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International audience; The international seed trade is considered relatively safe from a phytosanitary point of view and is therefore less regulated than trade in other plants for planting. However, the pests carried by traded seeds are not well known. We assessed insects and fungi in 58 traded seed lots of 11 gymnosperm and angiosperm tree species from North America, Europe, and Asia. Insects were detected by X-raying and molecular methods. The fungal community was characterized using high-throughput sequencing (HTS) and by growing fungi on non-selective agar. About 30% of the seed lots contained insect larvae. Gymnosperms contained mostly hymenopteran (Megastigmus spp.) and dipteran (Cecidomyiidae) larvae, while angiosperms contained lepidopteran (Cydia latiferreana) and coleopteran (Curculio spp.) larvae. HTS indicated the presence of fungi in all seed lots and fungi grew on non-selective agar from 96% of the seed lots. Fungal abundance and diversity were much higher than insect diversity and abundance, especially in angiosperm seeds. Almost 50% of all fungal exact sequence variants (ESVs) found in angiosperms were potential pathogens, in comparison with around 30% of potentially pathogenic ESVs found in gymnosperms. The results of this study indicate that seeds may pose a greater risk of pest introduction than previously believed or accounted for. A rapid risk assessment suggests that only a small number of species identified in this study is of phytosanitary concern. However, more research is needed to enable better risk assessment, especially to increase knowledge about the potential for transmission of fungi to seedlings and the host range and impact of identified species.

Methodology of quantitative pest risk assessment developed by 2006 may be applied to CAPRA programme. The way of using this methodology when conducting PRA with CAPRA programme is provided in the paper including assessment of probability of entry of analysed pest to the PRA area, probability of its establishment there and potential economic impact.

Following a series of requests for scientific advice from the European Commission starting in 2013, the European Food Safety Authority (EFSA) conducted a pest risk assessment and created a comprehensive Xylella fastidiosa host plant database. The last update of the database, published in September 2018, includes information on host plants of both X. fastidiosa and X. taiwanensis, together with details on botanical classification, infection conditions, geographic location, pathogen taxonomy including information on subspecies, strain and sequence type, detection techniques, and tolerant/resistant response of the plant. This updated database of host plants of Xylella spp. reported worldwide provides a key tool for risk management, risk assessment, and research on this generalist bacterial plant pathogen.

The report is a supporting document of the pest risk assessment of Eotetranychus lewisi for the EU territory. This Annex A to the pest risk assessment of E. lewisi for the EU territory presents the preparatory work that was performed following the guiding principles and the stochastic model in a quantitative approach in the context of the EFSA risk assessment framework currently under development for Plant Health. Moreover, this pest risk assessment is performed in accordance to the principles described in the EFSA PROMETHEUS (PROmoting METHods for Evidence Use in Scientific assessments) project where recommendations are provided both for the systematic and reasoned search of the evidence required by the risk assessors and the use of such evidence in the risk assessment. PROMETHEUS is an organisational development project aiming to further improve the methods for "evidence use" (collecting, appraising and integrating data and evidence) in EFSA's scientific assessments and to increase their consistency., contact email: teamplh@efsa.europa.eu

Surveying multiple invasive pest species at the same time can help reduce the cost of detecting new pest invasions. In this paper, we describe a new method for mapping the relative likelihood of pest invasion via plant propagation material in a geographic setting. The method simulates the invasion of a range of pest species, including arrival in an uninvaded area, spread, and survival in a novel landscape, using information on the spatial and temporal distribution of the suitable host crop species and tentative knowledge of the spread and survival capacities of the target pests. The methodology is applied to a gridded map in which each map cell represents a site in a landscape. The method uses stochastic simulations to depict plausible realizations of the invasion outcomes and estimate the distribution of pest invasion likelihood for each cell in the area of concern. The method then prioritizes the cells based on the stochastic invasion outcomes using a pairwise stochastic dominance rule and a hypervolume indicator. We demonstrate the approach by assessing the relative likelihood of pest invasion for strawberry production in Finland. Our method helps to differentiate sites in a landscape using both the estimates of pest invasion risk and their uncertainty. It can be applied to prioritize sites for plant health surveys and allocate survey resources among large geographic regions. The approach is generalizable and can be used in situations where knowledge of the harmful pest species is poor or nonexistent.

This Guidance describes a two‐phase approach for a fit‐for‐purpose method for the assessment of plant pest risk in the territory of the EU. Phase one consists of pest categorisation to determine whether the pest has the characteristics of a quarantine pest or those of a regulated non‐quarantine pest for the area of the EU. Phase two consists of pest risk assessment, which may be requested by the risk managers following the pest categorisation results. This Guidance provides a template for pest categorisation and describes in detail the use of modelling and expert knowledge elicitation to conduct a pest risk assessment. The Guidance provides support and a framework for assessors to provide quantitative estimates, together with associated uncertainties, regarding the entry, establishment, spread and impact of plant pests in the EU. The Guidance allows the effectiveness of risk reducing options (RROs) to be quantitatively assessed as an integral part of the assessment framework. A list of RROs is provided. A two‐tiered approach is proposed for the use of expert knowledge elicitation and modelling. Depending on data and resources available and the needs of risk managers, pest entry, establishment, spread and impact steps may be assessed directly, using weight of evidence and quantitative expert judgement (first tier), or they may be elaborated in substeps using quantitative models (second tier). An example of an application of the first tier approach is provided. Guidance is provided on how to derive models of appropriate complexity to conduct a second tier assessment. Each assessment is operationalised using Monte Carlo simulations that can compare scenarios for relevant factors, e.g. with or without RROs. This document provides guidance on how to compare scenarios to draw conclusions on the magnitude of pest risks and the effectiveness of RROs and on how to communicate assessment results., This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2018.EN-1440/full ‘This guidance supersedes: a) the entire Guidance on a harmonised framework for pest risk assessment and the identification and evaluation of pest risk management options by EFSA. https://doi.org/10.2903/j.efsa.2010.1495; b) Sections 1.8 and 1.9 of Guidance on methodology for evaluation of the effectiveness of options for reducing the risk of introduction and spread of organisms harmful to plant health in the EU territory. https://doi.org/10.2903/j.efsa.2012.2755’

