Beetle species rediscovered after 86 years

The last record of the beetle was at Wicken Fen in 1938 by eminent coleopterist, Frank Balfour-Brown

A species of beetle has been rediscovered after a gap of 86 years.

The great silver water beetle was found in a trap at the Great Fen in Cambridgeshire by a researcher surveying for newts.

The last record of the species in the area was at Wicken Fen in 1938, according to monitoring and research officer Henry Stanier.

"I was staring down at a much bigger beetle nearly four centimetres in size and unlike the others, which are black and yellow, this was jet black and looking very different... that's when we got very excited," he said.

While it is aquatic, the great silver water beetle is not a true ‘diving’ beetle, but one of the many ‘scavenger’ water beetles

With the species having been in decline, Mr Stanier said its return "is a very positive move" for the nature reserve.

Despite never seeing one in the Great Fen before he knew exactly what the beetle was from the film of silver air cloaking its underside.

Like other freshwater invertebrates, it faced environmental threats, which make its appearance all the more exciting.

Mr Stanier said they had heard many sad stories about the loss of wildlife in the area and it was nice to hear this species had reached one of many wetland restoration sites in the region.

"They have conservation importance because invertebrates are part of the mosaic of life within reserves," he said.

"They make them function effectively, so having a new species, or rather species, return to the Great Fen is a very positive move."

He added: "It's possible that with climate change and warmer temperatures in certain cases they started to fly more readily and move inland.

"We are hopeful it is just one of a number of stepping stones for them to start colonising other areas as well."

The great silver water beetle can grow up to 4.8cm in size

Restoration projects are taking place at the Great Fen and conservationists said they would keep creating new habitats so these sorts of beetles could benefit.

The species has also turned up in moth-traps in Cambridgeshire such as in Sutton Gault by the Ouse Washes and near the River Great Ouse.

Dr Craig Macadam, Peterborough's Buglife Conservation director, said: "Fantastic to see this impressive water beetle at the Great Fen.

"Freshwater invertebrates are under threat from pollution, invasive non-native species, habitat fragmentation.

"The restoration work underway at the Great Fen will provide a huge fenland area which will benefit the Great Silver Water Beetle and many other invertebrate species.”

After it was caught and identified, Mr Stanier said the beetle was released back where he found it.