The city of Marco Island will spend $25,000 in emergency money to inoculate 616 trees along Collier Boulevard against the rugose spiraling white fly, a pest known for its messy excrement.
The bugs feed on palm trees, weakening them to other diseases. And while white flies aren't known to kill trees on their own, the excretion they leave behind, called honey dew, causes a sooty mold-like build up that is difficult to wash from lanais and sidewalks and can clog pool filters.
Tim Pinter, public works director with Marco Island, said the decision to inoculate Marco's trees came after a June presentation by local landscape entomologist, Doug Caldwell with the Collier County Extension Office of the University of Florida.
"We wanted to be proactive," Pinter said. "We went out and did an inventory and found we've just got a ton of white fly infestation on the island."
Inoculation involves an annual trunk injection. It will cost about $12,000 to treat the 616 Alexander and Cabbage Palm Trees along Collier Boulevard starting this week. The city will look at treating trees in city parks and then city rights of way with the remaining money, Pinter said.
"Hopefully we'll break the cycle," Pinter said. "If they can kill it off this first year, they may not come back next year."
Caldwell said the fly, which originated in Central America, is known to attack 80 types of plants. The insect was first spotted in Miami-Dade County in 2009 and spread to Collier County in October.
Caldwell said communities are facing judgement calls when it comes to paying for annual inoculation because the threat the fly poses to trees is not completely understood or as serious as the better known ficus white fly, which kills trees.
"With the coconut palm trees being a high priority plant and a tourist plant, it's got a high value," Caldwell said. "The coconuts took a beating two or three years ago with some storms and cold, so there's an accumulated stress going. Some areas are taking a wait-and-see approach about whether to treat them."
Caldwell said aesthetics play a bigger role in deciding whether to spend thousands in pesticides.
"It's a messy thing," he said of the sooty build up.
The city of Naples has decided not to inoculate its trees against the pest so far because of cost and because the fly hasn't posed a serious threat to city trees, said city arborist Joe Boscaglia.
"It hasn't risen to the level where we have to deem it an emergency," he said. "It's unsightly ... but it doesn't kill the host plant."
For now, Boscaglia's staff is spraying ornamental plants in some parts of the city as the need arises.
Collier County started treating some of its trees three weeks ago in Golden Gate Community Park and along some city rights of way. Arborists there are using both the inoculation method and a root drenching which allows the plant to soak up the treatment through the soil, said Connie Deane, community liaison for the county's growth management division.