Fighting back against unwelcome invaders which are capable of devastating trees in the British and Irish countrysides

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17 MARCH 2011NEWS RELEASE No: 14474

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The massive increase in world trade is having unintended consequences that are seriously affecting trees in the British and Irish countryside as deadly pests breach our border controls.

Tiny beetles and microscopic organisms are making their way across the world, hidden in the timber packaging that is used to transport imported goods of all kinds.

But potentially even more dangerous is the trade in live plants – exotics much desired by gardeners but which can bring with them foreign pests against which our own trees have little or no resistance.  

And while specialist plant health officers are ever vigilant at the borders, the sheer scale of trade means that inevitably some of the pests and pathogens make their way through, scientists and foresters were told at a symposium held by the IMPACT project.

The project - Integrated Management of forest Pests Addressing Climate Trends – is co-funded by the European Regional Development Fund (ERDF) through the Ireland Wales Programme (INTERREG 4A), COFORD and Forestry Commission Wales looking at tree pests and climate change.

The IMPACT team, which includes specialists from Forest Research in Wales, National University of Ireland, Maynooth and Swansea University, is assessing just how changing climate will influence the damage caused by pests and pathogens and are working to develop solutions against some of the key insect problems.

Meeting at NUI Maynooth, near Dublin for the symposium - Insect Pests of Trees: Meeting Future Challenges - the team was joined by local foresters and timber growers to review the latest information on pest problems facing forestry, and the preventative and control measures that can be taken.

“We have already seen the dramatic effects that imported pests can have on our forests,” said IMPACT project leader Dr Hugh Evans, Head of Forest Research in Wales. “As climate change continues to make our weather warmer and wetter, then the challenges will only increase.”

Although the IMPACT team is concentrating on insect pests - both native and introduced - that are likely to benefit from changing climate, the devastating effects of tree diseases were also emphasised at the Symposium.

Examples include the effects of Phytophthora ramorum, a fungus-like pathogen that is causing extensive damage and mortality to trees in the UK, including Wales, as well as Ireland.

Among the recent insect arrivals in Britain, horse chestnut leaf miner (Cameraria ohridella), which causes early leaf loss, can be traced back to Macedonia and was only discovered in the 1980s. It has spread rapidly across Britain and to the western edges of Wales. Thankfully, it has not yet reached Ireland, although the chances of its doing so are high.

Now the IMPACT project is investigating new ways of tackling these important pests which can have a dramatic effect on forests and woodlands across the UK and Ireland.

In its first 12 months, the project team has trialled the latest biological control measures against the large pine weevil, Hylobius abietis, and already has promising results in reducing its impact. The focus is on biological control integrated into novel monitoring regimes, concentrating especially on microbial control agents – fungi, bacteria, viruses and parasitic nematodes.

“The increasing extremes in our weather – hot or cold temperatures, increased rainfall and flooding – are creating the ideal conditions for forest pests either directly on their life cycles or through increased tree stress, making them less able to withstand pest attacks,” said Dr Evans.

“We also have to consider pest impacts when deciding which trees to plant if our forests are to be prepared for changing weather patterns. Conditions are even becoming difficult for Sitka spruce, our principal timber crop.

“Corsican pine is regarded as a more suitable species for the expected warmer, drier climates, but already the tree has been proven highly susceptible to the fungus causing red needle blight in the UK.”

The IMPACT partnership already has a strong track record in use of these agents and expects to deliver improved technology to landowners whose trees are at risk from pest infestations, now and in the future.

Contact: Dr Hugh Evans, Forest Research in Wales, tel 0300 068 0079.



Integrated Management of forest Pests Addressing Climate Trends - is a new project which is part-funded by the European Regional Development Fund (ERDF) through the Ireland - Wales Programme (INTERREG 4A) and part-funded by Forestry Commission Wales.

The project is led by Forest Research in Wales, a research unit launched in 2009 based at Aberystwyth, with the National University of Ireland at Maynooth and Swansea University. It runs for three years to 31 December 2012.

Forest Research

Forest Research is the research agency of the Forestry Commission. It is a world leader in the research and development of sustainable forestry and is Britain's principal organisation for forestry and tree related research, with specialists covering topics from managing timber, and protecting woodland from climate change, to tracking new pests and diseases, and examining the social and community benefits of woodland in urban and rural areas.

Forest Research in Wales

The newly established Forest Research in Wales unit, based in Aberystwyth, looks at research opportunities within Wales and elsewhere. Interactions with a wide range of stakeholders, particularly with Forestry Commission Wales and the Welsh Assembly Government, are being developed to scope and deliver research and appropriate technology transfer. Links with the research community in Wales, universities and government organisations are also being developed.

Forestry Commission Wales

About 14% of Wales is covered by woodlands. Of this, 38% (126,000 hectares/311,000 acres) is owned by the Welsh Assembly Government. Forestry Commission Wales is the Welsh Assembly Government’s department of forestry and manages these woodlands on its behalf.
More information on the woodlands of Wales is available on