An historic 150-year-old cotton warehouse on New Orleans' riverfront near the Garden District is the site of a full-scale field test of a new patented bait system that holds the promise of controlling dreaded Formosan subterranean termites.
Dr. Gregg Henderson and Dr. Jian Chen of the Louisiana State University Agricultural Center developed the bait system that lures termites into a feeding chamber and then entices them into a second chamber that contains toxin-laced material, which the invaders carry back to their nest to kill the entire colony. Henderson and Chen put out their first full-scale tests with prototype bait stations Oct. 15.
Developed with funds from the LSU Ag Center, the apparatus is made from a plastic cylinder about 8 inches long and 4 inches in diameter. It's 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 insects and a paper plug that initially keeps termites out of the other section, Henderson explains.
Because they don't know how easily a termite colony would find them on its own, the researchers "pre-conditioned" the bait stations by placing termites in the non-toxic sections before they set them out.
Henderson's crew placed about 30 of the devices around the warehouse near the mud-walled shelter tubes that 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," the entomologist says.
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 says. "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 explains. The termites that eat the pesticide-laced paper will take the chemical back and feed others. Eventually, they'll all die as the toxicant is distributed throughout the colony.
"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 says. "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 six months to effectively eliminate a problem, Henderson says. 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 explains. 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. "We can't really prove the elimination of termites, only the lack of activity," Henderson says, "We may never be able to eliminate a colony, only knock it back and control it so it won't cause problems."
Contacts: Gregg Henderson at (225) 388-1831 or grhenderson@agctr.lsu.edu.
Rick
Bogren at (225) 388-2263 or rbogren@agctr.lsu.edu