Southern California citrus disease quarantine expands

A Southern California quarantine zone has been expanded in an effort to stop the spread of a disease that threatens the state's citrus industry. The Press-Enterprise reports the addition of 107 square miles encompasses the cities of Corona and Norco and part of Chino. It follows discovery of a dozen trees with citrus greening disease in Corona. The quarantine now covers 1,127 square miles in parts of Riverside, San Bernardino, Los Angeles and Orange counties. The quarantine forbids movement of fruit, citrus plants or foliage. Citrus greening is spread by a bug called the Asian citrus psyllid and eventually kills trees.