RESUMO
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.
RESUMO
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.