While fire and wind cause damage to Irish forests, introduced fungal diseases and insect pests are the two greatest threats. Ash dieback – Chalara fraxinea and Phytophthora ramorum – have placed the future of ash and larch in doubt. As a result, ash and Japanese larch are no longer grant aided by the Forest Service.
Other species are also at risk but we rarely hear about them simply because they are not important forest trees. For example, Lawson cypress trees have been killed by the pathogen Phytophthora lateralis, while the introduction of the eucalyptus leaf beetle pest – Paropsisterna selmani – into Ireland poses a significant threat to our commercial foliage, wood biomass and processing industries.
When P. selmani was discovered in Kerry in 2007, it was largely ignored in forestry circles. At the time, eucalyptus was valued mainly for its decorative foliage but not as a timber producer.
Since then, Coillte and others have been carrying out research on a number of eucalyptus species exploring their potential as fast-growing fibre crops for wood energy and panel board production. It is also a species identified in the Forestry Programme 2014-2020.
Research
Now, researchers at Teagasc and University College Dublin are investigating the biological control of P. selmani. It originated in Australia, and is the first paropsine leaf beetle to become established in Europe, according to Teagasc.
Since its arrival in Kerry, it has spread to Cork and “in the last few months, new information indicates that this invasive pest has spread to Wexford and Wicklow,” a Teagasc spokesperson said. “Predictions of the patterns of spread suggest that it is only a matter of time before it is established throughout the island and this poses a bio-security risk to Britain and mainland Europe.”
Paropsine beetles feed off the leaves of trees, such as eucalyptus, although other species, including acacia, are seemingly not immune. According to the informative Australian Museum website, (http://australianmuseum.net.au), both the adults and larvae eat plant material and are extremely poisonous if eaten. “Adult beetles often have peck marks where birds have attempted to eat them but rejected them after tasting the poison.”
The colourful beetle defoliates eucalyptus trees and even small amounts of damage renders eucalyptus foliage crops unmarketable. In the absence of natural control, insecticide applications have been used by foliage growers, but Teagasc maintained “the unfortunate side effect of this is the disruption of the successful biological control of another invertebrate pest, a sap-sucking psyllid”. In any case, insecticides application is not an option in plantations for economic and environmental reasons.
“A parasitic wasp, Enoggera nassaui has been used as a biocontrol agent of similar leaf beetles in New Zealand and was imported into a quarantine insectary in University College Dublin – sponsored by Coillte – for further study,” said Dorothy Hayden, a lecturer at the Teagasc College of Amenity Horticulture, National Botanic Gardens. She is undertaking a PhD as a Teagasc Walsh Fellow, investigating the suitability of this egg parasitoid as a biocontrol agent for the leaf beetle in Ireland.
“The research will provide the necessary information to fulfil the requirements of a risk assessment, if a field release application is considered safe,” she said.
“Our research is investigating whether it is safe to release the biological control agent into Ireland. We are investigating its response to Irish weather conditions, its success in attacking the pest species and the extent to which it will only attack the pest species.”
The benefits of establishing a natural control agent for the beetle under field conditions include:
Retention of valuable market share and profitability for foliage growers.Growth of biomass and short rotation forestry. Resumption of biological control of the psyllid pest, where insecticides had been used. Positive environmental benefits. In a study of two paropsine beetles – coleopteran and chrysomelidae in south-eastern Queensland in 2006, Helen Nahrung stated: “Severe defoliation by paropsines can affect the growth rate, height, volume and possibly pulpwood quality of trees.” So far P. selmani is not causing sufficient damage to affect timber yields in Ireland.
Coillte has carried out its own research into frost resistant eucalypts and has identified a number of frost-hardy species.
Frost and prolonged cold periods have caused damage to a number of species, especially in inland areas in Ireland, since it was first established as a forest tree in 1908.
Eucalyptus has potential as a fast-growing fibre producer for energy and timber processing, as well as foliage, so Teagasc research into the control of P. selmani has been welcomed by Coillte and private plantation owners.
The Teagasc Forestry Development Department is holding two regional timber marketing days – ‘‘Talking Timber’’ – over the next two weeks in association with the Forest Service. These events are aimed at private timber growers, foresters, potential buyers and harvesting contractors. They are scheduled for:
Tuesday 26 August: Kildalton Agricultural College, Piltown, Co Kilkenny.Tuesday 2 September: Mullingar Park Hotel, Mullingar, Co Westmeath. ‘‘Talking Timber is an opportunity for farmers with timber for sale to meet prospective buyers,” said Liam Kelly of Teagasc. There are increased volumes of timber coming on the market this year due to the February storms, so Talking Timber is an opportunity for growers to meet representatives of sawmills, board mills and wood energy plants, as well as foresters and Teagasc advisers to discuss harvesting and timber sales.
Donal Whelan, technical director of the Irish Timber Growers Association (ITGA), will stress the need for comprehensive timber sales agreements between sellers and buyers.
He said that ITGA has launched a Master Template Tree Sales Agreement, which covers all the important points, and issues that must be addressed in such a contract.
“The agreement is written with the grower in mind and is available from the ITGA,” he maintained.
“It is hoped that the availability of this template, together with the ITGA Timber Sales Dispatch System, will encourage more growers to initiate thinnings by employing these standardised systems and bring much needed wood to market.”
The event is free but booking is required to secure a place.
Exhibitors and participants should contact Michael Somers (087-1216163), John Casey (087-2242283) or Liam Kelly (087-9090495) for further information or see the Teagass website (www.teagasc.ie/forestry/events).
