The Panel on Plant Health conducted a pest risk assessment for Chrysanthemum stunt viroid (CSVd) and identified and evaluated risk reduction options, particularly those listed in Council Directive 2000/29/EC. Three entry pathways were identified, with plants for planting being the most important and rated as moderately likely. CSVd is recorded in some EU Member States with a limited distribution and is regulated on chrysanthemum; host plants are widely cultivated in greenhouses and outdoors. Therefore, establishment is very likely. Short-distance spread within a crop is likely, whereas short-distance spread between different species is unlikely to moderately likely. For vegetatively propagated species, in the absence of an efficient certification system, long-distance spread is very likely and a major impact would be expected on chrysanthemum, with associated yield and quality losses. However, under the existing certification scheme for chrysanthemum plant propagation material, the probability of spread through infected cuttings is largely reduced and the direct consequences of viroid outbreaks are expected to be minor. Minimal impact is predicted for other ornamental hosts and a minor impact for solanaceous vegetable crops. The indirect effects of CSVd are considered to be limited, with the exception of eradication. Risk reduction options addressing the sanitary status of the propagation material are likely to be the most effective and feasible. These include the current EU measures, as well as a statutory certification system with associated statutory import requirements or, failing that, but potentially less effective, the use of voluntary industry standards. It is difficult to disentangle the benefits of the current legislation from those of the industry-developed chrysanthemum certification system. The high efficacy of current measures is supported by the absence or limited presence of CSVd in the EU and by the limited number of interceptions and findings. Possible improvements to current measures are described and uncertainties discussed.

Augmentative biological control concerns the periodical release of natural enemies. In com- mercial augmentative biological control, natural enemies are mass-reared in biofactories for release in large numbers to obtain an immediate control of pests. The history of commercial mass production of natural enemies spans a period of roughly 120 years. It has been a successful, environmentally and eco- nomically sound alternative for chemical pest control in crops like fruit orchards, maize, cotton, sugar cane, soybean, vineyards and greenhouses. Currently, aug- mentative biological control is in a critical phase, even though during the past decades it has moved from a cottage industry to professional production. Many efficient species of natural enemies have been discovered and 230 are commercially available today. The industry developed quality control guidelines, mass production, shipment and release methods as well as adequate guidance for farmers. However, augmentative biological control is applied on a frustratingly small acreage. Trends in research and application are reviewed, causes explaining the limited uptake are discussed and ways to increase application of augmentative biological control are explored.

The Panel on Plant Health conducted a pest risk assessment for Liriomyza huidobrensis and Liriomyza trifolii in the European Union and identified and evaluated the phytosanitary measures listed in Council Directive 2000/29/EC. Entry on the principal pathways (plants for planting, cut flowers and leafy vegetables) is assessed as likely as the pests are regularly associated with the pathways at origin, survival during transport or storage is high and only partially affected by current pest management procedures, and transfer to a suitable host is likely as their hosts are so widespread. Establishment is rated as very likely because both species have established populations in most countries of the EU, with transient populations occurring outdoors in non-Mediterranean areas. Spread within the EU is considered to be likely because the pests can readily be moved with plant material. The magnitude of the potential consequences is rated as minor for both species in Mediterranean areas. In non-Mediterranean countries it is moderate for both species in protected crops but, outdoors, impacts are minor for L. huidobrensis and minimal for L. trifolii. The current regulations to prevent entry and spread were found to be only partially effective as interceptions are still being made, cut branches with foliage and leafy vegetables other than celery are excluded, and the methods for inspection and the treatments required to confirm pest free areas, places of production and consignments are not clearly specified. Removal of the legislation would have some advantages and disadvantages but may not have a major effect. The regulations could be tightened by including additional commodities, clearly prescribing the inspection procedures and the appropriate treatments to be used and combining these with other measures, e.g. screening. The application of protected zones to areas where the pests are not yet present can be applied to help prevent further spread.

