‘Extinct’ in UK oil beetle rediscovered in Devon
‘Extinct' oil beetle discovery not seen since 1906
Mediterranean oil beetle (Meloe mediterraneus) © John Walters, Buglife
December 2012. A beetle hotspot on the South Devon coast has re-written the record books for the second time in six years with the discovery of an oil beetle which was has not been seen in UK since 1906 and was thought to have been extinct there for more than one hundred years.
Last seen in UK in 1906
Before its rediscovery, the Mediterranean oil beetle (Meloe mediterraneus) had been found in the South East of England in Essex and Kent. The beetle was last recorded in Kent in 1906, and had not been seen since, until rediscovered this autumn. Local naturalist John Walters found the oil beetle on National Trust land between Bolt Head and Bolt Tail on the beautiful south Devon coast, while carrying out a study for the charity Buglife - The Invertebrate Conservation Trust.
Leading beetle expert, Darren Mann of the Oxford University Museum of Natural History confirmed the discovery making this the first record in the UK for over 100 years, and the first ever for South West England.
John Walters said "The 2 to 3 centimetre long matt-black beetle resembles the rare Rugged oil beetle, but the beetles I found were much larger and their larvae were a different colour. I investigated further and was amazed to find that they were a ‘long lost' species!"
Andrew Whitehouse, Buglife's South West Manager said, "The rediscovery of this beetle is great news, bringing the total number of oil beetles species in the UK up to five. However all of our oil beetle species remain under threat. The loss of wildflower-rich habitats and the decline in wild bee populations, upon which these beetles depend, are the main threats to oil beetles in the UK. Buglife is working to better understand the needs of oil beetles and how best to conserve them"
Andy Foster, Biological Survey Team Leader at the National Trust, said: "This is remarkable news, following the discovery of the rare Short-necked oil beetle from the same area of south Devon only a few years ago, and demonstrates the value of detailed studies which can lead to such unexpected results. One can't help feeling there are other colonies out there just waiting to be found - it's crucial that we understand where these threatened species survive and understand more about their habitat requirements."
Buglife's national oil beetle conservation project is a partnership project with the National Trust and Oxford University Museum of Natural History and is funded through Natural England's Species Recovery programme.
To download a free oil beetle identification chart and report your oil beetle sightings visit the Buglife website www.buglife.org.uk/oilbeetles
Buglife's national oil beetle conservation project is a partnership project with the National Trust and Oxford University Museum of Natural History and is funded through Natural England's Species Recovery programme. The project was launched in 2011. Eight species of oil beetles have been recorded in the UK but three are thought to be extinct.
Two ‘Extinct in UK' beetles rediscovered
Two species that were thought to be extinct, the Short-necked oil beetle (Meloe brevicollis) and now, the Mediterranean oil beetle (Meloe mediterraneus), have now been rediscovered this century - both in south Devon. Both these species are now known from just one site in England however the Short-necked oil beetle was subsequently found on a site in Scotland.
The name ‘oil beetle' derives from the fact that the adult beetles are able to secrete a toxic oil called cantharadin from their leg joints. It is thought to repel predators. British oil beetles have declined due to habitat loss, changes in land management and a decline in solitary bee populations.
Oil beetle life cycle
Oil beetles are nest parasites of solitary ground-nesting mining bees that emerge in the spring. The adult oil beetles will lay up to 1000 eggs in a burrow in soft or sandy soil. The young larvae are unusual in being very active and long-legged and are known as triungulins after their three-clawed feet. They climb up flower stems and lie in wait for a suitable host bee. When a bee comes to collect pollen and nectar from the flower, the tiny triungulins grab hold of the hairs on the bee's back and are carried away to the bee's nest. There the louse-like triungulins drop off, eat the bees eggs and spend the rest of the year growing fat on the stores the bee collected for her own young.
Mediterranean oil beetle
One reason for the Mediterranean oil beetle (Meloe mediterraneus) remaining undiscovered was that specimens were mistaken for the similar-looking Rugged oil beetle (Meloe rugosus).
The adult Mediterranean oil beetle is slightly larger than the Rugged oil beetle, and has a larger thorax. The Rugged oil beetle also has a crease down the centre of the thorax that is absent in the Mediterranean oil beetle. The triungulins (larvae) are probably more distinct with the Mediterranean oil beetles being entirely orange whereas the Rugged oil beetle triungulins have a distinctly dark head.
More information on oil beetles can be found at www.buglife.org.uk/oilbeetles