Following the 2014 EFSA’s Panel on Plant Health scientific opinion on the pest categorisation of the spider mite Eotetranychus lewisi, the European Commission requested the Panel to perform a pest risk assessment and evaluate the risk reduction options. A stochastic model was used to assess entry, establishment and spread and related uncertainties. In the EU, E. lewisi has only been reported to occur in Portugal (Madeira). Entry pathways assessed were strawberry plants for planting from the USA, poinsettia and raspberry plants for planting, and orange and lemon fruits from third countries. Entry is most likely via poinsettia. Under current EU phytosanitary requirements, there is around a one in ten chance that E. lewisi will establish outdoors over the next 10 years. Although unlikely, establishment would most likely occur in southern Europe where environmental conditions, temperature and host density, are most suitable. If E. lewisi did establish, pest spread is expected to be mainly human assisted, most likely the mite being transported long distances on plants for planting. Nevertheless, while remaining a regulated pest, spread would be slow and most likely confined to one NUTS 2 area after 10 years. Under a scenario with enhanced measures (pest free place of production) at origin, the Panel’s assessment indicate that it is extremely unlikely that E. lewisi would establish within 10 years hence spread is also extremely unlikely. The absence of trade of host plants from Madeira to other parts of the EU could explain why E. lewisi has not spread to other EU Member States. E. lewisi is reported as reducing yield and quality of peaches and poinsettia and is regarded as a growing concern for strawberry and raspberry growers in the Americas. The Panel concludes that should E. lewisi be introduced in the EU similar impacts could be expected.

Le 22 octobre 2014, le Parlement européen et le Conseil ont publié un règlement relatif à la prévention et à la gestion de l'introduction et de la propagation des espèces exotiques envahissantes (EEE). Ce règlement prévoit, en particulier àson article 19, que les États membres mettent en place des mesures efficaces de gestion vis-à-vis d'une liste d'EEE dites préoccupantes pour l'Union Européenne (UE) qui, selon l'article 4, doit être adoptée, par voie d'actes d'exécution, par la Commission européenne début 2016. Cette liste sera régulièrement révisée. Ainsi l'inscription d'une espèce dans cette liste se traduira par la mise en place d'actions de prévention et de lutte coordonnées entre les différents États membres de l'Union européenne, visant à réduire les impacts négatifs de ces espèces en premier lieu sur la biodiversité et les services écosystémiques ainsi que d'autres impacts négatifs éventuels dans le cas de certaines EEE pouvant entraîner des impacts sur la santé humaine et/ou des impacts économiques. Pour toutes les espèces qui seront proposées pour la future liste susmentionnée, la Commission européenne doit disposer d'une analyse de risques respectant 14 normes qu'eIle a fixées dans le rapport « invasive alien species -framework forthe identification of invasive alien species of EU concern. ENV.B.2/ETU/2013/0026 ››, ainsi que 5 critères définis à l'articIe 4 du règlement. Pour un certain nombre d'espèces listées dans le rapport suscité, des analyses de risques sont déjà disponibles. Pour celles n'y figurant pas et qu'un État membre souhaiterait voir proposer dans le cadre de la révision régulière de la liste (cf. Article 4), une analyse de risque est à fournir à la Commission européenne.Parmi les espèces végétales du genre Ambrosiaprésentes en France, plusieurs constituent des espèces exotiques envahissantes à impact potentiel pour la santé puisqu'elles émettent un pollen hautement allergisant pour l'homme. C'est le cas en particulier de l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), de l'ambroisie trifide (Ambrosia trifidaL.) et de l'ambroisie à épis lisses (Ambrosia psilostachyaDC.). Si pour l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), une analyse de risques est disponible dans le rapport susmentionné, tel n'est pas le cas pour l'ambroisie trifide.L'ambroisie trifide est également une adventice des cultures des plus difficiles à gérer dans sa zone d'origine, sa taille et son cycle de végétation induisant une concurrence forte avec la végétation en place. Elle a fait l'objet d'une fiche d'alerte de l'Anses en 2013 et les observations confirment son implantation en Midi-Pyrénées, sur des périmètres permettant encore d'envisager son contrôle.Par ailleurs, cette espèce est visée par plusieurs actionsdu 3èmeplan national santé-environnement (PNSE 3), en particulier l'action n°11 visant à mieux évaluer l'exposition à l'ambroisie et surveiller son expansion géographique, et l'action n°12 qui a notamment pour objectif de renforcer et de coordonner la gestion des espèces végétales et animales dont la prolifération peut être nuisible à la santé publique.Dans ce contexte et afin de pouvoir proposer également cette ambroisie lors d'une prochaine révision de la liste européenne susmentionnée, une analyse de risque concernant A. trifidasera réalisée en considérant comme aire géographique l'ensemble du territoire de l'Union européenne. Cette analyse de risques comprendra à la fois un volet évaluation des risques incluant les impacts sur la santé humaine et leseffets du changement climatique dans un avenir prévisible, et un volet gestion des risques, en suivant la méthodologie préconisée par la Commission européenne dans le cadre du règlement européen susmentionné.Afin de mettre en œuvre l'action n°12 du PNSE 3, l’expertise fournira également des recommandations visant à renforcer la gestion de cette espèce en France et améliorer la coordination des actions de gestion déjà mises en œuvre sur notre territoire.

