Florida's $9 billion orange crop, the largest in the world after Brazil's, may not survive an incurable disease that threatens to wipe out citrus groves throughout the United States. The disease, known as "citrus greening" or huanglongbing, is caused by a bacterium, Candidatus Liberibacter asiaticus. The bacteria are spread from tree to tree by a tiny insect called the Asian citrus psyllid, The New York Times reports...