Application of Antibiotics for Control of Citrus Huanglongbing

Citrus Huanglongbing (HLB) is the most devastating disease of citrus. HLB has spread to most of the citrus growing areas in the world and causes significantly decline in both citrus production and citrus industry economic output. HLB is caused by three species of fastidious, phloem-resided alpha proteo bacteria: ‘Candidatus Liberibacter asiaticus’ (Las), ‘Candidatus Liberibacter americanus’(Lam), and ‘Candidatus Liberibacter africanus’ (Laf) [1-3], which are transmitted by the insect vectors, the African citrus psyllid, Triza erytreae [4] or Asian citrus psyllid Diaphorina citri [5]. Control of HLB in the field is urgently needed but difficult to achieve due to the lack of resistant citrus species and cultivars as well as effective integrated management. Chemotherapy is considered to be an effective short-term strategy for control of HLB. With the finding that prokaryotic organisms were associated with HLB, antibiotics have been applied by injecting into trees in several countries or regions in attempt to control citrus HLB [6]. Currently, many antibiotics have been screened and evaluated by our team and several were determined to be effective or partly-effective in combating HLB.