Le 22 octobre 2014, le Parlement européen et le Conseil ont publié un règlement relatif à la prévention et à la gestion de l'introduction et de la propagation des espèces exotiques envahissantes (EEE). Ce règlement prévoit, en particulier àson article 19, que les États membres mettent en place des mesures efficaces de gestion vis-à-vis d'une liste d'EEE dites préoccupantes pour l'Union Européenne (UE) qui, selon l'article 4, doit être adoptée, par voie d'actes d'exécution, par la Commission européenne début 2016. Cette liste sera régulièrement révisée. Ainsi l'inscription d'une espèce dans cette liste se traduira par la mise en place d'actions de prévention et de lutte coordonnées entre les différents États membres de l'Union européenne, visant à réduire les impacts négatifs de ces espèces en premier lieu sur la biodiversité et les services écosystémiques ainsi que d'autres impacts négatifs éventuels dans le cas de certaines EEE pouvant entraîner des impacts sur la santé humaine et/ou des impacts économiques. Pour toutes les espèces qui seront proposées pour la future liste susmentionnée, la Commission européenne doit disposer d'une analyse de risques respectant 14 normes qu'eIle a fixées dans le rapport « invasive alien species -framework forthe identification of invasive alien species of EU concern. ENV.B.2/ETU/2013/0026 ››, ainsi que 5 critères définis à l'articIe 4 du règlement. Pour un certain nombre d'espèces listées dans le rapport suscité, des analyses de risques sont déjà disponibles. Pour celles n'y figurant pas et qu'un État membre souhaiterait voir proposer dans le cadre de la révision régulière de la liste (cf. Article 4), une analyse de risque est à fournir à la Commission européenne. Parmi les espèces végétales du genre Ambrosiaprésentes en France, plusieurs constituent des espèces exotiques envahissantes à impact potentiel pour la santé puisqu'elles émettent un pollen hautement allergisant pour l'homme. C'est le cas en particulier de l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), de l'ambroisie trifide (Ambrosia trifidaL.) et de l'ambroisie à épis lisses (Ambrosia psilostachya DC.). Si pour l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), une analyse de risques est disponible dans le rapport susmentionné, tel n'est pas le cas pour l'ambroisie trifide.L'ambroisie trifide est également une adventice des cultures des plus difficiles à gérer dans sa zone d'origine, sa taille et son cycle de végétation induisant une concurrence forte avec la végétation en place. Elle a fait l'objet d'une fiche d'alerte de l'Anses en 2013 et les observations confirment son implantation en Midi-Pyrénées, sur des périmètres permettant encore d'envisager son contrôle.Par ailleurs, cette espèce est visée par plusieurs actions du 3ème plan national santé-environnement (PNSE 3), en particulier l'action n°11 visant à mieux évaluer l'exposition à l'ambroisie et surveiller son expansion géographique, et l'action n°12 qui a notamment pour objectif de renforcer et de coordonner la gestion des espèces végétales et animales dont la prolifération peut être nuisible à la santé publique..

A new method for pest risk assessment and the identification and evaluation of risk-reducing options is currently under development by the European Food Safety Authority (EFSA) Plant Health Panel. The draft method has been tested on pests of concern to the European Union (EU). The method is adaptable and can focus either on all the steps and sub-steps of the assessment process or on specific parts if necessary. It is based on assessing changes in pest population abundance as the major driver of the impact on cultivated plants and on the environment. Like other pest risk assessment systems the method asks questions about the likelihood and magnitude of factors that contribute to risk. Responses can be based on data or expert judgment. Crucially, the approach is quantitative, and it captures uncertainty through the provision by risk assessors of quantile estimates of the probability distributions for the assessed variables and parameters. The assessment is based on comparisons between different scenarios, and the method integrates risk-reducing options where they apply to a scenario, for example current regulation against a scenario where risk-reducing options are not applied. A strategy has been developed to communicate the results of the risk assessment in a clear, comparable and transparent way, with the aim of providing the requestor of the risk assessment with a useful answer to the question(s) posed to the EFSA Plant Health Panel. The method has been applied to four case studies, two fungi, Ceratocystis platani and Cryphonectria parasitica, the nematode Ditylenchus destructor and the Grapevine flavescence dorée phytoplasma. Selected results from these case studies illustrate the types of output that the method can deliver., SCOPUS: ar.j, info:eu-repo/semantics/published

