Termites At The Statue Of Liberty

Chuck Woods (352) 392-1773 x 281

Nan-Yao Su (954) 475-8990
Al Farrugio (212) 363-6604
Mark Gilberg (318) 357-6421

NEW YORK — Give me your tired, your poor, your huddled masses yearning to breathe free. OK, but nobody said anything about termites.

For the past three years, termites in the Statue of Liberty National Monument have been a growing source of concern for the National Park Service. In fact, flying termites were so troublesome in April 1996 that Lady Liberty’s museum area was temporarily closed to visitors.

Now, with the help of a University of Florida scientist who has developed new environmentally friendly measures to stop the pest, termites have stopped swarming at the nation’s most famous national monument and will be completely under control by this summer.

“This is the first time in more than 100 years that there has been any problem with native subterranean termites on Liberty Island,” said Nan-Yao Su, professor of entomology and an internationally recognized termite expert with UF’s Institute of Food and Agricultural Sciences.

“I suspect termites found their way to the island when the statue was being restored for the 1986 Centennial celebration. They probably hitchhiked in with landscaping plants and wood construction materials.”

He said the most severe infestations have been in the pedestal or base of the monument that houses the museum and utility rooms.

“We had some serious termite infestations in the museum’s wooden display cases that contained valuable artifacts and historical documents, but none of these national treasures were damaged,” Su said. “At no time did the termites pose any threat to the structural integrity of the monument– they were not about to topple Lady Liberty.”

Al Farrugio, horticulturist at the statue, said the park service first noticed termites swarming in 1994 and asked Su to begin working on the problem. His work at the statue is supported by a grant from the park service’s National Center for Preservation Technology and Training, based in Natchitoches, La.

“The new control system eliminates the need for injecting pesticides into the soil that could leach into the harbor. It’s also well suited to sensitive historical sites like the Statue of Liberty,” Farrugio said.

Su said the key to success in controlling subterranean termites is getting the pesticide down into their underground colonies around the base of the monument. Unless the underground termite colony itself is destroyed, the pest will continue to build tunnels into the monument looking for wood.

“Termites are very picky about what they will eat and bring back to their underground colonies,” he explained. “They will literally seal off their nest from anything they don’t like.

“After testing many different chemicals, we found they will feed on hexaflumuron, a chemical which makes them unable to molt or reproduce. It eventually kills the entire underground colony,” he said.

Su developed a simple termite monitoring and baiting system that uses pesticide only when termite activity has been detected. Monitoring devices, placed in the ground around the statue, each contain pieces of wood. When termites begin feeding on the wood, it is removed and replaced with the hexaflumuron bait that slowly kills off the entire underground colony. Once the colony has been eliminated, the system remains in place to detect any future termite activity.

To control termites munching on the wooden display cases in the museum, he developed an above ground feeding station that delivers the bait on-site immediately.

“Around the monument, we’ve had our baiting system in the ground now for about eight months and we have not seen any flying termites in the statue this year. We got through April without any termite swarming, which is a good sign,” Su said. “We are keeping a close watch on the situation with the termite monitoring system and we won’t declare victory until Liberty Island is completely free of termites.”

Mark Gilberg, research coordinator of the park service’s preservation technology and training program, said Su’s termite control system also is being used to protect other historic landmarks, including the Cabildo and the Presbytere in New Orleans’ French Quarter.

“The technology is ideal for protecting historic properties because you don’t have to drill holes through floors, walls or any other fabric of the structure to introduce insecticides,” he said.

Gilberg said regular pesticide sprays didn’t stop the very destructive Formosan termite in the historic French Quarter buildings, but the control system has brought the pest under control for the first time by destroying its underground colonies.

The Formosan termite is a very aggressive species of the subterranean termite, and it is slowly spreading in the warm, humid climate of the southeast United States. Unlike the native subterranean termite, which has been found as far north as Toronto, the Formosan termite prefers warmer climates where colony populations average several million.

The termite control system is patented by UF and licensed exclusively to DowElanco of Indianapolis. It is marketed to consumers as the Sentricon Termite Colony Elimination System.



Posted: May 15, 1997

Category: UF/IFAS

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