Keeping the tradition of conker contests alive – scientists battle with tree bugs (14-02-2012)A team of scientists in mid-Wales is working to make sure that the 2011 World Conker Championships to be held near Oundle, Northamptonshire on 9 October 2011 is just one of many more in the future.
Horse chestnut trees across the UK have been disfigured by attack from the larvae of Cameraria ohridella – better known as the horse chestnut leaf miner – since the first moth was found Wimbledon in 2002.
Now the IMPACT project - Integrated Management of forest Pests Addressing Climate Trends - is looking at new ways to prevent the spread of the pest which has already started attacking trees in Wales and is still spreading here.
“The leaf miner larvae currently do little permanent damage to the trees, although they progressively damage the leaves during the year, leading to the unhealthy autumnal appearance of heavily infested trees,” said Professor Hugh Evans, head of Forest Research in Wales, who leads the project which is part funded by Forestry Commission Wales.
The familiar appearance of the horse chestnut tree is threatened because the leaf miner disfigures the leaves as it feeds by ‘mining’ inside them and causing the leaves to go brown in late summer.
“'While the leaf miner does not kill trees, there is a serious bleeding canker disease that does,” said Professor Evans. “Our concern is that, combined with environmental effects arising from climate change, the two organisms will seriously affect this iconic tree in the future. These are further examples of the growing list of invasive organisms that have arrived on our shores and threaten our trees.”
Now the IMPACT team – made up of scientists and researchers from Forest Research in Wales, Swansea University and the National University of Ireland - has begun trialing new ways of combating the tiny larvae using natural agents such as nematodes and fungi.
Having collected live larvae from woodlands in the Swansea area, the project team is now working in laboratories at Aberystwyth University, where the main project office in Wales is located.
“IMPACT is about looking to the future, preparing for what might come under changing climates and through arrivals of new pests via international trade. We believe that by preparing for these threats through use of novel, environmentally benign solutions, we will be able to anticipate and manage pests such as the horse chestnut leaf miner and prevent them from becoming a real threat in the future,” said Professor Evans.
The adult leaf miner moth is 5mm long, with shiny, bright brown forewings with thin, silvery white stripes. It was originally first found in Macedonia in 1984 and has since travelled across Europe on the wind and by accidental transfer. It is still spreading from its original infestation in London and is now becoming more noticeable in Wales.