British wasps could save conker trees from ‘alien’ moth


A species of wasp could save Britain’s beloved conker trees from destruction by an ‘alien’ moth, scientists believe.

The horse chestnut leaf miner moth arrived from Europe in 2002 and has spread rapidly through our conker trees causing serious damage.

The only hope of halting this decline is a species of tiny parasitic wasp, related to the larger yellow and black insects, which feed on the ‘alien’ moths.

Conservationists are now urging members of the public to take part in a national survey which is monitoring the spread of the miner moth.

Dr Darren Evans from the University of Hull, said: ”We are asking schoolchildren and members of the public to be our ‘lab assistants’.

”Parasitic wasps are vital pest controllers not only against these ‘alien’ moths attacking conker trees, but also for garden and farm insect pests.

”This is a real scientific study – we don’t know the answer but we are excited to see the results.

”Any alien species is a major threat to biodiversity because all organisms live in relation to each other and once an imbalance occurs, the whole system could begin to unravel.

”The horse chestnut leaf miner is just one example of how destructive an alien species can be.”

The horse chestnut leaf miner moth has caterpillars which live inside conker tree leaves, forming large patches of damage called ‘leaf mines’.

Although the moths do not kill the trees directly their leaf mines weaken the trees, which are then more susceptible to lethal diseases and produce smaller conkers.

Parasitic wasps, which are native to Britain, could save our conker trees by killing off the ‘alien’ moths.

The survey project is the largest of its kind in Britain and has been funded by the Natural Environment Research Council (NERC).

Dr Michael Pocock, from the University of Bristol, said: ”We need more help to fully understand how important these wasps are, and so we are asking any member of the public to get involved – all you need is a conker tree with the ‘alien’
leaf-mining moth.

”Pick a leaf this week, put it in a plastic bag and see what insects come out in two weeks time. It’s an easy, but important way to add to scientific knowledge.”

*To take part in the study please visit:


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