First reports of ‘Candidatus Liberibacter asiaticus’ in Guadeloupe and Martinique
Following the outbreaks of huanglongbing (associated with ‘Candidatus Liberibacter asiaticus’ – EPPO A1 List) in the USA and several Caribbean countries, a detection survey was carried out in both Martinique and Guadeloupe (FR) to verify the occurrence of the disease. Since 2012, 450 sites have been inspected every year. Leaf samples have been collected (20 leaves from 10 to 30 trees) and tested. As a result, ‘Ca. L. asiaticus’ was first detected in Guadeloupe in March 2012 at Le Moule on the Eastern coast in a Tahiti lime orchard (Citrus latifolia) and 6 months later, the pathogen was also found on the Western coast. In Martinique, ‘Ca. L. asiaticus’ was first identified in May 2013 on C. latifolia at Bellefontaine in a private garden and at Le Lorrain in an orchard. Other citrus species, C. reticulata and C. sinensis (mandarin and sweet orange) were also found to be infected by ‘Ca. L. asiaticus’ on both islands. However, few of the positive samples showed typical huanglongbing symptoms (most positive samples showed symptoms of nutrient deficiencies). On both islands, the insect vector is Diaphorina citri (Hemiptera: Liviidae – EPPO A1 List). In Guadeloupe, D. citri was first detected in 1998 but its populations have been controlled effectively with a parasidoid, Tamarixia radiata (Hymenoptera: Eulophidae). In Martinique, D. citri was first observed in 2012 (the EPPO Secretariat had previously no data on its occurrence). It is stressed that despite the former presence of T. radiata in Guadeloupe and its detection in Martinique a few weeks after the detection of D. citri, where it had a mean parasitism rate of 70%, huanglongbing has spread across both Guadeloupe and Martinique. The possible origin of these outbreaks remains unclear.
The situation of ‘Candidatus Liberibacter asiaticus’ in Guadeloupe and can be described as follows: Present, first found in 2012.
The situation of ‘Candidatus Liberibacter asiaticus’ in Martinique and can be described as follows: Present, first found in 2013.
Sources
Cellier G, Moreau A, Cassam N, Hostachy B, Ryckewaert P, Aurela L, Picard R, Lombion K, Rioualec AL (2014) First report of ‘Candidatus Liberibacter asiaticus’ associated with huanglongbing on Citrus latifolia in Martinique and Guadeloupe, French West Indies. Plant Disease 98(5), 683-684.