Lethal Yellowing Palm Disease Spreading Quickly in Collier, Fla.

Lethal yellowing afflicts some 30 species of palm trees, but the most common victims locally have been coconut palms and Christmas palms.

Experts worry that if the disease gets out of control, it could wipe out what some consider to be the largest remaining stand of coconut palm trees left in Florida and the most striking contributor to Naples' brand of tropical ambience.

Both the city and the county have switched inoculation methods in hopes of fighting off the disease, but it remains to be seen whether the new method makes a difference.

In April, county commissioners revised their laws to streamline the county's response to new cases of lethal yellowing.

Later this summer, the Naples City Council might decide whether to require city residents to inoculate their trees against the disease.

Both steps are an indication that city and county officials are growing increasingly worried about lethal yellowing.

"It's a pretty devastating disease," said Joe Boscaglia, who manages the lethal yellowing inoculation contract for the city of Naples. "It's not something to take lightly."

The first reports of lethal yellowing in Collier County date to 1974. New outbreaks were reported in 1980, 1991 and 1998. Each time, a quick response was credited with limiting the damage. Since then, things have taken a turn for the worse.

Naples has borne the brunt of the disease, according to city and county figures.

City figures cite eight cases of lethal yellowing between 1998 and 2000. That number jumped to 27 in 2001, 36 in 2002, 103 in 2003 and 60 so far this year.

Outside the city limits, the county has counted fewer cases of the disease. County figures show 15 cases in 2001, 26 cases in 2002, 11 cases in 2003 and 12 cases in 2004.

"I wouldn't say it's a rampant thing where we're losing trees right and left," said Doug Caldwell, an agent with the Collier County Cooperative Extensive Service. "It's more a spotty thing, but it's spreading."

Marco Island, the Isles of Capri, Poinciana Village and the Henderson Creek area in East Naples have been hot spots for lethal yellowing, Caldwell said.

The county widened its assault on the disease after finding new cases on 104th Avenue and 94th Avenue in Naples Park, in the Grey Oaks neighborhood, in the Glades and in Everglades City.

Caldwell sees a bright spot among the hot spots: The disease seems to have stalled among Marco Island's huge coconut palm population — for now.

"If it gets going there it's going to be an ugly scene," he said.

After a tree is identified as having lethal yellowing disease, it is removed. An inoculation zone is set up for 100 yards around the tree. Coconut palms and Christmas palms within the zone get a dose of antibiotics every four months for at least two years.

Taxpayers are footing the bill for the inoculations, including for the trees that are on private property. After only one round of inoculations, the tab is approaching $30,000.

The county is inoculating some 580 trees with one-third to one-half of them in Grey Oaks, Caldwell said.

The city is inoculating 5,300 trees in nine protection zones that include the southern end of Kingfish and Tarpon roads in Royal Harbor, a section of Galleon Drive along Naples Bay in Port Royal, and along Marina Drive at the end of 21st Avenue South in Aqualane Shores.

Other zones include Pelican and Osprey avenues; a chunk of Old Naples that extends for three blocks north and south of Eighth Avenue South; the western ends of Fourth Avenue South and western ends of Second, Third and Fourth Avenues North.

Two other zones extend along a stretch of Gulf Shore Boulevard North, north of Harbor Drive, and cover most of Park Shore between Park Shore Drive and Rivera Drive.

"We're constantly out there, aggressively pursuing this, to try to suppress the disease," he said.

Nobody knows for sure what has caused the big jump in the number of lethal yellowing cases in the city.

New cases in Grey Oaks and at St. Ann on Eighth Avenue South have been traced to infected palms transplanted from infected nurseries on the East Coast.

At first, city crews were treating only infected coconut palms, leaving Christmas palms untreated within inoculation zones, said city construction project manager Terry Fedelem, who oversaw the city's fight against lethal yellowing until he took his new job.

"We didn't have quite the blanket on it we needed," he said.

Fedelem said another factor could have been the change from having city workers doing the city's tree trimming instead of private contractors.

City workers were trained to spot lethal yellowing and to report it so the city could jump on the problem quickly, Fedelem said. Early detection is a key to treatment, he said.

The disease is spread by tiny insects called planthoppers. The disease can kill a palm tree within three to six months of showing the first symptoms.

The disease doesn't attack cabbage palms, royal palms or queen palms. Symptoms can vary among susceptible palm tree species, and other problems with palms can look like lethal yellowing.

In early stages of the disease in coconut palms, all of its fruit drops off and has a blackened oily area where it was attached to the stem. After that, the tips of new flower stalks turn black, and the palm fronds turn yellow.

As the disease picked up momentum, city and county officials switched inoculation methods this year.

Both methods require the inoculator to drill a hole into the tree's trunk, insert antibiotic fluid and plug the hole.

The old method used a high-pressure injection system and a different formulation of the antibiotic used to fight off the disease.

The new method uses a low-pressure system that allows the tree to take up the antibiotic fluid more slowly.

Proponents of both systems say the other method doesn't deliver enough antibiotic to the tree.

The spread of the disease prompted the city to go with what it considers a more proven technology, Boscaglia said.

"We thought it was in our best interest to go ahead and try it and see what results we get from it," he said.

Fedelem said he considers the two methods to be of equal value until he can see the results from the new method.

He compared the city's fight against lethal yellowing with having a cat by the tail.

There's only so much scratching and clawing a person can take.

"There's probably a point at which we're going to have to say, 'Uncle, you've beaten us,'" Fedelem said.