Palm Lethal Yellows

Phytoplasma, formerly called mycoplasma.

Coconut palms (Cocos nucifera), fan palm (Pritchardia pacifica), and Canary Island date palm (Phoenix  canariensis) and many others.

Found throughout Florida, southern Texas,  Mexico, Caribbean and Central America.

The first symptom on coconut palms is premature dropping of most or all coconuts, regardless of size. Most of the fallen nuts will have a brown or black water-soaked area immediately under the calyx. The second stage, usually definitive for LY, is the blackening of new inflorescences. During the third symptom stage, from which the disease gets is name, fronds turn yellow, usually beginning with the oldest fronds and advancing upward through the crown. Fronds that have yellowed will die, turn brown and hang down. Death of the bud occurs about halfway through the yellowing sequence.  Finally the top of the tree falls away leaving a bare trunk or “telephone pole.” Infected trees usually die within 3-6 months after appearance of the first symptoms.

The Phytoplasma move thru sieve cells in the phloem causing their death. Progressive root loss results in chlorosis, stunting, decline and death. Leafhoppers carrying phytoplasma transmit the pathogen while feeding on host  trees. A plant hopper identified as Myndus crudus transmits the lethal yellows phytoplasma.