Le 22 octobre 2014, le Parlement européen et le Conseil ont publié un règlement relatif à la prévention et à la gestion de l'introduction et de la propagation des espèces exotiques envahissantes (EEE). Ce règlement prévoit, en particulier àson article 19, que les États membres mettent en place des mesures efficaces de gestion vis-à-vis d'une liste d'EEE dites préoccupantes pour l'Union Européenne (UE) qui, selon l'article 4, doit être adoptée, par voie d'actes d'exécution, par la Commission européenne début 2016. Cette liste sera régulièrement révisée. Ainsi l'inscription d'une espèce dans cette liste se traduira par la mise en place d'actions de prévention et de lutte coordonnées entre les différents États membres de l'Union européenne, visant à réduire les impacts négatifs de ces espèces en premier lieu sur la biodiversité et les services écosystémiques ainsi que d'autres impacts négatifs éventuels dans le cas de certaines EEE pouvant entraîner des impacts sur la santé humaine et/ou des impacts économiques. Pour toutes les espèces qui seront proposées pour la future liste susmentionnée, la Commission européenne doit disposer d'une analyse de risques respectant 14 normes qu'eIle a fixées dans le rapport « invasive alien species -framework forthe identification of invasive alien species of EU concern. ENV.B.2/ETU/2013/0026 ››, ainsi que 5 critères définis à l'articIe 4 du règlement. Pour un certain nombre d'espèces listées dans le rapport suscité, des analyses de risques sont déjà disponibles. Pour celles n'y figurant pas et qu'un État membre souhaiterait voir proposer dans le cadre de la révision régulière de la liste (cf. Article 4), une analyse de risque est à fournir à la Commission européenne. Parmi les espèces végétales du genre Ambrosiaprésentes en France, plusieurs constituent des espèces exotiques envahissantes à impact potentiel pour la santé puisqu'elles émettent un pollen hautement allergisant pour l'homme. C'est le cas en particulier de l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), de l'ambroisie trifide (Ambrosia trifidaL.) et de l'ambroisie à épis lisses (Ambrosia psilostachya DC.). Si pour l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), une analyse de risques est disponible dans le rapport susmentionné, tel n'est pas le cas pour l'ambroisie trifide.L'ambroisie trifide est également une adventice des cultures des plus difficiles à gérer dans sa zone d'origine, sa taille et son cycle de végétation induisant une concurrence forte avec la végétation en place. Elle a fait l'objet d'une fiche d'alerte de l'Anses en 2013 et les observations confirment son implantation en Midi-Pyrénées, sur des périmètres permettant encore d'envisager son contrôle.Par ailleurs, cette espèce est visée par plusieurs actions du 3ème plan national santé-environnement (PNSE 3), en particulier l'action n°11 visant à mieux évaluer l'exposition à l'ambroisie et surveiller son expansion géographique, et l'action n°12 qui a notamment pour objectif de renforcer et de coordonner la gestion des espèces végétales et animales dont la prolifération peut être nuisible à la santé publique..

In 2006, US Department of Agriculture Animal and Plant Health Inspection Service published a landmark rule providing generic radiation quarantine treatments. The rule approved radiation doses of 150 Gy for any tephritid fruit fly and 400 Gy for all other insects except the pupa and adult stages of Lepidoptera. The generic radiation treatments apply to all fresh horticultural commodities. Therefore, if a pest risk assessment demonstrates that no pupae or adult Lepidoptera are associated with a commodity, export approval can be forthcoming with no further research. Generic treatments are the culmination of decades of research but not an end point. Future research on quarantine and phytosanitary uses of radiation should focus on (1) development of specific doses for quarantine Lepidoptera not covered by the generic treatments, (2) reduction of dose levels for specific pests and commodities to shorten treatment time and minimize any deleterious effects of radiation treatment on commodity quality, (3) development of generic doses below 400 Gy for important groups of quarantine arthropods other than fruit flies, and (4) development of information on commodity tolerance and development of value-added irradiated fresh products using generic radiation treatments. Generic treatments will facilitate safe trade between countries that have approved phytosanitary uses of radiation for fresh agricultural commodities.

Le 22 octobre 2014, le Parlement européen et le Conseil ont publié un règlement relatif à la prévention et à la gestion de l'introduction et de la propagation des espèces exotiques envahissantes (EEE). Ce règlement prévoit, en particulier àson article 19, que les États membres mettent en place des mesures efficaces de gestion vis-à-vis d'une liste d'EEE dites préoccupantes pour l'Union Européenne (UE) qui, selon l'article 4, doit être adoptée, par voie d'actes d'exécution, par la Commission européenne début 2016. Cette liste sera régulièrement révisée. Ainsi l'inscription d'une espèce dans cette liste se traduira par la mise en place d'actions de prévention et de lutte coordonnées entre les différents États membres de l'Union européenne, visant à réduire les impacts négatifs de ces espèces en premier lieu sur la biodiversité et les services écosystémiques ainsi que d'autres impacts négatifs éventuels dans le cas de certaines EEE pouvant entraîner des impacts sur la santé humaine et/ou des impacts économiques. Pour toutes les espèces qui seront proposées pour la future liste susmentionnée, la Commission européenne doit disposer d'une analyse de risques respectant 14 normes qu'eIle a fixées dans le rapport « invasive alien species -framework forthe identification of invasive alien species of EU concern. ENV.B.2/ETU/2013/0026 ››, ainsi que 5 critères définis à l'articIe 4 du règlement. Pour un certain nombre d'espèces listées dans le rapport suscité, des analyses de risques sont déjà disponibles. Pour celles n'y figurant pas et qu'un État membre souhaiterait voir proposer dans le cadre de la révision régulière de la liste (cf. Article 4), une analyse de risque est à fournir à la Commission européenne. Parmi les espèces végétales du genre Ambrosiaprésentes en France, plusieurs constituent des espèces exotiques envahissantes à impact potentiel pour la santé puisqu'elles émettent un pollen hautement allergisant pour l'homme. C'est le cas en particulier de l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), de l'ambroisie trifide (Ambrosia trifidaL.) et de l'ambroisie à épis lisses (Ambrosia psilostachya DC.). Si pour l'ambroisie à feuilles d'armoise (Ambrosia artemisiifoliaL.), une analyse de risques est disponible dans le rapport susmentionné, tel n'est pas le cas pour l'ambroisie trifide.L'ambroisie trifide est également une adventice des cultures des plus difficiles à gérer dans sa zone d'origine, sa taille et son cycle de végétation induisant une concurrence forte avec la végétation en place. Elle a fait l'objet d'une fiche d'alerte de l'Anses en 2013 et les observations confirment son implantation en Midi-Pyrénées, sur des périmètres permettant encore d'envisager son contrôle.Par ailleurs, cette espèce est visée par plusieurs actions du 3ème plan national santé-environnement (PNSE 3), en particulier l'action n°11 visant à mieux évaluer l'exposition à l'ambroisie et surveiller son expansion géographique, et l'action n°12 qui a notamment pour objectif de renforcer et de coordonner la gestion des espèces végétales et animales dont la prolifération peut être nuisible à la santé publique..

