Tthe plants slowly suffocate, wither and dry up. They die en masse, the leaves drop and the bark turns gray, creating a sea of monochrome. Since scientists first discovered Xylella fastidiosa in 2013 in Puglia, Italy, killing a third of the region's 60 million olive trees – which once produced nearly half of Italy's olive oil – many of which were centuries old. Farms stopped producing, olive mills went bankrupt and tourists avoided the area. Without a known cure, the bacterium has already caused damage worth approximately 1 billion euros. (from Agostino Petroni and Regina Winter Poulsen in Puglia, more at theguardian.com)