Huanglongbing (HLB) is the most destructive disease of citrus worldwide. The disease is caused by the proto-bacteria Candidatus Liberibacter asiaticus and transmitted by the Asian citrus psyllid Diaphorina citri. HLB symptoms are slow to appear, while the tree continues to be a source of inoculum. Monitoring tree health and rapid detection of HLB is critical for sustainable citrus production. Nowadays, scientists are working on developing new techniques for pre-symptomatic de