What they look like:
Lethal Yellowing is a type of plant disease called a “phytoplasma”that attacks species of palm such as the coconut or date palm. This disease is spread by the Plant hopper, a tiny insect that feeds on trees and plants.
Behaviour:
Lethal yellowing is spread almost exclusively by the plant hopper insect. This insect feeds on the contents of a plants vascular system using piercing and sucking mouthparts, spreading the disease as it feeds and moves from plant to plant. After infection, the disease undergoes an incubation period of up to 8.5 months, before symptoms begin to occur. The first obvious symptom is the premature drop of fruits in mature plants, followed by the death of the plant’s flowers. The next symptom involves the yellowing and eventual death of the leaves. After the spear leaf (youngest leaf) dies, then no new leaves are formed, and the dead leaves begin dropping, leaving only the bare trunk. Infected palms usually take around 5 months after the appearance of the first symptom to die.
How they got there:
Lethal Yellowing disease was transported to the Caribbean via shipment of palms often used on lawns or gardens that also had plant hopper populations.
Predominant location/habitat:
Plant hoppers cannot survive in colder conditions, so lethal yellowing is usually seen only in tropical or subtropical palms in the Southern United States, Central and northern South America, and the Caribbean.
Effects on Biodiversity:
Lethal Yellowing has been shown to affect at least 36 different palm species, primarily palms that are not native to North America. Lethal Yellowing will eventually kill these plants.
Effects on people and the economy:
One of the most susceptible palms to the lethal yellowing is the coconut palm. This palm is use both as an ornamental plant but more importantly as a subsistence crop. Almost all parts of the coconut are used, providing food, drink, fuel, shelter, and most importantly income for those growing this crop. As a result, the loss of large areas of these palms have a significant effect on farmers who grow them as well as those who use the coconut by-products.
How to combat these invasive species:
There is no cure for lethal yellowing. However, plants can be treated to prolong their life by using the antibiotic ox tetracycline HCI (Tobramycin). Another option is to limit or exclude the use of palms from infected areas altogether. Also, one can use palm species that are not susceptible to lethal yellowing, such as royal palm and Christmas palm.