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PREPSYSlogo250.jpgThis multi partner project was focused on understanding how we can best prepare for, and manage if necessary, the risks and impacts of emerald ash borer (Agrilus planipennis) and bronze birch borer (Agrilus anxius). The project addressed key questions and gaps in our knowledge on the pests’ biology, control, dispersal and economic and environmental impacts.

The project was delivered by an international partnership which includes organisations from the UK, Netherlands, Ireland, USA and Austria.

Research objectives

The main objective of the project was to provide evidence to underpin contingency planning, policy development and policy communication through assessing the entry, establishment, spread, impact and management of the emerald ash borer (EAB) and bronze birch borer (BBB). The emphasis was on reducing the likelihood of their entry and establishment but also, in the worst case scenario, to provide evidence on how to cope should the pests succeed in establishing populations in Europe and the UK.

Please follow these links for further detail on the project’s objectives, work packages, a list of the project’s key research questions and the research findings and recommendations.

Related Resources

Forest Research and partners have produced a briefing note: “Threats to European trees from the emerald ash borer and bronze birch borer“. This report synthesises existing information on the topic, outlines the key research findings and presents a toolbox to help prepare for and manage emerald ash borer and bronze birch borer.

As the research was conducted under the banner of EUPHRESCO, a final project report was produced for them and published on the EUPHRESCO website.

Four team members visited Canada and US in the summer of 2017 to find out more about EAB management. An article was published about the trip. This article, titled “Preparing for an invasion“, first appeared in the autumn 2017 issue of Chartered Forester, the magazine for members of the Institute of Chartered Foresters. It is reproduced by kind permission of the Institute.

PREPSYS then held an international conference in Austria in 2018 (supported by the OECD). Details of the conference including the presentations are available on the BFW website. Following the conference, a special issue on emerald ash borer was published in the academic journal Forestry.

A number of presentations were also given to colleagues in the US and Canada:

Distribution and impact of emerald ash borer Agrilus planipennis (Coleoptera:Buprestidae) in the Moscow region of Russia and the threat to Europe

Preparing Europe for emerald ash borer and bronze birch borer: filling the knowledge gaps to prepare for the worst

Risk-based strategies to prepare for and manage invasive tree borers


PREPSYS started in October 2016 and the final report was published in May 2021.


Dr Mariella Marzano

Funders and partners

PREPSYS was funded through the international EUPHRESCO network, each funder pays for the participation of their own national researchers.

The Forest Research elements of the project were funded by Defra under the Future Proofing Plant Health programme.

The project partners were:


What’s of interest

Detailed project objectives

The project comprises six inter-related objectives that will address the issues associated with preventing and/or managing incursions by emerald ash borer (EAB) and bronze birch borer (BBB):

  1. To draw together the evidence base and best practice to inform policy on prevention of entry and/or spread of the two pests not currently in the EU. This will be led by Forest Research, UK.
  2. To assess the risks of invasions and consequent impacts of EAB and BBB to identify current best practice and evidence gaps. Led by NRC (National Reference Centre, Netherlands) with close liaison with partners and colleagues where the pests are currently present (either native or non-native): USA, China and Russia.
  3. To explore existing evidence on prevention and early detection to reduce the time lag between pest incursions and discovery. A key aim of this objective will be to assess ways to improve early detection. Led by BFW (by Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Austria).
  4. To improve scientific knowledge on how pests spread along pathways and establish in new locations. This will be led by Forest Research. Part of this objective will be to provide an initial exploration of the range of current management options and cost effectiveness in different contexts led by USDA (United States Department of Agriculture, USA).
  5. To develop improved understanding of the range of management options for current use and in the future alongside their cost-effectiveness and likely acceptance by society. This will be led by Forest Research. Bio-economic modelling for the assessment of short and long-term management actions will be led by BFW (Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Austria).
  6. To use available evidence to identify key stakeholders along pathways associated with EAB and BBB, existing communication networks and the policy landscape. Led by Teagasc (Agriculture and Food Development Authority, Ireland) and Forest Research.

The objectives will be delivered through six inter-related work packages.

Findings and recommendations

PREPSYS covers a range of responses required to safeguard European ash and birch trees from future threats. Some of the key findings are highlighted below:

