Citrus trees and crops face serious threats from infectious diseases, especially citrus greening or huanglongbing (HLB). This disease reduces production and destroys the economic value of fruit. The spread and cause of HLB are associated with a phloem-feeding insect (Asian citrus psyllid (ACP), Diapharina citri) and a fastidious bacterium (Candidatus Liberibacter asiaticus). The Citrus Advanced Technology Program (CATP) was established to search internationally for solutions to HLB, citrus canker and other diseases through sponsored research.