The Tansy beetle is a beautiful green beetle that locally feeds exclusively on the Tansy plant. Although the plant is quite common the beetles are unable to fly making it difficult for them to colonise new areas and as a result they are now isolated in just a few small pockets – most notably alongside a stretch of the River Ouse near York.
As the Ouse is prone to flooding, scientists from the University of York our ecologists are now working together to establish a new population of the beetles on a recently discovered patch of Tansy alongside the Selby Canal. The new location won't flood and will provide a safe place for the beetles to thrive.
The beetle hasn't always been in such a perilous position, it was once more widespread and it's believed that the glittering green wing cases were used as decorations in much the same way as sequins are used today. Now, however, the beetle is endangered worldwide and, here in the UK, can only be found on a stretch of the Ouse as well as one other site in the Cambridgeshire Fens.
The main threat to the beetle has been a loss of appropriate habitat and this, coupled with their very poor ability to disperse, has meant populations have disappeared one-by-one. The Tansy plant on which both adults and larvae feed around York is also threatened by changes in land-use and the spread of invasive species such as Himalayan Balsam.
The giant panda of the beetle world
Dr Geoff Oxford, from the University of York, said; “Although the total beetle population around York often numbers in the thousands, one major summer flood on the River Ouse could exterminate the lot. We are therefore extremely grateful to the Canal & River Trust for offering us this site on the Selby Canal in which to establish an ‘ark' population of beetles which is safe from this threat.”
Phillippa Baron, ecologist for the Canal & River Trust said; “We're delighted to help in the efforts to protect these beautiful little beetles. They're like the giant panda of the beetle world so it's important that people step in to give them a helping hand and try to establish a healthy, growing population.
“They're such a gorgeous little beetle and it's a real shame to see them under threat so hopefully this new population will be just the start in their recovery.”
Around 50 captive-bred beetles are due to be released on the canal. The beetles feed solely on Tansy in Yorkshire and rarely venture from the plant so do not pose a threat to native species or agriculture.