International audience

EFSA guidance regarding pest risk assessment previously identified limitations within a generic qualitative risk assessment scheme published to support EU plant health decision making. In seeking to develop methods to overcome the limitations, we report results of a multiphase project where five test risk assessment methods were applied to Anoplophora glabripennis, Candidatus Phytoplasma pyri, Guignardia citricarpa, Meloidogyne chitwoodi, and Xanthomonas citri strains causing citrus bacterial canker. Teams of pest risk assessors applied the methods to the pests and compared methods in relation to EFSA PLH needs. The most promising method was then revised to incorporate desirable features from the other methods and tested on five more case study pests; Acidovorax citrulli, Ca.P. mali, Ca. P. prunorum, M. Fallax and Mycosphaerella dearnessii. In addition the risk assessment method that emerged from the EU funded project PRATIQUE was adapted to better suit EFSA needs and also tested on the second set of pests. Comprehensive datasheets on each pest were compiled to support the risk assessments. Datasheets included information that emerged from individual pest questionnaires distributed to the National Plant Protection Organisations of each EU Member State. Short term experimental studies were conducted to reduce uncertainty regarding survival and infectivity of the root-knot nematodes in the absence of host plants. Small scale experiments also clarified the role of vectors in the spread of Ca. Phytoplasma prunorum, proving that psyllids acquired the pathogen from wild Prunus sp. and transmitted it to orchards. Results from both sets of studies better informed the respective risk assessments and reduced some uncertainties although significant uncertainties still remain elsewhere within assessments. A novel method to determine an index of individual risk components, e.g. likelihood of entry, was developed. The performance of risk reduction options was evaluated by repeating assessments considering scenarios with and without risk reduction options in place. (Résumé d'auteur)

EFSA guidance regarding pest risk assessment previously identified limitations within a generic qualitative risk assessment scheme published to support EU plant health decision making. In seeking to develop methods to overcome the limitations, we report results of a multiphase project where five test risk assessment methods were applied to Anoplophora glabripennis, Candidatus Phytoplasma pyri, Guignardia citricarpa, Meloidogyne chitwoodi, and Xanthomonas citri strains causing citrus bacterial canker. Teams of pest risk assessors applied the methods to the pests and compared methods in relation to EFSA PLH needs. The most promising method was then revised to incorporate desirable features from the other methods and tested on five more case study pests; Acidovorax citrulli, Ca.P. mali, Ca. P. prunorum, M. Fallax and Mycosphaerella dearnessii. In addition the risk assessment method that emerged from the EU funded project PRATIQUE was adapted to better suit EFSA needs and also tested on the second set of pests. Comprehensive datasheets on each pest were compiled to support the risk assessments. Datasheets included information that emerged from individual pest questionnaires distributed to the National Plant Protection Organisations of each EU Member State. Short term experimental studies were conducted to reduce uncertainty regarding survival and infectivity of the root-knot nematodes in the absence of host plants. Small scale experiments also clarified the role of vectors in the spread of Ca. Phytoplasma prunorum, proving that psyllids acquired the pathogen from wild Prunus sp. and transmitted it to orchards. Results from both sets of studies better informed the respective risk assessments and reduced some uncertainties although significant uncertainties still remain elsewhere within assessments. A novel method to determine an index of individual risk components, e.g. likelihood of entry, was developed. The performance of risk reduction options was evaluated by repeating assessments considering scenarios with and without risk reduction options in place.

The application of pest risk analysis (PRA) decision‐support schemes, such as that used by the European and Mediterranean Plant Protection Organization (EPPO), generates many ratings for likelihood or magnitude of risk factors, each with an associated uncertainty. In accordance with the international standard ISPM 11 (FAO, 2004), questions have been devised to assess the key elements of pest risk in the four main sections of pest risk assessment: Entry, Establishment, Spread and Impact. After completing each section, risk assessors are required to give a summary rating and an uncertainty score for that section. The large number of question ratings and uncertainty scores make the task of summarizing each section and its uncertainty quite difficult. Two graphical tools have been developed to aid this task: the PRA Risk score and uncertainty visualizer (Visualizer) and the Rule‐based matrix model (RBMM). The Visualizer presents a case summary graph on a single page in such a way that the risk assessors and peer reviewers can see rating scores and uncertainties in a pictorial manner; the RBMM integrates all the individual questions in the assessment through a hierarchy of rules that attempt to mimic the logic used by the assessors and are arranged in the form of a flow chart to give an overall rating with an accompanying expression of uncertainty.

