A very rare iridescent leaf beetle has been re-introduced to Wicken Fen nature reserve in Cambridgeshire in a joint project between The National Trust, Buglife and the Tansy Beetle Action Group (TBAG), with the support of government agency Natural England.
The tansy beetle (Chrysolina graminis) is currently in decline and under threat in the UK and across its worldwide range, and is a conservation priority species in England. Distinctive and eye-caching with a metallic appearance, the beetle was last seen at Wicken Fen 32 years ago and is currently known only from York and Woodwalton Fen, where it was rediscovered earlier this summer.
The beetle’s stronghold has been along a 30km stretch of the River Ouse, around York, where it mainly eats tansy (Tanacetum vulgare), a perennial herb which has given the beetle its name. It will also feed on water mint and gipsywort, which are both very abundant at Woodwalton and Wicken fens.
The tansy beetle has had a bumper year in York so there are many thousands of adults present. A few hundred have been released at Wicken Fen so they can feed up through the autumn on their food plants and then emerge from hibernation.
Stuart Warrington, a wildlife advisor for The National Trust, explains: “We don’t know exactly why this lovely beetle went extinct at Wicken Fen in 1982, but it may have been because the Fen was too dry and scrubby at that time. Lots of new habitat has been created or restored in recent years at Wicken, so we hope the beetle will find the site much more hospitable and will get firmly established.”
Vicky Kindemba, Conservation Delivery Manager for Buglife and co-chair of TBAG, said: “By spreading this rare species to new places, we hope to reduce the risk that the species will become extinct in the UK. But we want everyone to get involve with conserving this rare and beautiful creature. You can help by adopting a Tansy beetle through our website.”