As if the sunshine state didn’t have enough problems already. Now even our beloved Florida palm tree is being threatened. An invasive disease spread by insects is responsible.
Florida Palm Tree Pest Disease
Known as lethal bronzing, it has gone from a small infestation on Florida’s Gulf Coast to a nearly statewide problem in just over a decade. Tens of thousands of palm trees have died, and the pace of its spread is increasing. Once a tree is infected, there is no chance for recovery.
Florida’s official state tree, the tall, broad-leafed sabal palm, is especially susceptible. Sadly, Florida nurseries, businesses, and homeowners are taking a financial hit as they scrap infected palms. There are some preventive measures. But once infected, uprooting the tree is the only practical solution.
“Getting this disease under control is essential because it has the potential to modify our landscape drastically,” said Brian Bahder, an entomologist. Bahder studies insect-borne plant diseases and is a leader in the state’s battle against lethal bronzing.
If we do nothing, Bahder said, “I don’t think all the palm trees will die, but the issue we see will get a lot worse before it gets better.”
Lethal bronzing, which experts say likely originated in Mexico, also is found in parts of Texas and throughout the Caribbean. Some worry it will migrate to California and Arizona, infecting date palms and damaging that fruit crop.
Florida Palm Tree Trouble
The disease has already heavily damaged Jamaica’s coconut plantations. Brazil is taking preventive measures to avoid invasion. But it seems the Florida Palm tree is the most recent victim.
Coincidentally, but conveniently, lethal bronzing is attacking palms right outside Bahder’s office at the University of Florida’s agriculture research station in Davie. Some are dying, and some are dead. This gives him a lab to test ideas and make presentations. As a result, he is not removing infected trees as recommended.
“To understand the disease, I need to watch it spread and see what it is doing,” said Bahder, an assistant professor with UF.
Lethal bronzing’s first Florida appearance came near Tampa in 2006. Sadly, it’s now found from the Keys in the south to Jacksonville in the north. The disease is transmitted solely by the haplaxius crudus. It’s a tiny winged insect sometimes called the American palm cixiid or, generically, a treehopper. These specific treehoppers (there are other kinds) inject the bacteria through their saliva when feasting on the sap from a palm’s leaves. Any palm cixiid that later feeds from the tree will pick up the infection and pass the bacteria to more palms.
Once inside a tree, the bacteria migrate to its base. Hence, multiplying until they clog the circulatory system. That is much like human arteries getting blocked by fat and cholesterol. The blockage makes it impossible for the tree’s cells to get sufficient nutrients and sugars. Thusly, starving them. As an infected tree dies, its fronds and central spear leaf transform from green to a tell-tale shade of bronze. Generally, the tree succumbs in about six months. The disease doesn’t infect humans or animals.