“It is devastating,” said Enzo Manni, director of ACLI-Racale, an olive cooperative in the heart of the outbreak area. “It is apocalyptic. I compare it to an earthquake.”
Today, scientists estimate that 1 million olive trees in the peninsula, known as the Salento, are infected with the bacterium, Xylella fastidiosa, a figure that could rise rapidly. The bacterium steadily restricts water flow from the roots of a tree to its branches and leaves.
More details at the StarTribune. The bacterium "is believed to have arrived with plants imported from Costa Rica and has destroyed citrus trees in Brazil and vineyards in California."