ADDRESSING THE THREAT OF HUANGLONGBING IN THE MEDITERRANEAN REGION: A CHALLENGE TO SAVE THE CITRUS INDUSTRY
N. Duran-Vila, J.D. Janse, X. Foissac, P. Melgarejo, J.M. Bové
Even though Citrus huanglongbing (HLB), caused by Candidatus Liberibacter spp., is not yet present in the Mediterranean basin, this devastating disease is threatening the very survival of citrus in most parts of the world. In the framework of an international course on “Emerging and Quarantine Diseases of Mediterranean Fruit and Vegetable Crops”, the participants were asked to hold group discussions to define measures for prevention and management of HLB in the Mediterranean Region. Following an introduction on the present situation of HLB in the world and emphasizing the facts that: (i) the African citrus psyllid, Trioza erytrae, is already present in the Canary and Madeira islands and threatens the western Mediterranean area and (ii) Asian HLB, with Candidatus Liberibacter asiaticus and the Asian citrus psyllid, Diaphorina citri, are present in Iran and the Arabian Peninsula and threaten the eastern Mediterranean area, a general discussion defined: (i) measures for prevention, including awareness, monitoring and surveillance, pest risk analysis, the establishment of quarantine measures, and practicing PCR detection methods for liberibacters in citrus and psyllids; (ii) action plans taking into consideration the presence of insect vectors and/or HLB-like symptoms; and (iii) future actions that must include the development of genetically modified citrus cultivars resistant to the causal liberibacter agents or to infection by the psyllid vectors. As management of HLB would be difficult in the Mediterranean area, in particular because of the small size of most citrus orchards, all efforts should be concentrated towards preventing HLB entrance and spread in the area.