Last month I joined citrus farmers from California's central valley on a field trip to Southern California to see the Asian citrus psyllid firsthand. The Asian citrus psyllid (ACP) is an insect that spreads a disease that has the potential to kill every citrus tree in California and in every other citrus state; most of the trees in Florida are already infected and dying. The disease is called citrus greening or huanglongbing (HLB). Citrus greening is akin to Ebola for citrus trees, but it is more deadly (100% of infected trees die) and unlike Ebola, infected trees can spread the disease even when they do not show symptoms. Ebola is spread between humans via bodily fluids, but citrus greening is spread via Asian citrus psyllids. As Asian citrus psyllids spread throughout California, they will spread citrus greening whenever they feed on an uninfected tree after feeding on an infected tree. Citrus greening has already been discovered in Los Angeles in a citrus tree with an infected pummelo graft.
It is a good sign that since the first detection in Los Angeles, no more Asian citrus psyllids in California have tested positive for the bacteria that causes citrus greening; the reason may be that there has not been enough trapping and testing to find them, however. Scientists fear that there are more infected trees that have yet to be discovered. Just this month, Asian citrus psyllids were discovered in San Jose, Lodi, and Manteca in Northern California. These psyllid finds in Northern California were not anticipated and will dilute the resources of those fighting the psyllid and surveying for citrus greening. The neighborhood in San Jose where a breeding population of Asian citrus psyllids was found is considered high risk for greening-infected citrus trees.Continue Reading