Abstract
Abstract
Citrus vein phloem degeneration (CVPD) is the Indonesian name for the Asian form of the devastating and incurable citrus disease known internationally as huánglóngbìng. It is associated with a phloem-limited pathogen, ‘Candidatus Liberibacter asiaticus’ (CLas) and transmitted by the Asiatic citrus psyllid (ACP), Diaphorina citri. ACP originated in South Asia but was first observed on citrus in 1900 in Java to where it may have been introduced decades earlier on lemon or lime seedlings brought from South Asia to reduce the incidence of scurvy among European sailors and in colonial settlements. CLas appears to have been introduced to the Pasar Minggu area of Jakarta in the 1940s from southern China, after it was introduced to Guangzhou, directly or indirectly, from South Asia in the late 1920s–early 1930s. Minimising incidence of the disease relies on planting pathogen-free trees, removal of infected trees, and unstainable use of synthetic pesticides that do not prevent spread of the disease. Parasitoids and predators of ACP are killed by the pesticides. Evidence from China and Việtnam suggests that effective management of the disease may be feasible if the weaver ant (semut rangrang), Oecophylla smaragdina, is deployed, cultivated, and managed in orchards.