Green Oranges

The citrus apocalypse is coming. Last week David Karp in the New York Times described the fearsome situation facing Florida orange and grapefruit groves (registration required), which are threatened by a tiny insect called the Asian citrus psyllid: Once it infects trees, the fruits turn green and bitter (which is why the disease is called greening). And then the trees die. The insects were first spotted near Miami in 2005, but they are projected to infect all of Florida’s citrus trees within 7 to 12 years. A citrus grower quoted by Karp looks out at his dead trees and says, “Scientists have 10 years at the most to find a solution, or there’s not going to be a citrus industry in Florida.”

So that’s scary enough. But as if on cue, the story got worse: The Los Angeles Times a few days later reported that the citrus psyllid had hit California. Scientists had preliminarily identified the insect in a lemon tree in San Diego—it had been found in orange trees in Tijuana the month before—and were establishing a quarantine around the site. If it spreads, both states may be forced to insert genes for bacterial resistance into all of their citrus varieties. That’ll be controversial, but as a scientist told the New York Times, “it’ll probably come down to the point where people have to decide whether they want orange juice or not.”