Statement of EFSA on host plants, entry and spread pathways and risk reduction options for Xylella fastidiosa Wells et al.

Abstract

Following a request from the European Commission, EFSA was asked to provide urgent scientific and technical assistance on the plant pathogenic bacterium Xylella fastidiosa. X. fastidiosa was detected in olive trees in Lecce province in Apulia, Italy, in October 2013. This is the first outbreak of X. fastidiosa under field conditions in the European Union. EFSA reviewed the host range and vectors, the pathways for entry and spread and the risk reduction options. Known hosts include many cultivated and spontaneous plants common in Europe, however a range of European wild plant species would meet this bacterium for the first time, increasing uncertainty on the host range. All xylem-fluid feeding insects in Europe should be regarded as potential vectors of X. fastidiosa and identification of the vector in the Apulian outbreak is pending. The main entry pathway for X. fastidiosa is the movement of plants for planting. Infective vectors of X. fastidiosa transported on plant consignments are also of concern. The only route for natural spread of X. fastidiosa is by insect vectors that generally fly short distances up to 100 metres, but can be transported by wind over long distance. The movement of infected plants for planting is the most efficient way for long-distance dispersal of X. fastidiosa. There is no record of successful eradication of X. fastidiosa once established outdoors due to the broad host range of the pathogen and of its vectors. Strategies for prevention of introduction from areas where the pathogen is present and for containment of outbreak should focus on the two main pathways and be based on integrated system approach combining, when applicable, the most effective options.

Experimental Nets for a Protection System against the Vectors of Xylella fastidiosa Wells et al.

“…Saponari et al [5] demonstrated that olive trees with leaf scorch symptoms (i.e., branches with basal and apical pale green leaves, later expressing different degrees of scorching starting at the leaf tips, partial defoliation, and death of shoots and branches) were positive for Xylella fastidiosa Wells et al subspecies pauca, sequence type (ST) 53 (Xanthomonadales, Xanthomonadaceae) [6]. This study was the first widespread detection of this bacterium in Europe, and a quarantine around the infected area was imposed [7]. Unfortunately, quarantine was not able to limit the diffusion of the bacterium and, by the end of 2013, the affected area had grown to almost the entire Salento Peninsula.…”

Antimicrobial Peptides With Antibiofilm Activity Against Xylella fastidiosa

“…It is also responsible for other plant diseases such as citrus variegated chlorosis ( Rapicavoli et al, 2018 ) and almond leaf scorch disease. In 2013, it was introduced in Italy and is spreading through the Mediterranean region causing a new disease named olive quick decline syndrome ( EFSA, 2013 ). The increasing dissemination of X. fastidiosa can be related to many factors, such as climate conditions optimal for its growth, its easy spread through insect vectors from the Cicadellidae (sharpshooter leafhoppers) or the Aphrophodridae (meadow spittlebug) families, and the huge number of hosts that it can infect ( Almeida and Nunney, 2015 ; EFSA, 2015 ; Strona et al, 2017 ).…”

Table_1.DOCX

“…It is also responsible for other plant diseases such as citrus variegated chlorosis (Rapicavoli et al, 2018) and almond leaf scorch disease. In 2013, it was introduced in Italy and is spreading through the Mediterranean region causing a new disease named olive quick decline syndrome (EFSA, 2013). The increasing dissemination of X. fastidiosa can be related to many factors, such as climate conditions optimal for its growth, its easy spread through insect vectors from the Cicadellidae (sharpshooter leafhoppers) or the Aphrophodridae (meadow spittlebug) families, and the huge number of hosts that it can infect (Almeida and Nunney, 2015;Strona et al, 2017).…”