UK conker trees under threat from alien invading moths as scientists say Britain’s wasps are losing the insect war

Experts say there simply aren’t enough wasps to keep the horse chestnut-munching moths at bay

The UK’s conker trees are under threat because native insects are losing the war against an alien invader.

In less than three decades the horse chestnut leaf-mining moth, Cameraria ohridella, has spread from Greece to almost the whole of Europe, arriving on these shores around 10 years ago.

The moth, which burrows through the leaves of conker trees causing them to turn brown and die, was first spotted in south London in 2002 and can now be seen across almost the whole of England and Wales.

Experts had pinned their hopes on a species of tiny parasitic wasps, related to the larger black-and-yellow variety, which use the moth’s caterpillars to lay their eggs.

But a new reported published in the online journal Public Library of Science ONE revealed that the wasps are failing to keep up with the voracious appetites and seemingly unstoppable spread of their rivals.

In what has been hailed as a success for citizen science (if not for the conker trees), thousands of children across England and Wales were enlisted to record leaf damage and insect activity in their local area.

Volunteers were asked to find a visibly damaged – and therefore infested – horse chestnut leaf, seal it in a plastic bag for two weeks, and count the number and species of insects which emerged at the end.

A horse-chestnut leaf-mining moth which is winning an insect war in England and Wales A horse-chestnut leaf-mining moth which is winning an insect war in England and Wales Worryingly for the trees, the research revealed there were far fewer wasps than hoped, and not yet enough to slow the spread of the moths.

The study was designed to assess the impact of moths in a country where they had relatively recently arrived, and experts said there was still hope that wasp numbers might yet rally in response – as has been observed in other European countries.

Lead scientist Dr Michael Pocock, from the Centre of Ecology & Hydrology in Wallingford, Oxfordshire, said: “This is the sort of science that anyone can do.

“By taking part the public are doing real science - and the publication of this scientific paper is a demonstration of how seriously citizen science is now taken by the community of professional scientists.

“It seems almost like magic for children and other people to put a damaged leaf in a plastic bag, wait two weeks and then see insects - the adult moths or their pest controllers - emerge, but making these discoveries was a valuable contribution to understanding why some animals become so invasive.”

Co-author Dr Darren Evans, from the University of Hull, said: “This work could have been done by paying research assistants to travel the country and collect records, but by inviting thousands of people to get involved we, together, were able to pull this off much more cost-effectively.”

A total of 8,000 people took part in the Conker Tree Science project between 2010 and 2011.

Start your day with The Independent, sign up for daily news emails
Have you tried new the Independent Digital Edition apps?
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Clinical Lead / RGN

£40000 - £42000 per annum: Recruitment Genius: This is an exciting opportunity...

Recruitment Genius: IT Sales Consultant

£35000 - £40000 per annum: Recruitment Genius: This IT support company has a n...

Recruitment Genius: Works Engineer

Negotiable: Recruitment Genius: A works engineer is required in a progressive ...

Recruitment Genius: Trainee Hire Manager - Tool Hire

£21000 - £25000 per annum: Recruitment Genius: Our client is seeking someone w...

Day In a Page

Migrant crisis: UN official Philippe Douste-Blazy reveals the harrowing sights he encountered among refugees arriving on Lampedusa

‘Can we really just turn away?’

Dead bodies, men drowning, women miscarrying – a senior UN figure on the horrors he has witnessed among migrants arriving on Lampedusa, and urges politicians not to underestimate our caring nature
Nine of Syria and Iraq's 10 world heritage sites are in danger as Isis ravages centuries of history

Nine of Syria and Iraq's 10 world heritage sites are in danger...

... and not just because of Isis vandalism
Girl on a Plane: An exclusive extract of the novelisation inspired by the 1970 Palestinian fighters hijack

Girl on a Plane

An exclusive extract of the novelisation inspired by the 1970 Palestinian fighters hijack
Why Frederick Forsyth's spying days could spell disaster for today's journalists

Why Frederick Forsyth's spying days could spell disaster for today's journalists

The author of 'The Day of the Jackal' has revealed he spied for MI6 while a foreign correspondent
Markus Persson: If being that rich is so bad, why not just give it all away?

That's a bit rich

The billionaire inventor of computer game Minecraft says he is bored, lonely and isolated by his vast wealth. If it’s that bad, says Simon Kelner, why not just give it all away?
Euro 2016: Chris Coleman on course to end half a century of hurt for Wales

Coleman on course to end half a century of hurt for Wales

Wales last qualified for major tournament in 1958 but after several near misses the current crop can book place at Euro 2016 and end all the indifference
Rugby World Cup 2015: The tournament's forgotten XV

Forgotten XV of the rugby World Cup

Now the squads are out, Chris Hewett picks a side of stars who missed the cut
A groundbreaking study of 'Britain's Atlantis' long buried at the bottom of the North Sea could revolutionise how we see our prehistoric past

Britain's Atlantis

Scientific study beneath North Sea could revolutionise how we see the past
The Queen has 'done and said nothing that anybody will remember,' says Starkey

The Queen has 'done and said nothing that anybody will remember'

David Starkey's assessment
Oliver Sacks said his life has been 'an enormous privilege and adventure'

'An enormous privilege and adventure'

Oliver Sacks writing about his life
'Gibraltar is British, and it is going to stay British forever'

'Gibraltar is British, and it is going to stay British forever'

The Rock's Chief Minister hits back at Spanish government's 'lies'
Britain is still addicted to 'dirty coal'

Britain still addicted to 'dirty' coal

Biggest energy suppliers are more dependent on fossil fuel than a decade ago
Orthorexia nervosa: How becoming obsessed with healthy eating can lead to malnutrition

Orthorexia nervosa

How becoming obsessed with healthy eating can lead to malnutrition
Lady Chatterley is not obscene, says TV director

Lady Chatterley’s Lover

Director Jed Mercurio on why DH Lawrence's novel 'is not an obscene story'
Farmers in tropical forests are training ants to kill off bigger pests

Set a pest to catch a pest

Farmers in tropical forests are training ants to kill off bigger pests