Guidelines for statistically sound and risk‐based surveys of Xylella fastidiosa

At the request of the European Commission, EFSA prepared specific guidelines for the survey of Xylella fastidiosa to guide the survey or through the design of statistically sound and risk-based surveys, integrating the key biological information. Based on examples, three different survey designs are simulated: detection surveys to substantiate pest freedom, delimiting surveys to determine the boundaries of an infested zone, and buffer zone surveys to monitor a zone ensuring pest detection at a low level of prevalence. The first step of the survey design consists of setting out the aims of the survey, characterising the host plant population and the methods used to identify the pest. All the survey parameters are quantified considering the importance of the related assumptions. The more accurate the information used to select/estimate the survey parameters, the more robust the conclusions of the survey will be. The second step of the survey design consists of the sample-size calculation using the survey parameters as inputs forthe statistical tool (RiBESS+). The last step of the survey design is the allocation of the samples in the survey area, the method for which depends on the information available on the target population and risk factors. The robustness of the conclusions of surveys designed using these approaches depends strongly on the survey preparation. The methodology here proposed allows surveys to be compared across time and space, thus contributing to harmonisation of the X. fastidiosa surveys in the EU Member States. The extremely flexible approaches allow surveys to be tailored to each specific situation in the Member States, taking into account the host plants, vectors, climate suitability and resources available. The success of a good survey design relies on technical aspects of the survey preparation and on the involvement of the risk managers

Scientific Opinion on the risk to plant health posed by <em>Phialophora cinerescens</em> (Wollenweber) van Beyma for the EU territory, with the identification and evaluation of risk reduction options

The Panel on Plant Health conducted a pest risk assessment for Phialophora cinerescens (Wollenweber) van Beyma (the causal agent of Phialophora carnation wilt) for the EU territory, identified risk management options and evaluated their effectiveness. The risk assessment was conducted taking into account current EU legislation. The Panel also provided an opinion on the effectiveness of the present EU requirements against this organism, listed in Council Directive 2000/29/EC. Four pathways for entry were identified. Plants for propagation (rooted and unrooted cuttings of host plants) were considered as a major pathway. Entry via this pathway was rated as unlikely because of the effective disease prevention techniques for cuttings now in place in places of production. P. cinerescens has been found in most Member States but with few occurrences or restricted distribution. In some Member States the pest was eradicated. Owing to current cultural practices and control measures, establishment in areas in which the pest was not previously present is considered very unlikely. For the same reasons, the probability of infection of crops is strongly reduced and hence the probability of spread to areas where the pest was not previously present is very unlikely. Similarly, the impact on carnation is at the moment minimal and unlikely to increase in the future. Risk reduction options to reduce the probability of entry and spread and mitigate the impact were evaluated; those addressing the phytosanitary status of the propagation material were considered to be the most effective and feasible (e.g., the officially accepted carnation certification system for source planting material), including the current regulations laid down in Council Directive 2000/29/EC. If the current regulation were removed, a certification system could be just as effective as the existing regulation, provided it included practically all the prescriptions of the present regulation