Xylella is here and it could be dangerous

Climate change and global trade combine to make it ever more likely that new pests and diseases will threaten food supplies. A classic example is playing out now in Puglia, the region that includes the heel of Italy's boot. The disease is caused by a bacterium -- Xylella fastidiosa -- that clogs the xylem vessels that carry water up from the roots. No water means leaves shrivel and scorch and eventually the host plant can die. In 2013, Xylella was found for the first time in Europe, in olive tre...