I recently visited the University of California, Davis in response to a reader's question about the rapid spread of huanglongbing disease (also know as citrus greening, HLB, or yellow dragon disease). Plant disease epidemiologist Dr. Neil McRoberts, a member of faculty at the plant pathology department at UC Davis, explains in the below video how the interaction between Asian citrus psyllids, liberibacter, and citrus trees causes this deadly citrus disease to spread so rapidly.
Please see below for resources related to huanglongbing and Asian citrus psyllids.