Guidelines for statistically sound and risk‐based surveys of Agrilus planipennis

At the request of the European Commission, EFSA has prepared these specific guidelines to guide the surveyor through the design of statistically sound and risk‐based surveys for Agrilus planipennis , integrating the key biological information. Based on examples, three different survey designs are simulated: (i) detection surveys to substantiate pest freedom, (ii) delimiting surveys to determine the boundaries of an infested zone, and (iii) buffer zone surveys to monitor a zone that ensures pest detection at low prevalence. The first step of the survey design consists of defining the objectives of the survey, characterising the host plant population and the methods used to detect the pest.The corresponding survey parameters are set while taking into account the importance of the underlying assumptions. The robustness of the survey conclusions will depend on the quality of the information used in this first step. The second step of the survey design consists of the sample size (i.e. number of traps) estimation using the survey parameters as inputs tothe proposed statistical tool (EFSA RiBESS+). The final step of the survey design is the allocation of the sample size in the survey area which depends on the available information about the target population and risk factors. The proposed methodology allows surveys to be compared across time and space, thus contributing to the harmonisation of A. planipennis surveillance across the EU. The flexible approach allows surveys to be tailored to the specific situation in a Member State, taking into account the ash tree distribution and available resources. Thesuccess of a good survey design relies on the survey preparation and on the involvement of the risk managers.