Dangerous outbreaks of the plant bac­te­rium ''XY­LE­LLA FAS­TI­DI­OASA''

Xylella fastidiosa was identified for the first time in the European Union in the Apulia region of Southern Italy, where it affected 8,000 hectares of olive trees. It has been proven that certain species of sucking insects act as vectors of the bacterium, which, by sucking sap, spread the infection to healthy plants. In addition to olive trees, the bacterium can also be detected in other plants, including almond, peach, plum, apricot, vines, citrus fruits, sunflower, coffee, as well as oak, elm, ginkgo biloba, etc. It is important to note that plants may carry the bacterium without showing symptoms of the disease. X. fastidiosa is a regulated quarantine pest in the European Union (EU), whose introduction and spread in the Member States is prohibited.

Due to the newly emerged outbreak in Italy, the European Commission requested EFSA to provide an opinion on the measures to prevent the spread of the bacterium, to establish the list of host plants, and to determine the different ways in which infected plant species and vector insects may enter the EU.

Experts from the EFSA Panel on Plant Health concluded that X. fastidiosa has a very wide range of host plants in the EU, as well as native wild species distributed in Europe. In addition, there is a large number of other species that could potentially be infected by the bacterium but have never been exposed to infection, which makes it even more difficult to determine the likely impact. Since the only mode of spread of X. fastidiosa is via vector sucking insects, which are known to be able to fly short distances of up to 100 metres, EFSA concludes that the movement of infected plants intended for planting is the most effective means of long-distance spread of X. Fastidiosa. In addition, the transport of vector insects together with plant consignments has also been identified as a possible risk for expanding the area of distribution. Therefore, the main source of spread of X. fastidiosa in the EU is trade and the subsequent movement of plants intended for planting. There are no data on successful eradication of X. Fastidiosa from an already infected plant. Therefore, EFSA recommends preventive methods and strategies for containment of the spread, whereby the focus should be directed to two main infection pathways – plants intended for planting and infected insects in plant production practices.