Risks from intentional releases of organisms to agriculture, the food chain or the environment must be assessed to ensure proportionate planning, just as accidental releases from trade or natural spread must be predicted so that management can be organised. Pest risk assessment methods are well established for trade related introductions and it is efficient to build on these and adapt available risk assessment components from agricultural and environmental assessment tools. Some additional risk considerations, particularly related to the motivation, capacity and intended impact of a perpetrator should be included, and some key elements of trade related assessments, such as the volume of trade, may be irrelevant for intentional targeted releases. Risk levels from the various causes and impacts should be comparable to allow authorities to direct responses appropriately. Preventative actions, for both intentional and unintentional introductions, are particularly important. For intentional release this puts emphasis on motivation, capacity and sources. A scenario based approach to assessing intentional release risks is taken to develop a pest risk assessment tool that can cover the range of levels of potential activity. A risk assessment framework is illustrated and a range of example scenarios is described.

Quantitative models have several advantages compared to qualitative methods for pest risk assessments (PRA). Quantitative models do not require the definition of categorical ratings and can be used to compute numerical probabilities of entry and establishment, and to quantify spread and impact. These models are powerful tools, but they include several sources of uncertainty that need to be taken into account by risk assessors and communicated to decision makers. Uncertainty analysis (UA) and sensitivity analysis (SA) are useful for analyzing uncertainty in models used in PRA, and are becoming more popular. However, these techniques should be applied with caution because several factors may influence their results. In this paper, a brief overview of methods of UA and SA are given. As well, a series of practical rules are defined that can be followed by risk assessors to improve the reliability of UA and SA results. These rules are illustrated in a case study based on the infection model of Magarey et al. (2005) where the results of UA and SA are shown to be highly dependent on the assumptions made on the probability distribution of the model inputs.

Pest risk assessment studies are aimed at evaluating if weather conditions are suitable for the potential entry and establishment of an organism in a new environment. For fungal plant pathogens, the crucial aspect to be explored is the fulfillment of the infection process, that constitutes the first phase of the development of an epidemic as mainly driven by temperature and leaf wetness duration. This is of particular interest for climate change studies, because the modified pattern of temperature and moisture regimes could completely alter the known distribution and severity of plant disease epidemics. Biophysical process-based models could effectively be used in such studies, because they allow, within their applicability range, estimating organisms responses to climatic drivers in environmental conditions not yet experienced. One of the prerequisite of their adoption in operational contexts is a sensitivity analysis assessment aimed at understanding their ability (i) to differentiate the responses according to different parameterizations and (ii) to be sensitive to the variability of the input data. In this study, a generic potential fungal infection model simulating four pathogens chosen to provide a wide range in temperature and moisture requirements was analyzed. The model was run under diverse climatic conditions. The sensitivity of the model significantly changed according to the pathogen tested, and the relevance of its parameters in explaining model output resulted strongly linked to the environmental conditions tested, indicating its to be used in pest risk assessment studies.

Epitrix tuberis and E. cucumeris are major pests of potatoes in North America. E. tuberis causes the most serious damage because the larval feeding can cause superficial serpentine tunnelling on the surface of tubers as well as deeper pits. This damage can make crops unmarketable. By contrast, E. cucumeris mainly damages the foliage, and yield losses can occur when the adults reach high densities. In 2004, potato tuber damage characteristic of E. tuberis was seen in Portugal. In 2008, damage was more widespread and severe. E. cucumeris and a lesser known species, E. similaris, were recorded in affected fields. E. similaris has since been found across Galicia, Spain. E. similaris is thought to be the most likely cause of the tuber damage in Portugal, but it is possible that E. cucumeris or an as yet undetected Epitrix species is causing the damage. In 2010, a pest risk assessment for the Euro-Mediterranean area identified the movement of adults and pupae with seed or ware potatoes and associated soil as being the highest-risk pathways for the spread of Epitrix. In 2012, EU emergency measures were agreed to reduce the risk of further introductions and the rate of spread of these pests.

Liriomyza huidobrensis (Blanchard) is an economically important and highly polyphagous worldwide pest. To establish a temperature-dependent phenology model, essential for understanding the development and growth of the pest population under a variety of climates and as part of a pest risk analysis, L. huidobrensis life-table data were collected under laboratory conditions at seven constant temperatures on its host faba bean (Vicia faba L.). Several nonlinear equations were fitted to each life stage to model the temperature-dependent population growth and species life history and finally compile an overall temperature-dependent pest phenology model using the Insect Life Cycle Modeling (ILCYM) software. Liriomyza huidobrensis completed development from egg to adult in all temperatures evaluated, except at 32 °C, which was lethal to pupae. Eggs did not develop at 35 °C. Mean development time of all immature stages decreased with increasing temperature. Nonlinear models predicted optimal temperature for immature survival between 20–25 °C (32–38% mortality of all immature stages). Life-table parameters simulated at constant temperatures indicated that L. huidobrensis develops within the range of 12–28 °C. Simulated life-table for predicting the population dynamics of L. huidobrensis under two contrasting environments showed that lowland temperatures at the coast of Peru (250 m.a.s.l.) presented better conditions for a potential population increase than highland (3,400 m.a.s.l.) conditions. The presented model linked with Geographic Information Systems will allow pest risk assessments in different environmental regions to support the regulation of pest movement to prevent pest entry into not-yet invaded regions as well as to implement effective management strategies.

