New populations of rare beetle discovered on Dartmoor

Tuesday 22nd November 2022

Invertebrate conservation charity Buglife is thrilled to announce that two new populations of one of Britian’s rarest beetles have been discovered in Devon.  The rare Blue Ground Beetle (Carabus intricatus) has been found at two new sites on Dartmoor – thanks to the efforts of Buglife staff, volunteers, and local naturalists.

Laura Larkin, Buglife Conservation Officer shared “Previously, the Blue Ground Beetle was only known from 13 sites in Devon, Cornwall and South Wales, so these new sightings are really significant, and they show how much we still have to learn about this magnificent beetle!

Up to 38mm in length, the Blue Ground Beetle is the UK’s largest ground beetle.  Given its name as a result of the beautifully marked and strikingly blue-coloured wing cases, the Blue Ground Beetle makes its home in damp, deciduous, often ancient, woodlands of Oak and Beech.  Both the adults and their larvae feed on slugs; upon finding their prey, the beetle will bite with its large jaws and inject digestive juices into the slug, eating it by sucking out its insides.

Blue Ground Beetles are mainly nocturnal and can be found all through the year, although they are most active and easiest to see from March to June, when adult beetles can be found clambering up mossy tree trunks under cover of darkness, in search of prey. Blue Ground Beetles can be easily confused with some of their smaller, more commonly seen relatives including the Violet Ground Beetle (Carabus violaceus); these beetles can be found throughout the UK, are smaller in size and more purple in their colouring. It would be highly unlikely to find a Blue Ground Beetle outside of its known range.

Buglife’s Dartmoor Blue Ground Beetle project was established to survey Dartmoor woods; seeking undiscovered populations of the Blue Ground Beetle.  Working with local volunteers and naturalist John Walters, the project team have spent many damp torchlit nights searching for the beetle.  The hard work and late nights have been rewarded with the addition of two new Blue Ground Beetle sites on Dartmoor during 2022.

Claire Hyne, from Papillon Gin who have funded the project said: “We are delighted to be able to provide funding for this important project on Dartmoor. It is very exciting that two new sites have been found this year. Great work from the Buglife team and volunteers”.

Richard Knott, Dartmoor National Park Authority’s Ecologist, said: “Dartmoor is of national importance for the Blue Ground Beetle, Britain’s largest and rarest beetle, and the combination of ancient valley woodlands and humid climate create the perfect conditions for slugs, which adults and larvae feed on. The discovery of these new sites is very exciting and indicates that Dartmoor habitats remain favourable for this rare and fascinating species.

There has been further excitement following a member of the public finding a deceased beetle whilst out walking near Bodmin Moor in Cornwall.

Tom Waters, who discovered the beetle said “‘I was genuinely thrilled to discover the Blue Ground Beetle in what is one of my favourite spots, and also very proud to be able to provide a new record for the beetle in Cornwall.

Laura Larkin added “These new Blue Ground Beetle records are really exciting. To find two additional sites on Dartmoor and realise that a third site in Cornwall is much larger than we originally thought are very significant for this very rare species. The fact that we now know of 15 UK sites is an incredible boost for these magnificent beetles, and there is still more work to do.”

If you’re interested in learning more about Buglife’s Dartmoor Blue Ground Beetle Project and would like to get involved please visit Dartmoor Blue Ground Beetle Project – Buglife projects