  • The PREPSYS project conducted an extensive literature review and engaged with researchers and managers dealing with emerald ash borer (EAB) and bronze birch borer (BBB) to assess the ‘state of the art’ as a basis for potential invasion of Europe by these pests.
  • Although there is increasing information on the two pest species, further work especially from a European perspective is required to both anticipate and to react to incursions of the pests. The PREPSYS project addressed key questions and gaps in our knowledge on the pests’ biology, control (including risks from transport of firewood, treatment of infested ash and biological control agents), dispersal and economic/environmental impacts.
  • Using literature information and through an international conference held in Vienna, PREPSYS has pulled together the accumulated knowledge on EAB and BBB to prepare a European Toolbox for their detection and management. This can form the basis for a coordinated approach to deal with the very real threats from EAB and BBB.
  • It is known from North America and European Russia that there is usually a gap of several years between arrival and first detection of EAB. PREPSYS has assessed the range of options for survey and early detection of EAB or BBB and concluded that girdling of trees (stressing the trees) is the most effective for this purpose. However, there are logistic problems in using this technique and so use of traps with chemical lures is often more practical; a range of traps is available with similar efficiencies in capturing adult beetles, although none provide an accurate measure of beetle population size.
  • Management of infestations is usually through felling of infested or dead trees and this is an expensive and time-consuming procedure. Extensive research in North America indicates that slowing progress of infestations using trunk injections of the insecticide emamectin benzoate is an effective process to ‘buy time’ for selective felling and other measures. It is recommended that registration of the insecticide for use in Europe should be carried out urgently.
  • In the longer term, introduction of parasitoids (natural enemies) from the native ranges of EAB is now becoming more effective after a slow initial period following release of parasitic wasp species from China and Russia. There is also detailed knowledge of the climatic requirements of these classical biological control agents and this has improved establishment and efficacy. Since there is a need for assessment of possible adverse impacts on non-target species, tests for potential use of these agents in Europe should be carried out urgently. Methods for mass production are, fortunately, already developed in the USA.
  • Efforts to increase outreach and involvement of the local authorities and the public in detection and reporting of infestations should be increased. In particular, both hard-copy and on-line resources for Europe should build on the extensive knowledge base that has accumulated in North America. The scope for use of citizen science should also be investigated at local and national scales. Explanation of management measures (felling of infested trees, insecticide usage and release of natural enemies) should be enhanced to provide up-to-date information and encourage support by the public for such measures.
  • There is an increasing zone of overlap between EAB and ash dieback caused by the fungus Hymenoscyphus fraxineus in Western Russia. A key question is whether the interaction between the two organisms will affect total tree mortality. Support for joint research into this interaction should be provided urgently.
  • The tools for the toolbox are becoming more effective and sophisticated. However, there needs to be greater coordination and ‘ownership’ of the toolbox. EU DG Santé and EFSA, along with EPPO, are ideally placed to guide action plans and to provide financial and logistic support. National Plant Protection Organizations (NPPOs) can influence this process. Outcomes from PREPSYS have provided the key topics that could provide a management strategy for Europe. However, ownership of a future strategy in Europe remains at National levels and requires close coordination

Key research questions

The specific research questions that will be considered by partners include:

  • What are the potential risks and impacts of the two pests both in their countries of origin and where they have established in new locations?
  • What are the pathways for movement of the pests, and how can we better protect against the risk of introduction?
  • How can we improve early detection both on the pathways and at their end points?
  • What are the biological characteristics and pest population sizes that are likely to lead to successful breeding and establishment in a new location?
  • What are the rates of natural spread, and can we improve prediction of spread, both natural and by assistance?
  • How can we develop or improve cost-effective management and control approaches and tools (including biological control) and assess their social acceptability?
  • How can we best communicate and implement policy and engage with stakeholders (including policymakers, woodland owners and managers, academia and the public, importers and the wider nursery industry)?

PREPSYS – Work packages

The project comprises six work packages with inter-related objectives that, in parallel and consecutively, will address the issues associated with preventing and managing incursions by emerald ash borer (EAB) and bronze birch borer (BBB).

Work package 1: Project Management and Coordination (Lead: FR)

  1. Overall project management and coordination of delivery and results reporting.
  2. Establish website.
  3. Communication strategy.

Work package 2: Review evidence gaps relating to improved understanding of risks, impacts and how to mitigate them (Lead: NRC, Netherlands)

  1. Review and map current research/evidence and expertise.
  2. Review management approaches and their effectiveness, including biological control options.
  3. Identify and prioritise research and evidence needs (e.g. by analysis of existing state of the art and via a question-response tree) in the context of available funding and complementary ongoing work.
  4. Explore the potential risks and impacts and investigate how we can better protect against the risk of introduction on the main pathways and manage/adapt to these pests if they become established.
  5. Consider cumulative impacts of tree pests and diseases (e.g. Chalara and EAB).

Work package 3: Prevention and detection (Lead: BFW, Austria)

  1. Review current detection techniques and determine best option for future development to improve early and accurate detection.
  2. Consider need for:
    1. Laboratory and field-based molecular diagnostics (e.g. LAMP)
    2. Use of attractant lures (plant volatiles or potential pheromones),
    3. Use of sniffer dogs.

Work package 4: Natural and human assisted spread (Lead: FR and USDA)

  1. Assessment of the likely process and rates of natural spread of EAB and BBB.
  2. The cost-effectiveness of eradication, containment and management approaches under different scenarios.

Work package 5: Management (Lead: FR and Teagasc)

  1. Identify, assess and develop or improve cost-effective management and control approaches and tools (including biological control).
  2. Consider running bio-economic modelling related to outbreak management and looking into longer-term control methods which might include natural predators/BCAs and resistance breeding, including genetic conservation of native ash and birch species

Work package 6: Engagement (Lead: FR and Teagasc)

  1. Explore policy communication and implementation methods and consider ways to best engage with stakeholders on policy options in advance of post introductions and if the pests succeeds in establishing (including policymakers, woodland owners and managers, academia and the public, importers and the wider nursery industry).



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Mariella Marzano

Principal Social Scientist