Evidence of transmission of palm lethal yellowing agent by a planthopper, Myndus crudus (Homoptera, Cixiidae).
During studies carried out in Florida, lethal yellowing disease developed in 3 of 5 coconut palms, 5 of 7 Manila palms (Veitchia merrillii) and 2 of 3 examples of Pritchardia thurstonii that were planted in cages into which around 850 field-collected examples of Myndus crudus Van D. were introduced each month for 34 months. Transmission of the disease to 1 or more palms occurred in each of the 5 treatment cages. Mycoplasma-like organisms were observed in sieve elements in tissues sampled from all palms that developed lethal yellowing symptoms, but not in samples from healthy palms. Palms of the 3 species in 5 cages into which no planthoppers were introduced remained healthy. Insects that contaminated the experiment were discounted as possible vectors by biological and experimental design considerations. The number of examples of M. crudus used in the experiment and the susceptibilities of the palms were consistent with field observations. The results provide the strongest evidence yet published that M. crudus is a vector of the agent of palm lethal yellowing disease.