Xylella Fastidiosa Threatens Andalusia

A deadly, fast-spreading bacteria that poses a lethal threat to olive trees has been detected on the Spanish mainland for the first time -- putting half of the world's olive oil supply at risk.

Jul. 7, 2017
By Paul Conley

Recent News

A deadly bac­te­ria that destroyed olive trees in Italy last year has now been detected in almond orchards in Andalusia — the world’s largest olive oil pro­duc­ing region — pos­ing yet another chal­lenge to the indus­try.

Scientists con­firmed that the pathogen known as Xylella fas­tidiosa has infected almond trees in the Valencia region of Spain. At least so far, olive trees near the out­break site have remained unaf­fected. Officials destroyed some 300 olive trees as a pre­cau­tion and have sprayed the area for insects such as cicadas and spit­tle­bugs that are known to spread the dis­ease.
See Also:Complete Coverage of the Xylella Fastidiosa Outbreak

Xylella fas­tidiosa is deadly to olive trees, caus­ing a pro­found dry­ing effect that strips the plants of mois­ture and leaves trees look­ing as if they had been burned by fire. The strange and night­mar­ish result has led the dis­ease to be called olive tree lep­rosy” and the Ebola of olive trees.”

The bac­te­ria was first detected in Italian groves in 2013 and spread rapidly. Last year offi­cials there destroyed more than 1 mil­lion olive trees in an attempt to arrest the spread of the bac­te­ria.

Spanish offi­cials say they first spot­ted Xylella fas­tidiosa in their nation in cherry trees on the island of Mallorca. But in June, sci­en­tists found the pathogen on the main­land for the first time — in almond trees in the mas­sive olive-pro­duc­ing region of Valencia.


Spain pro­duces roughly half of the world’s sup­ply of olive oil. As recently as last April, exten­sive test­ing in Andalusia revealed no sign of the dis­ease and offi­cials declared the region Xylella-free.”

There is no known cure for the Xylella fas­tidiosa infec­tion.

The European Union has called Xylella fas­tidiosa one of the most dan­ger­ous plant pathogens on earth, with the abil­ity to destroy mul­ti­ple crops in rapid fash­ion.

Xylella fas­tidiosa is believed to have orig­i­nated in the Americas. One strain of the bac­te­ria has attacked almond and pecan trees in California and the south­ern U.S.

Fighting the dis­ease in Europe has proven dif­fi­cult. When author­i­ties destroyed trees in Italy in an attempt to halt the spread of the bac­te­ria, it prompted a back­lash from local activists. One local pros­e­cu­tor launched a crim­i­nal inves­ti­ga­tion into the sci­en­tists involved in the tree culling. Scientists’ com­put­ers and records were seized.

Shortly after that inves­ti­ga­tion began, the European Commission opened an infringe­ment pro­ce­dure — an inquiry into whether a mem­ber state had failed to adhere to European Union laws — alleg­ing that Italy had failed to carry out con­tain­ment mea­sures quickly enough.

Adding to fears among agri­cul­tural offi­cials is that, X. fas­tidiosa fas­tidiosa, a sub­set of Xylella fas­tidiosa native to Central America, was recently detected in Mallorca.

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