Linda Benedict, Bogren, Richard C. | 10/6/2009 8:43:06 PM
A historic 150-year-old cotton warehouse on New Orleans’ riverfront near the Garden District is the test site of a new patented bait system that holds promise of controlling the dreaded Formosan subterranean termite.
Gregg Henderson and Jian Chen of the LSU Agricultural Center developed the bait system that lures termites into a feeding chamber, then entices them into a second chamber that contains toxin-laced material the invaders carry back to their nest to kill the entire colony.
Henderson and Chen put out their first prototype bait stations Oct. 15, 1998. The apparatus is made from a plastic cylinder about 8 inches long and 4 inches in diameter. It is divided into two chambers by a wall with a small hole in the center.
The first chamber contains a small amount of cardboard as an introductory food source for the insect while a paper plug initially keeps termites out of the other section.
Because they do not know how easily a termite colony would find them on its own, the researchers placed termites in the non-toxic sections before they set them out.
Henderson’s crew put about 30 of the devices around the warehouse near mud-walled shelter tubes the targeted termites build and use for travel between their colony and food sources.
“Putting the apparatus near a shelter tube is easier than trying to find the actual colony site, which may be deep beneath the ground or, in the case of Formosan termites, hidden behind building walls,” Henderson said.
After these introduced termites feed on the cardboard, they should venture into nearby shelter tubes and lay down trails that termites in the targeted colony will follow back to the bait.
The trail that leads into the bait station is important. “Termites make and follow chemical trails to and from their nests to find their way back again,” Henderson said. “We hope we can take advantage of that to lure them to the toxicant.”
Eventually, the termites will consume the cardboard and then the plug between the two chambers of the bait system, opening up the second side containing the insecticide- laced bait.
“We use two chambers to make sure the termites blaze a trail to the colony and back again before they consume the toxicant,” Henderson said.
“The toxicant is a chitin inhibitor that affects the molting process of the termites, but it doesn’t harm people because we don’t have chitin, nor do we molt,” Henderson said. “The paper bait is being manufactured and provided by Ensystex, the newest bait on the market.”
Termite baits are slow-acting and may take about 6 months to effectively eliminate a problem, Henderson said. A cellulose-containing monitor can be used to measure consumption and termite activity and evaluate control.
Within six months from the start of the New Orleans study, Henderson expects to show significant control.
A termite colony can have a population from 500,000 to as many as10 million, he said. A quarter million termites can be killed with as little as 0.01 grams of active ingredient when it is provided in a bait formulation.