Xylella Fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy

A team of researchers from the European Commission – Joint Research Centre (Ispra, Italy) and from the School of Mathematical and Geospatial Sciences, RMIT University (Melbourne, Australia) just released the paper entitled “Network analysis reveals why Xylella fastidiosa will persist in Europe”, published on the current issue of “Scientific Reports” and available at the following link: http://go.nature.com/2m9M7it
The authors using a high resolution map of the olive orchards in Apulia (southern Italy), and under the assumption that Xylella fastidiosa can be transported by a vector between host plants that are up to 1 km apart, generated a network of potential X. fastidiosa infection pathways in Puglia by connecting all pairs of olive orchards (nodes of the network) that are within the vector’s reach.

The outcomes of this network’s structure show that, regardless of epidemiological uncertainties, the mere distribution and the topology of the olive orchards in Puglia favors persistence of the Xylella fastidiosa epidemic, and complicates management prioritization.
Thus, efforts to reduce the prevalence of Xylella fastidiosa in the region, primarily through vector control and reduction of inoculum sources, are fundamental to lower the risk that the infection spreads to olive crops in other Italian areas and Mediterranean countries.



Abstract: The insect vector borne bacterium Xylella fastidiosa was first detected in olive trees in Southern Italy in 2013, and identified as the main culprit behind the ‘olive quick decline syndrome’. Since then, the disease has spread rapidly through Italy’s main olive oil producing region. The epidemiology of the outbreak is largely unstudied, with the list of X. fastidiosa hosts and vectors in Europe likely incomplete, and the role humans play in dispersal unknown.

These knowledge gaps have led to management strategies based on general assumptions that require, among others, local vector control and, in certain areas, the destruction of infected plants and healthy ones around them in an attempt to eradicate or halt the spreading pest. Here we show that, regardless of epidemiological uncertainties, the mere distribution of olive orchards in Southern Italy makes the chances of eradicating X. fastidiosa from the region extremely slim.

Our results imply that Southern Italy is becoming a reservoir for X. fastidiosa. As a consequence, management strategies should keep the prevalence of X. fastidiosa in the region as low as possible, primarily through vector control, lest the pathogen, that has also been detected in southern France and the island of Mallorca (Spain), continues spreading through Italy and Europe.