This week, Puglia region president Nicola Vendola sent a letter to Italian Prime Minister Matteo Renzi requesting emergency relief for the growing Pierce’s Disease crisis that has already affected an estimated 2.5 million olive trees in Lecce province.
The effects of Pierce’s Disease, which is caused by the bacterium Xylella fastidiosa, have been widely documented in the U.S., where it was first discovered in the late nineteenth century.
Its presence in southern Italy was first reported two years ago. By some accounts, it has already destroyed a quarter of the olive groves in Lecce province.
According to PiercesDisease.org: “Pierce’s Disease is a deadly disease of grapevines. It is caused by the bacterium Xylella fastidiosa, which is spread by xylem feeding leafhoppers known as sharpshooters. Pierce’s Disease is known to be prevalent within the USA from Florida to California, and outside the USA in Central and South America. Xylella fastidiosa works by blocking the xylem [i.e., the wood], which conducts the water around the plant. Symptoms include chlorosis [yellowing] and scorching of leaves.”
For images of the damage caused by Xylella fastidiosa see this page on the Puglia Agriculture Superintendent website.
In the U.S., Xylella fastidiosa is known primarily for its effect on grapevines. In Puglia, the alarming outbreak has manifested itself primarily in olive groves.