Dutch elm disease (DED) is a fungal disease that causes high mortality of elms. DED and its vector beetles are widely present in most of the countries in the Northern Hemisphere, but they are not known to be present in Finland. DED is a major risk to plant health in Finland. DED and its vectors are moderately likely to enter Finland by natural spread aided by hitchhiking, because they are present in areas close to Finland. Entry via other pathways is much less likely, mainly due to the low volume of trade of untreated wood and plants for planting. DED and its vectors could likely establish in the southern parts of the country, since they currently occur in similar climatic conditions in other countries. DED could cause massive environmental damage as natural elm groves are critically endangered habitats in Finland. The economic consequences to the owners of mature elms could also be significant. Eradication or containment of DED could be possible if strict measures were taken as the patchy distribution of elms would limit the spread of the disease. The most important source of uncertainty in this assessment is the lack of information regarding the amount of elm in fuel wood, wood waste and wood chips imported to Finland.

International audience

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 paper presents a model for quantifying quarantine-related phytosanitary measures by combining the two basic components of pest risk assessment—probability of establishment and economic effects—into a single management framework, iso-risk. The model provides a systematic and objective basis for defining and measuring acceptable risk and for justifying quarantine actions relative to acceptable risk. This can then be used to measure consistency of phytosanitary measures. The iso-risk framework is applied to APHIS-USDA phytosanitary risk assessments using a database of qualitative risk assessments and phytosanitary requirements for different agricultural and horticultural commodities. The results show that the APHIS-USDA risk assessment system produces assessments that are not consistent across a range of intermediate values for consequence or likelihood of occurrence.

Host area, potential pest impact and probability of pest presence are frequently displayed on maps by pest risk assessors. These variables can be mapped separately, but it is also important to map combinations of these variables in order to define the area of potential establishment and the endangered area to assist decision-making processes. This paper presents different methods for combining maps, and discusses their advantages and disadvantages. Different methods are shown that can be used to combine maps depending on whether the individual maps were derived from continuous quantitative variables or from discrete variables. The authors suggest combining maps derived from continuous variables using simple mathematical equations in order to compute expected invaded areas and expected potential impacts. Maps derived from discrete variables (e.g. scores) can be combined using a risk matrix, but the results may be highly dependent on the chosen matrix. The practical interest of these methods is illustrated in a case study on Diabrotica virgifera virgifera. The authors recommend combining the original continuous variables when such variables are available. The combination of categories defined from continuous variables led to a loss of information and may decrease the values of the maps. Risk matrices should be used only if the individual variables are discrete and if the underlying continuous variables are not available.

The phytosanitary risk associated with the movement of export-quality apple fruit to countries where fire blight does not occur is reassessed based upon additional data available since 1998 and clarification or correction of previously misinterpreted data present in the literature. The low epiphytic fitness of Erwinia amylovora (Ea) on apple fruit, the documented low incidence of viable Ea populations on mature apple fruit and the lack of a documented pathway by which susceptible host material could become infected from fruit-borne inoculum remain unchanged, and support the view that movement of Ea via commercial apple fruit is highly unlikely. With this new information, we updated a previously published model to re-estimate the likelihood of fire blight outbreaks in new areas because of commercial fruit shipment. This likelihood decreased in every scenario, and ranged from one outbreak in 5217 years to one in 753,144 years. By using the corrected and newly published data and by making assumptions based upon documented pathogen biology, the model gives more robust statistical support to the opinion that the risk of importing Ea on commercial apple fruit and the concomitant risk of establishing new outbreaks of fire blight is so small as to be insignificant.

The estimation of rates and patterns of spread is one of the key steps in a pest risk assessment. Pest risk analysts across the world wish to make quantitative, scientifically defensible assessments of likely spread by invasive alien species. However, data and time to develop detailed models for pest invasions are usually lacking and the resources to test those models in practice are not available. Therefore, generic and simple models are needed. A generic spread module composed of four models has been developed to assess the spread of plant pests. Four different models were developed to represent differences in objectives, available data and assumptions underlying the assessment of spread. The most complex of the models simulates spread in time and space and has four biological parameters, representing population growth and dispersal. The simplest of the models has only one parameter and considers only geographic range expansion. A third model assumes logistic growth of invaded area and a fourth model assumes logistic growth of population density in invaded cells. All models consider climatic suitability and presence of hosts. Consideration of economic value is optional. This chapter describes concepts and application of these models. They are illustrated by case studies for western corn rootworm, Diabrotica virgifera virgifera, in Europe.

