Gregg Henderson | 9/8/2005 11:37:58 PM
That means termites in areas flooded by the aftermath of Hurricane Katrina may not be as prevalent as they have been for a while – offering a small grain of good news among the massive destruction.
"You can expect a population decline if the high water lasts several days to a week," said Dr. Gregg Henderson of the LSU AgCenter.
In fact, Henderson has studied how termites respond to floods, and the answers are rather surprising.
His study indicated that when they’re confronted with excessive amounts of water, subterranean termites escape drowning not by seeking higher ground but by entering an immobile state that conserves oxygen.
"In this suspended state, it took 30 hours of submergence for 90 percent of the eastern subterranean termites to drown, 23 hours for southern subterranean termites and 16 hours for Formosan subterranean termites," Henderson said in a report of his research. "That is a long time for any animal to hold its breath!"
The LSU AgCenter expert added that a natural soil profile or a log floating down a river would have air pockets, so the time before a whole colony drowned could likely take even longer.
"Such a natural event has been documented," Henderson said. "In 1992, an areawide flood in west central Georgia saturated the soil for more than a month and resulted in a 77 percent reduction in subterranean termite populations."
As a result, Henderson said he expects termite populations in the flooded areas of Orleans, Plaquemines and St. Bernard parishes may be reduced by up to 50 percent. Since Formosan subterranean termites also build nests above ground in wooden structures and trees, they may not be as affected as native termites.
"It will probably take at least a couple of years for those populations to recover," he said. "But they have a lot of good food for them – wet wood."
Henderson added that because of new products on the market, termite protection in new construction could be effective from the beginning.
"A study we conducted evaluated the likelihood of a colony getting its start in a normally dry wall," Henderson said. "Given the choice between a moist location and a dry location to start a new colony, the new queens and kings almost always chose the moist site."
That means new buildings, with termite barriers at the ground level and watertight construction throughout, should prevent future termite problems if the structures are properly cared for, he explained.
The LSU AgCenter and the LSU College of Agriculture