UF/IFAS Researchers Take Lethal Bronzing Research to the Masses

DAVIE, Fla. — The vast number of palm trees that enhance the landscape of homes, businesses, parks and highways throughout Florida are declining. The disease known as lethal bronzing is making its way steadily down the state and is creating casualties in South Florida’s palm tree population.

At center Brian Bahder talks with IHeart Radio talk show host Reno Grant about lethal bronzing and the upcoming workshop on September 25. Listen to WIOD 610 radio on Sunday, September 15, at noon for status of the disease affecting our state’s palm trees.

Work is underway at Fort Lauderdale Research and Education Center of University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and the first line of defense is prevention says Brian Bahder, assistant professor of vector entomology. Bahder is leading a team of researchers at the lab and who has witnessed the steady decline of the palm tree species throughout Florida.

“In 2016 you didn’t see this condition too often as far south as Palm Beach county,” adds Bahder who states the disease was first detected in Tampa, Florida in 2006. “Today it is prevalent in West Palm Beach. I can see the infected trees as I drive down the Florida Turnpike and I-95,” he adds.

Research has identified 16 species of palm trees that are vulnerable to the disease. Species like our state tree known as the sabal or cabbage palm, along with the silver date palms, and the queen palms are just three of the species found to be vulnerable to the bacteria known as phytoplasma. The bacteria spreads by an insect vector, that feeds on the tree.

While the insects are native to Florida and the Caribbean, only a small percentage of these insects, less than one percent of this vector population, are found to have the phytoplasma that infects the trees.

“What determines whether the vector can transmit the bacteria depends on the proteins in the stomach of the insect and whether the phytoplasma attaches itself to the stomach and then moves to the salivary glands,” said Bahder.

It all comes down to the molecular interactions of the vector. If it enters the salivary glands and it feeds on the palm tree, then it infects the tree, adds Bahder.

South Florida is home to a vast diversity of palm tree species.

What spreads the disease is when the insect then moves on to another and injects infected saliva in the healthy plant.

“The most important thing to note is that once symptoms show up on the palm tree, – it is too late, which is why prevention is the first line of defense,” said Bahder.

At this time, when a tree has been infected, the only remedy is to remove it. To prevent the bacteria from spreading, the surrounding trees require a sampling for the phytoplasma. If the palm is negatice then an antibiotic treatment of oxytetracycline is administered as prevention.

Dr. Bahder’s next stage is to develop management strategies for the disease along the roadways and in nurseries which are most susceptible to the disease. There is no doubt that the disease is infecting neighborhoods. Additionally, the team is working on research designed to lower the amount of plant hoppers in the environment.

On September 25, Dr. Bahder and his team will host the 3rd Annual Lethal Bronzing Disease Summit. The summit itinerary, designed for all levels of consumers from homeowners to landscape companies, will provide an overview of the research program, latest findings, treatment and management practices, and a tour of the Fort Lauderdale Research and Education Center in Davie to demonstrate the impact of lethal bronzing disease. Seating is limited to 50 participants. To register, please use the following link on Eventbrite.

In the meantime, the University of Florida conducts an ongoing collection of palm trees samples for owners who suspect the trees have been infected with legal bronzing disease.

There are some symptoms that the public needs to be aware of:

  • Bronzing of the lowest leaves meaning those that are closest to the ground,
  • Large layers of leaves starting to die off from the lowest part of the tree,
  • Fruit dropping prematurely.

Consumers who see signs of these symptoms and suspect they have lethal bronzing in their palm trees can submit a Palm Phytoplasma Sample Submission Form for a cost of $75. The sampling will be conducted by the Fort Lauderdale Research and Education Center.


By: Lourdes Rodriguez, 954-577-6363 office, 954-242-8439 mobile, rodriguezl@ufl.edu

The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human, and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resources industries and all Florida residents.

ifas.ufl.edu | @UF_IFAS


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Posted: September 13, 2019

Category: UF/IFAS

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