The distribution and abundance of species that cause economic loss (i.e., pests) in crops, forests or livestock depends on many biotic and abiotic factors that are thought difficult to separate and quantify on geographical and temporal scales. However, the weather-driven biology and dynamics of such species and of relevant interacting species in their food chain or web can be captured via mechanistic physiologically based demographic models (PBDMs). These models can be implemented in the context of a geographic information system (GIS) to predict the potential geographic distribution and relative abundance of pest species given observed or climate change scenarios of weather. PBDMs may include bottom-up effects of the host on pest dynamics and, if appropriate, the top-down action of natural enemies. When driven by weather, PBDMs predict the phenology, age structure and abundance dynamics at one or many locations enabling the distribution of the interacting species to be predicted across wide geographic areas. PBDMs are able to capture relevant ecosystem complexity within a modest number of measurable parameters because they use the same ecological models of analogous resource acquisition and allocation processes across all trophic levels. The use of these analogies makes parameter estimation easier as the underlying functions are known. This is a significant advantage in cases where the biological data available to build an evidence base for pest risk assessment is sparse. Les modeles demographiques a base physiologique rationalisent l'identification et la collecte de donnees dans le cadre des evaluations du risque phytosanitaire fondees sur des preuves La repartition et l'abondance des especes qui causent des pertes economiques (c'est-a-dire les organismes nuisibles) dans les cultures, les forets ou le betail dependent de nombreux facteurs biotiques et abiotiques qui sont difficiles a separer et a quantifier sur des echelles geographiques et temporelles. Cependant, la biologie et la dynamique de ces especes, ainsi que d'autres especes qui interagissent dans leur chaine alimentaire ou leur reseau trophique, sont liees aux conditions climatiques et peuvent etre representees dans des modeles mecanistes demographiques a base physiologique (PBDM). Ces modeles peuvent etre appliques dans le cadre d'un systeme d'information geographique (SIG) pour prevoir la repartition geographique potentielle et l'abondance relative des especes en fonction des conditions climatiques observees ou de scenarios de changement climatique. Les modeles PBDM peuvent tenir compte des effets de l'hote sur la dynamique des organismes nuisibles et, le cas echeant, de l'action des ennemis naturels. Lorsqu'ils sont lies aux conditions climatiques, les modeles PBDM predisent la phenologie, la structure par âge et l'abondance a un ou plusieurs endroits, permettant ainsi de prevoir la repartition des especes en interaction dans de vastes zones geographiques. Les modeles PBDM sont capables de tenir compte de la complexite des ecosystemes a travers un petit nombre de parametres mesurables, car ils utilisent les memes modeles ecologiques de processus analogues d'acquisition et d'allocation des ressources a tous les niveaux trophiques. L'utilisation de ces analogies simplifie l'estimation des parametres car les fonctions sous-jacentes sont connues. Ceci est un avantage important dans le cas ou les donnees biologiques disponibles pour mettre en place des preuves pour l’evaluation du risque phytosanitaire sont peu nombreuses. Дeмoгpaфичecкиe мoдeли нa бaзe физиoлoгии yпpoщaют пoиcк и cбop дaнныx для oцeнки фитocaнитapнoгo pиcкa Pacпpeдeлeниe и изoбилиe видoв вpeдныx opгaнизмoв, пpичиняющиx экoнoмичecкий yщepб ceльcкoxoзяйcтвeнным кyльтypaм, лecaм и дoмaшнeмy cкoтy, зaвиcят oт мнoгиx биoтичecкиx и aбиoтичecкиx фaктopoв, кoтopыe cчитaютcя тpyдными для paзгpaничeния и кoличecтвeннoй oцeнки в гeoгpaфичecким и вpeмeннoм мacштaбe. Oднaкo, зaвиcимaя oт пoгoды биoлoгия и динaмикa тaкиx видoв и cooтвeтcтвyющиx взaимoдeйcтвyющиx видoв в иx пищeвыx цeпoчкax или ceтяx мoгyт быть пoняты c пoмoщью мexaниcтичecкиx ocнoвaнныx нa физиoлoгии дeмoгpaфичecкиx мoдeляx (PBDMs). Эти мoдeли мoгyт пpимeнятьcя в пpивязкe к Гeoинфopмaциoннoй cиcтeмe (ГИC), чтo пoзвoляeт пpoгнoзиpoвaть иx пoтeнциaльнoe гeoгpaфичecкoe pacпpeдeлeниe и плoтнocть пoпyляций c yчётoм cyщecтвyющиx пoгoдныx ycлoвий и cцeнapиeв измeнeния климaтa. PBDMs мoгyт включaть вoздeйcтвия pacтeния-xoзяинa нa динaмикy вpeднoгo opгaнизмa, a тaкжe, в cлyчae нeoбxoдимocти, пoдaвляющee вoздeйcтвиe ecтecтвeнныx вpaгoв. Ocнoвaнныe нa пoгoдe мoдeли PBDMs пoзвoляют cпpoгнoзиpoвaть фeнoлoгию, вoзpacтнyю cтpyктypy и динaмикy чиcлeннocти вpeднoгo opгaнизмa в oднoй или нecкoлькиx тoчкax, чтo дaeт вoзмoжнocть пpoгнoзиpoвaть pacпpeдeлeниe взaимoдeйcтвyющиx дpyг c дpyгoм видoв в paмкax бoльшиx гeoгpaфичecкиx зoн. Moдeли PBDMs мoгyт yчитывaть cлoжнocть экocиcтeм в пpeдeлax нeбoльшoгo чиcлa измepяeмыx пapaмeтpoв, т.к. в ниx oдни и тe жe экoлoгичecкиe мoдeли c aнaлoгичными пpoцeccaми пoлyчeния и pacпpeдeлeния pecypcoв пpимeняютcя для вcex тpoфичecкиx ypoвнeй. Иcпoльзoвaниe этиx aнaлoгий тeм лeгчe пoзвoляeт пpoизвecти oцeнкy пapaмeтpoв, чeм бoлee дocкoнaльнo извecтны бaзoвыe фyнкции, чтo пpeдcтaвляeт coбoй cyщecтвeннoe пpeимyщecтвo в тex cлyчaяx, кoгдa имeющиxcя биoлoгичecкиx дaнныx кpaйнe мaлo.

