PDF(Pubmed)
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.
摘要：
EFSA植物健康小组对黄蜂进行了害虫分类，一种属于黄子科的革兰氏阴性细菌。病原体是一个定义明确的分类实体，它是梨叶烧焦的病原体。X.台湾存在于台湾岛的亚热带和温带地区，它影响了Pyruspyrifolia（亚洲梨）的低冷梨品种。据报道，没有其他植物物种受到病原体的影响。已知该病原体在欧盟境内不存在，也不包括在欧盟委员会实施条例（EU）2019/2072中。病原体进入欧盟领土的主要途径是用于种植的寄主植物（种子除外）；另一种可能的途径可能由推定的昆虫载体代表，尽管他们的身份仍然未知。在欧盟领土上，pyrifolia的种植面积非常有限。相反，与遗传相关的P.communis在大多数欧盟成员国中广泛种植，到目前为止，尚无有关其几种品种易感性的信息。如果害虫在欧盟建立，预计会产生经济影响，条件是存在合适的昆虫载体并且P.communis与P.pyrifolia一样易受感染。植物检疫措施可防止病原体引入和传播到欧盟，因为从台湾种植的植物是一条封闭的途径；尽管如此，推定向量，如果确认和识别，可能代表病原体的引入和传播的额外风险。缺乏关于X.Taiwanensis是否可以感染P.communis的知识，欧盟中合适载体的身份和存在导致进入时的关键不确定性，建立,传播和影响。X.Taiwanensis满足EFSA职权范围内的标准，以评估该物种被视为潜在的联盟检疫害虫。