The application of pest risk analysis (PRA) decision-support schemes, such as that used by the European and Mediterranean Plant Protection Organization (EPPO), generates many ratings for likelihood or magnitude of risk factors, each with an associated uncertainty. In accordance with the international standard ISPM 11 (FAO, 2004), questions have been devised to assess the key elements of pest risk in the four main sections of pest risk assessment: Entry, Establishment, Spread and Impact. After completing each section, risk assessors are required to give a summary rating and an uncertainty score for that section. The large number of question ratings and uncertainty scores make the task of summarizing each section and its uncertainty quite difficult. Two graphical tools have been developed to aid this task: the PRA Risk score and uncertainty visualizer (Visualizer) and the Rule-based matrix model (RBMM). The Visualizer presents a case summary graph on a single page in such a way that the risk assessors and peer reviewers can see rating scores and uncertainties in a pictorial manner; the RBMM integrates all the individual questions in the assessment through a hierarchy of rules that attempt to mimic the logic used by the assessors and are arranged in the form of a flow chart to give an overall rating with an accompanying expression of uncertainty.

International audience | With the establishment of the Plant Health Panel in 2006, EFSA became the body responsible for risk assessment in the plant health area for the European Union (EU). Since then more than 70 outputs have been produced dealing with the full range of organisms harmful to plant health across all crop types and plants in the environment. There has been an increasing trend towards producing scientific opinions which are full pest risk assessments for the whole EU territory. In its work, and as a contribution to the wider development of risk assessment methodology, the Panel has developed a series of guidance documents. These deal with the peer review of existing pest risk assessments, a framework for conducting risk assessments which harmonise standards set by the International Plant Protection Convention and the legislative requirements of the EU, and extension of this framework to include environmental risk assessment and the evaluation of risk reducing options. Quantitative approaches have become increasingly important during this time. The Panel has developed such methods in climatic mapping (in association with the Joint Research Councils), application of spatial spread models, re-evaluation of quantitative pathway analyses, and in statistical modelling of experimental data. A Plant Health Network has been established to facilitate interaction with EU Member States, especially in relation to data collection and co-ordination of risk assessment activities. At the current time a revision of the EU Plant Health Regime is being formulated. The legislative consequences of the revision will be of considerable significance for the work of the Plant Health Panel.

<p>With the establishment of the Plant Health Panel in 2006, EFSA became the body responsible for risk assessment in the plant health area for the European Union (EU). Since then more than 70 outputs have been produced dealing with the full range of organisms harmful to plant health across all crop types and plants in the environment. There has been an increasing trend towards producing scientific opinions which are full pest risk assessments for the whole EU territory. In its work, and as a contribution to the wider development of risk assessment methodology, the Panel has developed a series of guidance documents. These deal with the peer review of existing pest risk assessments, a framework for conducting risk assessments which harmonise standards set by the International Plant Protection Convention and the legislative requirements of the EU, and extension of this framework to include environmental risk assessment and the evaluation of risk reducing options. Quantitative approaches have become increasingly important during this time. The Panel has developed such methods in climatic mapping (in association with the Joint Research Councils), application of spatial spread models, re-evaluation of quantitative pathway analyses, and in statistical modelling of experimental data. A Plant Health Network has been established to facilitate interaction with EU Member States, especially in relation to data collection and co-ordination of risk assessment activities. At the current time a revision of the EU Plant Health Regime is being formulated. The legislative consequences of the revision will be of considerable significance for the work of the Plant Health Panel.</p>