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Poster: Biology and Disease Management: Regulatory Plant Pathology


Regulatory implications of a newly discovered transmission mechanism for the pathogens that cause huanglongbing (citrus greening disease)
S. HALBERT (1), M. Keremane (2), C. Ramadugu (3), W. Dawson (4), J. Lee (5), J. Keesling (5), B. Singer (6), R. Lee (7) (1) Florida Department of Agriculture and Consumer Services, Division of Plant Industry, U.S.A.; (2) USDA/ARS, National Clonal Germplas

Huanglongbing (HLB, citrus greening disease) is one of the most devastating citrus diseases in the world. In Florida, it is associated with a bacterium Candidatus Liberibacter asiaticus (Las) and transmitted by a psyllid, Diaphorina citri Kuwayama. Lee et al. (2015; PNAS 112: 7605–7610) documented a new transmission mechanism for Las. An adult female psyllid, or her mate, infects the new growth where she lays eggs. The localized infection becomes a source for developing nymphs. Progeny can repeat the process as soon as they become adults. Since each female can lay 750 or more eggs, and psyllids can complete development in 15 days, the potential for increase of infected insects is rapid. In the laboratory, plants colonized by infected psyllids usually develop disease, but symptoms may be delayed for months or years. Catastrophic spread of Las can occur long before symptoms manifest. This delayed expression of disease symptoms could allow for the disease to spread undetected.