to deter predators, is notoriously difficult to spot as it is restricted to just a handful of sites in Southern England and Wales and only comes out at night in late autumn and winter.
The Back from the Brink project, made possible thanks to The National Lottery Heritage Fund and People’s Postcode Lottery, aims to save 20 species from extinction and benefit over 200 more through 19 projects that span England.
Funding for the BftB project has paid for workshops in which volunteers have been trained to identify the beetles.
Over the autumn and winter these volunteers set out under the cover of darkness, armed with torches, to scour promising sites for the beetle.
Despite several fruitless searches, six new sites for the beetle were discovered taking the total number of Rugged Oil Beetle locations known in the Cotswolds to 17.
Jennifer Gilbert, BftB Cotswolds Community Engagement Officer, said: “The discovery of the new sites is very significant – originally only eight sites were known prior to 2017 so this has nearly doubled the number of known sites.
“This work will add to our knowledge about this species in terms of its habitat preferences and its behaviour. We can also now use this new information to not only tailor management to suit the beetle where it is found but also help the beetle to colonise new sites.”
The conservation work for the Rugged Oil Beetle is part of Back from the Brink’s Limestone’s Living Legacies project which aims to restore rare grassland habitats across the Cotswolds.
The scheme, led by Butterfly Conservation and with the support of partners including Buglife who ran oil beetle identification workshops, aims to improve habitats for threatened species including the Red-shanked Carder Bee, the Duke of Burgundy and Marsh Fritillary butterflies, Fly Orchid, Basil Thyme and the Greater Horseshoe Bat.
Butterfly Conservation’s Head of Conservation England, Dr Dan Hoare, said: “It’s been brilliant to harness the enthusiasm and skills of volunteers to shed some light on this enigmatic little beetle.
“It’s a great example of how Back from the Brink is advancing conservation for a wide range of species, from well know wildflowers and butterflies to lesser-known gems like this beetle, which is equally important in the ecological jigsaw.”
The Rugged Oil Beetle has an extraordinary life cycle, which relies on solitary mining bees. Adult female beetles lay thousands of eggs in an underground nest during the autumn and winter which hatch out in early April. These tiny beetle larvae, then climb onto a flower head and wait for a solitary bee to come to collect pollen and nectar.
The beetles then latch on to the bee’s fur and are transported into its underground nest where they spend the rest of the summer feeding on the bee’s stores of pollen and nectar before emerging as the adult beetle in the autumn.