The conker killer
Invading moth poses threat to horse chestnut trees
IT is a popular playground pastime enjoyed by generations of children – despite the efforts of health and safety officials.
But now conkers are under threat from a different quarter – a species of voracious moths.
The leaf-mining moth, which destroys horse chestnut trees, has been recorded for the first time in Scotland.
Scientists are so concerned about the bug that they have developed a mobile phone app to allow members of the public to record sightings, so they can track its progress.
The bronze and white- striped moth – Cameraria orhidella – is no bigger than a grain of rice, but its impact can be huge.
Its larvae ‘mine’ the leaves of horse chestnut trees, producing brown blotches that give the tree an autumnal appearance even in the height of summer.
The lack of greenery inhibits a tree’s ability to use the sun’s energy by photosynthesis and the seeds the tree produces will be small, shrivelled and definitely not ideal for a vigorous game of conkers.
A single tree can play host to a quarter of a million moths and the damage is essen- tially irreversible.
The leaf-mining moth first arrived in the south of England in 2002 and, by 2010, it had reached Newcastle.
Researchers believed the moth’s progress had halted until it was spotted at Loch Tay, in Perthshire, last year. They are now asking members of the public to use the LeafWatch mobile app so they can gauge its spread.
Dr Michael Pocock, organiser of the Conker Tree Science project and an ecologist at the UK’s Centre for Ecology and Hydrology, said: ‘The long-term prognosis for horse chestnut trees in the UK is not looking great.
‘Until recently Scotland was the place to go to see them in all their beauty all year round, but that could soon be a thing of the past.
‘New records of damage caused by the leaf-mining moth, from Scotland in particular, are really valuable to help us understand the way it is spreading.’
As yet, there is no known treatment for a tree that has been besieged by leaf-mining moths.
However, research suggests cleaning up leaf litter around the base of a tree can reduce the likeliness of a moth attack i n spring, as the insects have nowhere to bed down during winter.
Scientists are especially keen to protect the UK’s horse chestnut tree population as the species is not native to Britain and rarely regenerates naturally.
Sightings of the moth can either be submitted via the LeafWatch app or through the Conker Tree Science website.