Beetle from Asia poses threat to Ireland’s ash trees

British researcher warns up to 95% of Irish ash trees could be lost as a result of insect

Brian Dowling in his hurley workshop in Kilkenny. Photograph: Bryan O’Brien/The Irish Times

Brian Dowling in his hurley workshop in Kilkenny. Photograph: Bryan O’Brien/The Irish Times

 

Ireland’s ash trees, even if they manage to escape the ash “dieback” fungal disease, face an alarming threat from a beetle that is slowly moving westwards across Europe.

In the largest survey ever undertaken on the threats to ash trees, published by the Journal of Ecology, leading British researcher Dr Peter Thomas has warned that up to 95 per cent of them could be lost in coming years.

The emerald ash borer beetle, Agrilus planipennis, was accidentally introduced to North America in 2002.

It was found in Moscow in 2003, and has moved westwards since.

The beetle is “potentially far more serious than ash ‘dieback’,” according to Dr Thomas from the University of Keele in Staffordshire.

Under the bark

While the adult beetle, which feeds on ash leaves, does little damage, its larvae bores under the bark and into the wood, killing the tree.

Dr Thomas says the loss of ash will have a major impact.

“Over a hundred species of lichens, fungi and insects are dependent upon the ash tree and are likely to decline or become extinct if the ash was gone.”

The latest figures from Teagasc on the damage caused so far by ash “dieback” show 24 of the Republic’s 26 counties have been affected.

Cases have been recorded in native hedgerows in 12 counties and in roadside/motorway planting in 13 counties, while 115 forest plantations in 19 counties have been hit.

Millions of trees have been uprooted and buried both here and in Britain in an attempt to stem “dieback’s” spread.

Removing dead leaf litter slows down its progress since the fungus breeds there.

Research

However, there is no immediate cure for the twin threats of fungus and beetle, and Fine Gael MEP and former GAA president Séan Kelly has called on the EU to accelerate research to tackle the issue.

He said hurley makers have been largely dependent on imported ash due to a historical shortage of ash trees which was only addressed with planting in the last 20 years.

“These young plantations are now under threat, and imports from Europe will also be severely affected. A synthetic hurl is not nearly as flexible as the native ash.

“The hurley, along with the sliotar and harp, is a symbol of Ireland, and the hurl was recommended for geo-legal protection within the EU by the European Parliament. ”

“Dieback”, caused by the fungus Hymenoscyphus fraxineus, kills leaves, branches, and eventually the entire tree.

Both the fungus and the emerald ash borer beetle are native to Asia.

Flexible wood proved perfect for many uses

Coillte has stopped planting ash since the first case of “dieback” in Ireland was identified in Leitrim in October 2012.

Instead, the State forestry body, which is working closely with the Department of Agriculture to monitor and control the disease’s spread, is planting other broadleaves, such as sycamore and oak.

It said it was co-operating with Ireland Ash Society stakeholders, including the Irish Guild of Ash Hurley Makers, Teagasc and the GAA to “find a long term solution”.

Ash (Fraxinus excelsior) is native throughout Ireland and Britain and thrived on air pollution due to nitrogen’s ability to act as a fertiliser.

It is also tolerant of drought and copes well with climate change.

It is one of the most common species in hedgerows, with almost 100,000 km of it growing across Britain.

Used as far back as Neolithic and Mesolithic times as one of the best types of firewood, due to its oleic acid content creating a green flame, ash was a herbal medicine, a source of wattle, and provided wood for shipbuilding and musical instruments.

A relative of the European ash – the North American swamp ash – was used to make the 1950s Fender Stratocasters used by Buddy Holly, Jimi Hendrix and Hank Marvin of The Shadows.