A First: UF Researchers Help Eradicate Exotic Termite

May 19, 2004

FORT LAUDERDALE, Fla. — University of Florida experts and state officials have eradicated a newly introduced termite species from America’s shores, and they say this is the first time such an invasion has likely ever been stopped.

UF researchers say the tree termite, a tropical wood-devouring insect first discovered in Florida three years ago, could have caused as much as a billion dollars in property damage if it became established here.

“Because it damages homes, this pest ranks right up there with citrus canker in terms of the economic damage it could do,” said Rudolf Scheffrahn, an entomologist at UF’s Institute of Food and Agricultural Sciences. “We believe we’ve eliminated most if not all of the colonies of tree termites in South Florida, stopping the termite from getting a foothold here.”

Scheffrahn was the first entomologist called in when a pest-control operator spotted an unusual insect in a house in Dania Beach in the spring of 2001. The bugs had built a network of tunnels on the exterior walls of the house and were gnawing away at the wood from the outside, leaving unsightly scars on the building.

Scheffrahn, based at UF’s Fort Lauderdale Research and Education Center, identified the bug as Nasutitermes costalis, a pest commonly found throughout the Caribbean and South America. Unlike most termite species in the United States, which spend much of their lives underground, the exotic termites build nests above ground, usually in trees, and travel above ground in search of wood to devour. That posed a problem for local pest-control operators hoping to stop the insect.

“Most termite-control methods were developed for subterranean termites,” Scheffrahn said. “You put a pest-control agent into the ground around the house, and the termites pass through or feed on that agent and carry it with them. Tree termites travel above ground, like ants, so those methods won’t work.”

While homeowners in the termite’s native range have been fighting the bug for decades, their experience offered little help, said Brian Cabrera, a UF entomologist who worked on the tree termite-control project.

“This termite is found in many areas of the developing world, where people can’t afford pest control services or don’t have them available, so they’ll treat it themselves with whatever they have on hand,” Cabrera said.

In late 2002, the Florida Department of Agriculture and Consumer Services created an emergency task force dedicated to limiting the spread of the new termite. The task force included Scheffrahn and Cabrera, as well as state officials and pest-control operators.

“We weren’t sure we’d be able to wipe it out completely,” said Scheffrahn. “Most termites are hard to spot, and a new population is usually well-established by the time it’s discovered in an area. The tree termite is different, however, because the nests, tubes and damage are usually obvious. No one had ever completely eliminated an exotic termite before.”

When Scheffrahn and other UF researchers surveyed the area, they estimated the tree termite had been in Dania Beach for at least eight years before the insect was discovered. The infestation appeared to be centered in a junkyard, where the termites had built colonies in some abandoned tractor-trailers before spreading into the surrounding area. The bugs had even spread to a pair of boats in a marina not far from the junkyard.

Even so, the UF researchers found the infestation was limited to an area of one square kilometer – about a third of a square mile – a relatively small area for a newly discovered infestation. The finding raised the possibility that the task force might be able to eliminate the entire infestation.

With a $30,000 grant from the state, the UF researchers found that a pair of widely used pesticides could kill the bugs when sprayed on nests or infested trees. After three treatments with the pesticides, a survey of the area in early 2004 revealed only three remaining nests, which have since been treated. The UF researchers say further surveys and possible sprayings are planned in case some of the bugs remain. But the researchers say the tree termite has effectively been defeated.

“When we started this program, virtually every piece of wood in the ground in the infested area had termites in it,” said Scheffrahn. “The change is remarkable. It’s a different place after the treatments.”

Task force members say the program saved the state from a potentially costly pest, at little cost to state government.

“Our estimates show that if this termite had become established, it could have easily cost Florida residents a billion dollars through damage to buildings and added pest-control costs,” said Steve Dwinell, an assistant director of the Division of Agricultural Environmental Services for the state’s agriculture department and the organizer of the termite task force.

“If you’re looking for a cost-effective program, it would be hard to find anything better than that,” Dwinell said.