Scientific Opinion on a technical file submitted by the US Authorities to support a request to list a new option among the EU import requirements for wood of Agrilus planipennis host plants

Abstract

This document presents the scientific opinion of the Panel on Plant Health on the technical file submitted by the US Authorities to support a request to list a new option among the EU import requirements for wood of Agrilus planipennis host plants. The option under consideration is a heat treatment at 60 °C for 60 min to eliminate possible infestations of the wood by the emerald ash borer (EAB). The experiments leading the US Authorities to propose this option are presented in a scientific peer reviewed publication, . The analysis of the aggregated data published by and based on a Probit regression model showed that the proposed treatment cannot guarantee a control level of 99 % or higher. The analysis of the individual data either from the original measurements or from a corrected dataset, using a Probit regression model, showed that it is likely to observe one live EAB out of an infestation of 100 after the proposed heat treatment of 60 °C/60 min. To ensure a control level of 99 % the temperature of the heat treatment of 60 min should be higher than 70 °C. Results obtained with a Poisson log linear model based on individual data showed that the estimated probability that one insect or more per m 2 survive the proposed heat treatment was higher than 0.6 and that there is a 0.1 probability that three insects or more per m 2 survive the proposed heat treatment. Based on these results, the Panel concludes that A. planipennis is likely to survive the proposed heat treatment of 60 °C/60 min with a low uncertainty, and that the alternative option proposed in the technical file submitted by the US Authorities for wood does not guarantee the wood to be free of A. planipennis. During the critical review of the different datasets provided by the US Authorities, the Panel found important inconsistencies. Therefore, in order to reduce uncertainties on the results of the analyses, four datasets were considered to explore the dependence of the model outcome on the possible input datasets.The analysis of the aggregated data used by Myers et al. (2009) based on a Probit regression model showed that the proposed heat treatment of 60 °C/60 min cannot guarantee a control level of 99 % or higher. The analysis of the individual data using a Probit regression model showed that it is likely to observe one surviving emerald ash borer out of an infestation of 100 after the proposed heat treatment of 60 °C/60 min. To ensure a control level of 99 % the temperature of the heat treatment of 60 min should be higher than 70 °C. Results obtained with the Poisson log linear model showed that the estimated probability that one insect or more per m 2 survive the proposed heat treatment was higher than 0.6 and that there is a 0.1 probability that three insects or more per m 2 survive the proposed heat treatment.The rate of survival of EAB prepupae after heat treatment documented in the additional published studies that were examined, suggests that individuals may survive after exposure to 55 ºC for 120 min, to 56 ºC for 60 min and to 60 ...

Commodity risk assessment of ash logs from the US treated with sulfuryl fluoride to prevent the entry of the emerald ash borer Agrilus planipennis

“…Larval development occurs in four instars during summer and autumn. Most of the larvae (> 80%) stop feeding in October-November; the overwintering stage is the mature fourth instar larva in a prepupal cell in the outer bark or sapwood about 1 cm deep (4-16 mm) (Cappaert et al, 2005;EFSA PLH Panel, 2011). Pupation and adult emergence occur from mid-April to summer (Cappaert et al, 2005).…”

“…This is most readily observed in trees with low larval densities, or when oviposition occurs in late summer; however, other factors, such as low temperatures, host defence reactions or low nutrient levels may also be involved (Cappaert et al, 2005). In China, the 2-year cycle has been found in areas where temperatures below 0°C last for more than 150 days per year (EFSA PLH Panel, 2011, citing Wei et al, 2007.…”

Pest survey card on Agrilus planipennis

“…Agrilus planipennis is a metallic green beetle with typically elongated body, 7.5-13.5 mm long ( Figures 15B, E and 16H) (Parsons, 2008;EFSA PLH Panel, 2011). Beetles have a very distinctive coppery red coloration of the abdomen visible underneath the elytra (Figure 1).…”

“…Their combined native range covers the entire territory of the EU (Figure 6). Fraxinus excelsior is the most widespread species and can be found in natural mixed and planted broadleaved forests and as a common urban tree across Europe and is widely used as a hedgerow tree in Great Britain (EFSA PLH Panel, 2011;EPPO, 2013a;Beck et al, 2016). Fraxinus excelsior is a very large component of floodplain forests in northern…”

“…Several non-native Fraxinus species are cultivated in the EU as ornamental trees in cities and parks (especially in Eastern Europe), including North American F. americana, F. latifolia, F. pennsylvanica, F. nigra, F. velutina, and Asian species F. mandshurica (EFSA PLH Panel, 2011;EPPO, 2013a;CABI, 2019b). Fraxinus pennsylvanica in particular is commonly found in north-eastern European cities and widely planted in floodplains as a shelter belt and timber tree (Schmiedel et al, 2013).…”