The Mighty Termite: Scientists work to corral the spread

The LSU AgCenter is participating in an areawide integrated pest management effort called the French Quarter Program in New Orleans as a part of Operation Full Stop, a nationwide termite management program. (Photo by Johnny Morgan)

The French Quarter Program included the blocks in pink at the beginning but has expanded to the green and blue areas. (Illustration by Barb Corns)

The French Quarter Program involves trapping flying termites, known as alates, during the swarming season in the spring.

LSU AgCenter scientists continue to add weapons to their arsenal as they battle the spread of the Formosan subterranean termite. And they’re making headway. This pest voraciously consumes wooden structures and trees and causes hundreds of millions of dollars in damages.

Believed to have entered Louisiana and other Southern coastal states in wooden crates returned from the Pacific Rim during and after World War II, Formosan subterranean termites have steadily increased in number over the past 60 years. They have moved north from New Orleans and Lake Charles and now have been found in all parishes south of I-10 and I-12 as well as in some areas of north Louisiana.

The LSU AgCenter has developed several programs in research and education to help Louisiana battle this odious pest. A pop-up termite indicator, the ink from a ballpoint pen and a grassy plant used worldwide for erosion control may provide new, environmentally safe weapons in the arsenal to combat subterranean termites. And long-term research in the New Orleans French Quarter is providing information on the effectiveness of treatment programs.

Pop-Up Indicator

Gregg Henderson and Jay Paxson of the Department of Entomology have developed a pop-up device that can indicate the presence of subterranean termites. The AgCenter has a patent on the indicator, which presents a clear visual signal when termites consume a food “trigger” that trips a signal to show they have been active.

The simple, inexpensive signal device can be adapted to fit almost all commercially available monitors or bait stations. The invention takes advantage of one of the newer, safer methods of controlling termites by placing toxins in bait stations that are placed around a structure – either above or below ground. These bait stations intercept termites by luring them with foods and causing them to carry toxin-laced baits back to their nests where they feed other members of the colony.

The device can signal the presence of termites without disturbing a buried monitor or bait station, and because the signal is outside the housing, the monitor doesn’t have to be transparent or visible. The pop-up indicator has been licensed by Orkin for use in professional applications.

Non-repellent Toxins

Henderson also has been researching toxicants that are nonrepellents – termites don’t know they’re in a toxic zone. To help the termites find the toxin, Henderson is using the chemical from ballpoint pen ink. Termites naturally follow their own chemical trails to find their way between their nest and a food source. Henderson has learned that a chemical in ballpoint pen ink is similar to the chemical termites use to lay their trails, so he’s using that knowledge to lure the insects to a toxic area. The termites pick up the toxin on their bodies and carry it back to the nest, where it’s passed on to other termites that ingest it through grooming.

With most chemicals, termites become sluggish and don’t travel far after eating baits. With one particular contact material, however, the termites act normally and don’t slow down. “It’s like baits, but the transfer is through touching, not feeding,” Henderson said. Contact toxicants can be more effective than baits termites eat and feed to others because termites spend more time grooming each other than feeding each other. The drawback is that the termites doing the grooming eat the poison, so they don’t pass it on to others through grooming.

Nootkatone and Vetiver Grass

Henderson learned of vetiver grass’s potential as a termiticide from Don Heumann, a nursery and greenhouse operator in Metairie. Because he was aware of the growing damage termites are causing in the New Orleans area, Heumann thought he might be on to something when he noticed a lack of bugs in greenhouses where he was growing vetiver. So he took some plants to Henderson.

After experiments showed termites avoided going through sand mixed with ground vetiver roots, Henderson worked with Roger Laine of the LSU Department of Biochemistry to extract oils from the roots. The scientists discovered the oils contain a chemical called nootkatone, which it turned out is both a repellent and toxic to termites. They conducted further studies that indicated nootkatone affects other insects as well.

Henderson is evaluating nootkatone to determine if vetiver grass roots used as mulch are effective in controlling Formosan subterranean termites. He said the study shows that a 25 percent vetiver root mulch treatment proved to decrease tunneling activity and wood consumption and to increase termite mortality.

“Nootkatone added to the mulch can control termites and fire ants with no effect on citrus trees,” Henderson said. “This can reduce cost and increase efficacy for termite control.”

French Quarter Program

The LSU AgCenter is participating in an areawide integrated pest management effort called the French Quarter Program in New Orleans as a part of Operation Full Stop, a nationwide termite management program. Its focus is a community-based plan using a management strategy to reduce the densities of Formosan subterranean termites. The program is a cooperative effort including the U.S. Department of Agriculture and the New Orleans Mosquito and Termite Control Board.

The federally funded program pays the pest control applicators, so building owners have no out-of-pocket expense for the treatments. Although hurricanes Katrina and Rita interrupted the project, the French Quarter had little flooding, and the research continues.

The program began in 1998 in a limited area and has been expanded into additional parts of the French Quarter since then. Two types of treatments are being used to try to decrease the Formosan subterranean termite numbers in the French Quarter test area, according to AgCenter entomologist Dennis Ring.

“We have baits that the pest management professionals monitor on a monthly basis and liquid treatments that are inspected yearly,” Ring said. “The treatments are applied by local pest management professionals using commercially available baits or nonrepellent termiticides.”

The best evidence of success in the French Quarter project comes from the inspection of buildings in the original 15 blocks included in the test area, according to Frank Guillot, USDA’s national program coordinator for the Formosan termite program. Inspections of properties in 2003 found 26 percent of the buildings were infested with live termites. Inspection results for 2005 showed 5 percent of the buildings are infested.

Formosan subterranean termites expand their territories naturally by producing winged “alates” that swarm each spring. One measure of effectiveness of the program is done by trapping alates during the swarming season in late spring and early summer.

Alate numbers are sampled using sticky traps placed on light poles in the French Quarter. Along with monitoring alates, in-ground monitoring stations have been installed in holes drilled through the sidewalks throughout the French Quarter.

(This AgCenter Lead was updated on May 20, 2008, by Linda Benedict.)