Pest categorisation of Xylella taiwanensis

Authors: BRAGARD, CLAUDE - Catholic University Of Leuven; BAPTISTA, PAULA - Instituto Politécnico De Bragança (IPB); CHATZIVASSILIOU, ELISAVET - Agricultural University Of Athens; DI SERIO, FRANCESCO - National Council Of Agricultural Research (CRA); GONTHIER, PAOLO - University Of Torino; JAQUES MIRET, JOSEPH ANTON - University Of Jaume; JUSTESEN, ANNEMARIE - Aarhuis University; MACLEOD, ALAN - Department For Environment Food And Rural Affairs (DEFRA); MAGNUSSON, CHRISTER SVEN - Norwegian University Of Life Sciences; MILONAS, PANAGIOTIS - Benaki Phytopathological Institute; NAVAS-CORTES, JUAN - Spanish National Research Council; PARNELL, STEPHEN - University Of Salford; POTTING, ROEL - Netherlands Food And Consumer Product Safety Authority; STEFANI, EMILIO - University Of Modena And Reggio Emilia (UNIMORE); THULKE, HANS-HERMANN - Helmholtz Centre For Environmental Research; VAN DER WERF, WOPKE - Wageningen University; CIVERA, ANTONIO VICENT - Instituto Valenciano De Investigaciones Agrarias; YUEN, JONATHAN - Swedish University Of Agricultural Sciences; ZAPPALA, LUCIA - University Of Catania; Chen, Jianchi; MIGHELI, QUIRICO - University Of Sassari; VLOUTOGLOU, IRENE - Benaki Phytopathological Institute; STREISSL, FRANZ - European Food Safety Authority; REIGNAULT, PHILIPPE LUCIEN - French Agency For Food, Environmental And Occupational Health & Safety (ANSES)

Submitted to: European Food Safety Authority (EFSA) Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2023
Publication Date: 1/20/2023
Citation: Bragard, C., Baptista, P., Chatzivassiliou, E., Di Serio, F., Gonthier, P., Jaques Miret, J., Justesen, A.F., MacLeod, A., Magnusson, C., Milonas, P., Navas-Cortes, J.A., Parnell, S., Potting, R., Stefani, E., Thulke, H., Van der Werf, W., Civera, A., Yuen, J., Zappala, L., Chen, J., Migheli, Q., Vloutoglou, I., Streissl, F., Reignault, P. 2023. Pest categorisation of Xylella taiwanensis. European Food Safety Authority (EFSA) Journal. 21(1). Article e07736. https://doi.org/10.2903/j.efsa.2023.7736.
DOI: https://doi.org/10.2903/j.efsa.2023.7736

Interpretive Summary: The European Food Safety Authority (EFSA) Plant Health Panel performed a pest categorisation of Xylella taiwanensis, a bacterial pathogen causing pear leaf scorch disease in Taiwan. Dr. J. Chen was invited to participate in panel discussion on the pathogen biology because the pathogen was described by Dr. Chen and colleagues in Taiwan. Currently, the pear pathogen is limited to Taiwan. Yet, the awareness of the pathogen is of importance to pear-growing regions around the world.

Technical Abstract: The EFSA Plant Health Panel performed a pest categorisation of Xylella taiwanensis, a Gram-negative bacterium belonging to the Xanthomonadaceae. The pathogen is a well-defined taxonomic entity, and it is the causal agent of the pear leaf scorch. X. taiwanensis is present in subtropical and temperate areas of the island of Taiwan, where it affects low chilling pear cultivars of the species Pyrus pyrifolia (Asian pear). No other plant species are reported to be affected by the pathogen. The pathogen is not known to be present in the EU territory and it is not included in the Commission Implementing Regulation (EU) 2019/2072. The main pathway for the entry of the pathogen into the EU territory is host plants for planting (except seeds); another possible pathway might be represented by putative insect vectors, though their identity remains unknown. The cultivated area of P. pyrifolia in the EU territory is very limited. Conversely, the genetically related P. communis is widely cultivated in most EU Member States and there is no information so far on the susceptibility of its several cultivars. Should the pest establish in the EU, economic impact is expected, provided that suitable insect vectors are present and P. communis is as susceptible to infection as P. pyrifolia. Phytosanitary measures are available to prevent the introduction and spread of the pathogen into the EU, since plants for planting from Taiwan is a closed pathway; nonetheless, putative vectors, if confirmed and identified, may represent an additional risk of the pathogen’s introduction and spread. The lack of knowledge on whether X. taiwanensis can infect P. communis, the identity and presence of suitable vectors in the EU lead to key uncertainties on entry, establishment, spread and impact. X. taiwanensis satisfies the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential union quarantine pest.