The invasion risk posed by the xylem feeding hemipteran, Homalodisca coagulata (native to the southeast USA and northeast Mexico, and a recent invader of California (USA) and Tahiti) and a xylem-dwelling phytopathogenic bacterium, Xylella fastidiosa (native to the Americas and causative agent of Pierce's disease of grape vines), was examined using the computer climate modeling program CLIMEX. Model predictions indicated that suitable climatic conditions for H. coagulata and Pierce's disease causing strains of X. fastidiosa exist in almost all grape production areas of the world, and H. coagulata may be able to colonize areas unsuitable for X. fastidiosa. Additionally, the model indicated that regions north of California will be unable to sustain populations of both pests because of cold stress, and that irrigation of agricultural and urban areas in California's deserts has removed dry stress limitations, which when combined with a depauperate natural enemy fauna most likely facilitated successful invasion by H. coagulata. CLIMEX predicted that cold stress accumulation would exclude Pierce's disease causing strains of X. fastidiosa from France and northern and central grape producing areas of Spain and Italy. This result is incongruous with Pierce's disease reports from Kosovo in the Balkans and may suggest that cold-tolerant strains of X. fastidiosa that cause Pierce's disease exist which could exhibit invasion potential and establish in areas of Europe contrary to results reported here.

The EPPO pest risk assessment scheme requires scores on a 1-9 scale to be assigned to 48 questions covering the potential for entry, establishment and impacts in a defined area. In this paper, we explore the extent to which the choice of scores can be assisted by providing descriptions for each number on the 1-9 scale. Such assistance would not only simplify the task faced by risk assessors, but also serve to standardize responses, thus enhancing the ability to compare the risks posed by different pests. We conclude that it is possible to provide descriptions for each score on the 1-9 scale for questions where assessments can be based on a numerical value. For questions which can only be answered with an expert opinion in the form of words, such as low, medium or high, only general guidance can be given.

Four main characters are associated with the potential of Lymantria dispar for international spread in ships moving from the Russian Far East to other Pacific countries: movement to light, wind dispersal of young larvae, length of egg stage, host range of larvae. Other Far Eastern lymantriid species have been scored for these characters on a 1-5 scale to provide an estimate of the risk of such international spread. Lymantria spp. score highest on this scale, and a few other lymantriids have scores indicating that there is a definite risk. Most of the species scored cannot, however, be adequately assessed for all the characters because of lack of information, indicating the need for further research before an adequate pest risk assessment can be done.

Increasing world trade in unmanufactured wood articles has amplified the risks of inadvertent introduction of pests into new environments. Previous introductions of non-native invasive organisms into the United States have resulted in severe outbreaks with economic and ecological disruption in forests. The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) and the USDA Forest Service have developed a pest risk assessment process that attempts to identify the risks associated with importation of unmanufactured wood articles. Assessments have been completed for importation into the United States of logs from Russia, New Zealand, Mexico, and South America. The results of these assessments are considered in developing regulatory approaches to preventing introductions of non-native invasive organisms.

The Panel conducted a risk assessment of Phyllosticta citricarpa for the EU. P. citricarpa causes citrus black spot (CBS) and is absent from the EU. Under the scenario of absence of specific risk reduction options against P. citricarpa, the risk of entry of P. citricarpa was rated as likely for citrus plants for planting and citrus fruit with leaves, moderately likely for citrus fruit without leaves, unlikely for citrus leaves for cooking and very unlikely for Tahiti lime fruit without leaves. Establishment was rated as moderately likely because susceptible hosts are widely available and environmental conditions in many EU citrus-growing areas are suitable (with high uncertainty) for P. citricarpa ascospore production, dispersal and infection. Current fungicide treatments will not prevent establishment. Environmental favourability is increased by the use of sprinkler and micro-sprinkler irrigation in some EU citrus-growing locations. Spread with trade was rated as moderately likely. Model results indicate that CBS epidemics are most likely to develop in EU citrus-growing areas in late summer to early autumn and in some locations also in late spring to early summer. CBS is expected to affect mainly lemons and late-maturing sweet orange and mandarin varieties, with moderate negative consequences for the production of fresh fruit, but with environmental impact of additional fungicide treatments. Negative consequences would be minor for early-maturing citrus varieties and minimal for citrus for processing. Uncertainty concerning the consequences is high, mainly because of the lack of data on critical climate response parameters for the pathogen but also because information on impact in areas at the limits of the current distribution is scarce. Since eradication and containment are difficult, phytosanitary measures should focus on preventing entry. Current phytosanitary measures are evaluated to be effective, with the exception of pest-free production sites.

The Panel on Plant Health assessed the risk to plant health from Phytophthora fragariae for the European Union and evaluated the current EU legislation and possible risk reduction options. The pest is present in most areas of Europe except southern Mediterranean regions. Entry through the plants for planting, but not seeds, pathway, is assessed as a major pathway, with the probability of entry rated as unlikely and the uncertainty as high. The probability of establishment is likely in the absence of existing disease control practices with low uncertainty. The probability of spread in the absence of a scheme for the production of certified plants for planting is considered to be very likely. With certification, spread is considered to be unlikely to moderately likely, depending on the inclusion of testing for the pathogen as part of certification. These ratings have medium uncertainty. Potential impact is rated as minor with medium uncertainty. The Panel evaluated the effectiveness of current EU legislation regarding the introduction and spread of P. fragariae. According to the regulation the import of Fragaria plants for planting, other than seeds, is prohibited from specified countries, whereas for import of these plants from other countries and for movement of these plants within the EU special requirements with respect to P. fragariae must be fulfilled. If the current legislation specific to P. fragariae were removed, no major consequences would be expected, unless the industry simultaneously ceased its voluntary certification activity. This is largely because of the important level of protection afforded to the industry by the widely used certification schemes for Fragaria, which significantly reduce the risks of entry, establishment, spread and impact. Certification schemes for the movement of Fragaria plants for planting offer the greatest efficiency and feasibility and the least uncertainty, especially if effective detection is incorporated into them.