In California, a warming climate will help a voracious pest—and hurt the state’s almonds, walnuts and pistachios
California almond farmers enjoyed record-breaking harvests over the last five years, after production dipped in the wake of 2014’s historic drought. That year a chorus of headlines vilified almonds for sucking up a gallon of water per nut, though irrigation efficiency has been improving. Now, as global temperatures rise, a caterpillar barely the size of a paper clip may threaten California’s position as the world’s leading producer of almonds, walnuts and pistachios.