by Fintan Burke, Horizon: The EU Research & Innovation Magazine
A plant disease spread by sap-sucking insects has been devastating olive and fruit orchards across southern Europe, but scientists are inching closer to halting its spread with the help of insect repelling clays, vegetative barriers and genetic analysis.
In the late summer harvest of 2013, olive farmers in the Puglia region of southern Italy noticed that the leaves on several of their trees were turning brown and their shoots withering. The problem spread from one orchard to another, as more olive farmers found their trees were drying out and beginning to die.
Genetic testing confirmed them to be infected with Xyella fastidiosa, a bacteria originally found in America. Soon outbreaks appeared throughout the Mediterranean, even briefly as far north as Germany in 2016.
The bacteria is mainly spread by sap-sucking insects known as spittlebugs and sharpshooters. As the insects feed, the bacteria is able to infect the vessels that transport water and nutrients around the plant, known as the xylem. As the bacteria destroy the xylem, it slowly chokes the plant.