Spread of alien moth puts Britain's conker trees at risk

Latest research finds horse chestnuts from Cornwall to Yorkshire are now under attack

A A A

The future of Britain's conker crop is at risk from an "alien invader" that is attacking horse chestnut trees across the country. New research has found that the leaf miner moth, which weakens trees by making them shed their leaves early, is spreading faster than feared and has now hit as far west as Cornwall and as far north as the York moors.

Biologists fear the moth, first found in Greece, makes horse chestnuts more susceptible to the fatal bleeding canker disease, which causes trees to lose branches and bark and already affects more than half of all chestnut trees in some parts of the UK.

Nurseries have stopped planting horse chestnut saplings because there is no cure for infected trees – which means that as the trees die they are being replaced with different species. Great avenues of horse chestnuts, including one at Barrington Court, near Ilminster in Somerset, have already been cut down and replanted with a variety of oak.

Experts have compared the threat from the outbreak to Dutch elm disease, which all but wiped out Britain's elms in the 1970s. Guy Barter, the Royal Horticultural Society's chief adviser, said the leaf miner moth, which first emerged on a tree in a garden in Wimbledon, west London, in 2002, was "here to stay". He added: "In all likelihood there won't be an unaffected tree in Britain. It's unlikely there will be any way of remedying this infestation, which might render trees more susceptible to other problems like canker, which is potentially fatal." Michael Pocock, an ecologist at the University of Bristol who is studying the leaf miner outbreak, warned the moths "may cause trees to die prematurely".

Anne Frank's horse chestnut tree in Amsterdam, which she immortalised in the pages of her diary, was brought down by a storm in August. It suffered from an infestation of the moth and was also diagnosed with bleeding canker 10 years ago.

Mike Glover, the managing director of Barcham Trees, which plants more young trees than any other nursery in Europe, said he had stopped growing the most popular conker species, the white flowering tree found across Britain. "It's a complete disaster. They are so susceptible to disease that we just don't recommend them in any circumstance," he added. His nursery used to plant 5,000 conker saplings a year.

Mr Barter warned that conker games, including those due to be played at this Sunday's World Conker Championships near Ashton, Northamptonshire, might have to be played with "synthetic or virtual conkers" in the future. Organisers of this year's championships are already struggling to find enough conkers for the 450 competitors who travel from around the world to take part. A spokesman said they were short of at least 1,000 conkers and urged anyone within a 20-mile radius of Ashton to donate any decent ones that they could find.

The average conker has shrunk during the past few decades. Keith Flett, from the Campaign for Real Conkers, said conkers had halved in size during his lifetime. "Really large ones used to be about 2 inches [5cm] across; now on average we see a lot more that are about the size of a 10p piece, which is too small to be usable."

The leaf miner moth is spreading at a rate of around 40km (25 miles) a year. What most concerns scientists is that there is no natural predator. The RHS advises gardeners to collect and burn all the fallen leaves at the end of autumn to help to contain the outbreak because the moth pupae overwinter in the piles.

Have you tried new the Independent Digital Edition apps?
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Recruitment Genius: Sales Executive - OTE £40,000

£15000 - £18000 per annum: Recruitment Genius: This is a great opportunity for...

Recruitment Genius: Senior Designer / Design Director

£38000 - £48000 per annum: Recruitment Genius: This B2B content marketing agen...

Austen Lloyd: Law Costs HOD - Southampton

£50000 - £60000 per annum + Excellent Salary: Austen Lloyd: An outstanding new...

Recruitment Genius: Infrastructure Architect

£35000 - £45000 per annum: Recruitment Genius: An Infrastructure Architect is ...

Day In a Page

Syrian conflict is the world's first 'climate change war', say scientists, but it won't be the last one

Climate change key in Syrian conflict

And it will trigger more war in future
How I outwitted the Gestapo

How I outwitted the Gestapo

My life as a Jew in wartime Berlin
The nation's favourite animal revealed

The nation's favourite animal revealed

Women like cuddly creatures whilst men like creepy-crawlies
Is this the way to get young people to vote?

Getting young people to vote

From #VOTESELFISH to Bite the Ballot
Poldark star Heida Reed: 'I don't think a single bodice gets ripped'

Poldark star Heida Reed

'I don't think a single bodice gets ripped'
The difference between America and Israel? There isn’t one

The difference between America and Israel? There isn’t one

Netanyahu knows he can get away with anything in America, says Robert Fisk
Families clubbing together to build their own affordable accommodation

Do It Yourself approach to securing a new house

Community land trusts marking a new trend for taking the initiative away from developers
Head of WWF UK: We didn’t send Cameron to the Arctic to see green ideas freeze

David Nussbaum: We didn’t send Cameron to the Arctic to see green ideas freeze

The head of WWF UK remains sanguine despite the Government’s failure to live up to its pledges on the environment
Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

Author Kazuo Ishiguro on being inspired by shoot-outs and samurai

Set in a mythologised 5th-century Britain, ‘The Buried Giant’ is a strange beast
With money, corruption and drugs, this monk fears Buddhism in Thailand is a ‘poisoned fruit’

Money, corruption and drugs

The monk who fears Buddhism in Thailand is a ‘poisoned fruit’
America's first slavery museum established at Django Unchained plantation - 150 years after slavery outlawed

150 years after it was outlawed...

... America's first slavery museum is established in Louisiana
Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

Kelly Clarkson: How I snubbed Simon Cowell and become a Grammy-winning superstar

The first 'American Idol' winner on how she manages to remain her own woman – Jane Austen fascination and all
Tony Oursler on exploring our uneasy relationship with technology with his new show

You won't believe your eyes

Tony Oursler's new show explores our uneasy relationship with technology. He's one of a growing number of artists with that preoccupation
Ian Herbert: Peter Moores must go. He should never have been brought back to fail again

Moores must go. He should never have been brought back to fail again

The England coach leaves players to find solutions - which makes you wonder where he adds value, says Ian Herbert
War with Isis: Fears that the looming battle for Mosul will unleash 'a million refugees'

The battle for Mosul will unleash 'a million refugees'

Aid agencies prepare for vast exodus following planned Iraqi offensive against the Isis-held city, reports Patrick Cockburn