While fire and wind cause damage to Irish forests, introduced fungal diseases and insect pests are the two greatest threats. Ash dieback – Chalara fraxinea and Phytophthora ramorum – have placed the future of ash and larch in doubt. As a result, ash and Japanese larch are no longer grant aided by the Forest Service.
Other species are also at risk but we rarely hear about them simply because they are not important forest trees. For example, Lawson cypress trees have been killed by the pathogen Phytophthora lateralis, while the introduction of the eucalyptus leaf beetle pest – Paropsisterna selmani – into Ireland poses a significant threat to our commercial foliage, wood biomass and processing industries.
When P. selmani was discovered in Kerry in 2007, it was largely ignored in forestry circles. At the time, eucalyptus was valued mainly for its decorative foliage but not as a timber producer.
Since then, Coillte and others have been carrying out research on a number of eucalyptus species exploring their potential as fast-growing fibre crops for wood energy and panel board production. It is also a species identified in the Forestry Programme 2014-2020.
Research
Now, researchers at Teagasc and University College Dublin are investigating the biological control of P. selmani. It originated in Australia, and is the first paropsine leaf beetle to become established in Europe, according to Teagasc.
Since its arrival in Kerry, it has spread to Cork and “in the last few months, new information indicates that this invasive pest has spread to Wexford and Wicklow,” a Teagasc spokesperson said. “Predictions of the patterns of spread suggest that it is only a matter of time before it is established throughout the island and this poses a bio-security risk to Britain and mainland Europe.”
Paropsine beetles feed off the leaves of trees, such as eucalyptus, although other species, including acacia, are seemingly not immune. According to the informative Australian Museum website, (http://australianmuseum.net.au), both the adults and larvae eat plant material and are extremely poisonous if eaten. “Adult beetles often have peck marks where birds have attempted to eat them but rejected them after tasting the poison.”
The colourful beetle defoliates eucalyptus trees and even small amounts of damage renders eucalyptus foliage crops unmarketable. In the absence of natural control, insecticide applications have been used by foliage growers, but Teagasc maintained “the unfortunate side effect of this is the disruption of the successful biological control of another invertebrate pest, a sap-sucking psyllid”. In any case, insecticides application is not an option in plantations for economic and environmental reasons.
“A parasitic wasp, Enoggera nassaui has been used as a biocontrol agent of similar leaf beetles in New Zealand and was imported into a quarantine insectary in University College Dublin – sponsored by Coillte – for further study,” said Dorothy Hayden, a lecturer at the Teagasc College of Amenity Horticulture, National Botanic Gardens. She is undertaking a PhD as a Teagasc Walsh Fellow, investigating the suitability of this egg parasitoid as a biocontrol agent for the leaf beetle in Ireland.
“The research will provide the necessary information to fulfil the requirements of a risk assessment, if a field release application is considered safe,” she said.
“Our research is investigating whether it is safe to release the biological control agent into Ireland. We are investigating its response to Irish weather conditions, its success in attacking the pest species and the extent to which it will only attack the pest species.”
The benefits of establishing a natural control agent for the beetle under field conditions include:
Retention of valuable market share and profitability for foliage growers.Growth of biomass and short rotation forestry. Resumption of biological control of the psyllid pest, where insecticides had been used. Positive environmental benefits. In a study of two paropsine beetles – coleopteran and chrysomelidae in south-eastern Queensland in 2006, Helen Nahrung stated: “Severe defoliation by paropsines can affect the growth rate, height, volume and possibly pulpwood quality of trees.” So far P. selmani is not causing sufficient damage to affect timber yields in Ireland.
Coillte has carried out its own research into frost resistant eucalypts and has identified a number of frost-hardy species.
Frost and prolonged cold periods have caused damage to a number of species, especially in inland areas in Ireland, since it was first established as a forest tree in 1908.
Eucalyptus has potential as a fast-growing fibre producer for energy and timber processing, as well as foliage, so Teagasc research into the control of P. selmani has been welcomed by Coillte and private plantation owners.
The Teagasc Forestry Development Department is holding two regional timber marketing days – ‘‘Talking Timber’’ – over the next two weeks in association with the Forest Service. These events are aimed at private timber growers, foresters, potential buyers and harvesting contractors. They are scheduled for:
Tuesday 26 August: Kildalton Agricultural College, Piltown, Co Kilkenny.Tuesday 2 September: Mullingar Park Hotel, Mullingar, Co Westmeath. ‘‘Talking Timber is an opportunity for farmers with timber for sale to meet prospective buyers,” said Liam Kelly of Teagasc. There are increased volumes of timber coming on the market this year due to the February storms, so Talking Timber is an opportunity for growers to meet representatives of sawmills, board mills and wood energy plants, as well as foresters and Teagasc advisers to discuss harvesting and timber sales.
Donal Whelan, technical director of the Irish Timber Growers Association (ITGA), will stress the need for comprehensive timber sales agreements between sellers and buyers.
He said that ITGA has launched a Master Template Tree Sales Agreement, which covers all the important points, and issues that must be addressed in such a contract.
“The agreement is written with the grower in mind and is available from the ITGA,” he maintained.
“It is hoped that the availability of this template, together with the ITGA Timber Sales Dispatch System, will encourage more growers to initiate thinnings by employing these standardised systems and bring much needed wood to market.”
The event is free but booking is required to secure a place.
Exhibitors and participants should contact Michael Somers (087-1216163), John Casey (087-2242283) or Liam Kelly (087-9090495) for further information or see the Teagass website (www.teagasc.ie/forestry/events).
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