Bug vs. Bug: Scientists Use Microorganisms to Target Destructive Termites

Contact: Charmayne Marsh 202-872-4445 in Washington, D.C.

April 4--11, 2002, in Orlando, Fla.407-685-8070

EMBARGOED FOR RELEASE: Thursday, April 11, 1:45 p.m., Eastern Time

Bug vs. bug: scientists use microorganisms to target destructive termites

ORLANDO, Fla., April 11 -- Government scientists are developing a new weapon against the Formosan subterranean termite, a highly destructive species that has caused millions of dollars in damage to houses and trees in the United States. Their findings were described today at the 223rd national meeting of the American Chemical Society, the world's largest scientific society.

The method involves exposing the termites to their natural enemies, certain species of bacteria or fungi, which infect and kill the pests, said Maureen S. Wright, Ph.D., a research microbiologist with the U.S. Department of Agriculture's Agricultural Research Service, in New Orleans.

The development appears promising in laboratory tests and could provide an alternative or adjunct to pesticides, which might inadvertently harm the plants they are intended to protect, she said. In addition, it may benefit people who prefer not to use chemical pesticides in their home.

"Microorganisms represent an additional tool in the integrated pest management toolbox," said Wright.

According to the USDA, Formosan termite infestations have been found in 11 states: Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee and Texas.

Already, the Formosans have damaged large parts of the historic French Quarter in New Orleans, where they continue to wreak havoc on homes and many of the trees that line the city's streets.

Wright cautions that the new technology is not yet ready for marketing and continues to undergo refinement and further lab testing. Field-testing could begin as early as next spring, she said.

The Formosan termite is thought to have arrived in the continental U.S. nearly a half century ago. It is believed that the insects were first carried here as unwanted stowaways aboard wooden shipping crates carrying supplies home from the Pacific following World War II. Environmental factors here, including high humidity and moderate temperatures, allowed them to spread.

Environmental and health concerns have resulted in the removal of several chemical pesticides from the marketplace that were once effective in keeping the termites at bay.

In an effort to find an alternative, Wright and her associates turned to microorganisms, which are known to be natural pathogens of termites. The researchers screened hundreds of samples that are associated with the insects, including some that were collected from dead termites or found in the soil where they nest. Their ongoing search has produced three promising candidates so far: a bacterium (Bacillus) and two fungi (Metarhizium and Beauveria).

In laboratory tests, each candidate appeared to be highly lethal, with some strains killing 100 percent of a confined termite population within a one-week period, the researcher said. Similar methods using other microorganisms have taken up to four weeks to have the same effect and some never killed 100 percent, she said.

In addition to their potent killing power, the microorganisms offer a strategic advantage. They are self-propagating: Bacterial spores that attach to the bodies of the termites can be carried throughout their colonies, spreading to and killing the insects as the spores rejuvenate.

The researchers are currently trying to select these germs so that they poison the termites slowly. This approach gives the pathogens extra time to be distributed to more of the colonies' members by the termites themselves in an effort to destroy the entire colony, they said.

The microorganisms appear to work by literally eating away at the termites, most likely through an enzymatic degradation mechanism that breaks down their bodies, according to the researcher. Studies are ongoing to determine exactly how they work, Wright said.

If the tests prove effective, the germs could be turned into a powder or spray that could be directed at known termite infestations or possible hideouts. The microorganisms do not appear to be harmful to humans or plants, the researcher said.

This is not the first attempt to develop biological control agents for termites. Other labs are developing or refining similar techniques. However, Wright believes that her studies are producing more promising results to date.

"We still have a long way to go," she said, adding that the best weapon against these termites is probably an integrated approach involving a combination of biological control agents and chemicals.

The project is part of the USDA's Operation Full Stop, the government's multi-million dollar national program to control the Formosan subterranean termite. Known for its voracious appetite and massive colonies -- up to 10 million in a single colony -- this termite's territory continues to spread in spite of intervention efforts to stop it.

The USDA provided funding for this study.

-- Mark T. Sampson

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The paper on this research, I&EC 319, will be presented at 1:40 p.m., Thursday, April 11, at the Convention Center, Room 304F, Level Three, during the symposium "Agricultural Applications in Green Chemistry: Application of Green Chemistry Principles in Agriculture."

Maureen S. Wright, Ph.D., is a research microbiologist with the USDA's Agricultural Research Service, Southern Regional Research Center, Formosan Subterranean Termite Research Unit, in New Orleans, La.

Editor's note: A map depicting Formosan termite distribution in the United States can be found under the heading "Infestation Maps" at http://www.ars.usda.gov/is/fullstop/ Please note in relation to the map that there is no longer a known Formosan infestation in Tennessee, according to Alan Lax, Ph.D., research leader of the Formosan Subterranean Termite Research Unit, USDA-ARS Southern Regional Research Center, located in New Orleans, La.

#13200 Released 4/11/2002

Embargoed: Thursday, April 11, 1:45 p.m., Eastern TimeIEC 319 Non-technical SummaryDivision: Division of Industrial and Engineering ChemistryTitle: Biological control of the Formosan subterranean termitePresenting Author:Dr. Maureen S. Wright, Research MicrobiologistFormosan Subterranean Termite Research Unit, Southern Regional Research CenterAgricultural Research ServiceUnited States Department of Agriculture1100 Robert E. Lee Blvd.New Orleans LA 70124TEL:504 286 4294FAX:504 286 4419E-mail address: [email protected]

* Briefly explain in lay language what you have done, why it is significant and its implications, particularly to the general public.

Subterranean termites cause an estimated $1 billion in damage and prevention costs in the United States annually. The Formosan subterranean termite is responsible for a large, and growing, proportion of the cost. Chemicals which are non-repellant and slow-acting have been developed in an effort to control termite activity. This work reports the development of natural termite enemies, bacteria and fungi, as biological control agents that will complement the chemicals in an Integrated Pest Management scheme.

* How new is this work and how does it differ from that of others who may be doing similar research?

This work is part of an on-going research project. The data that will be reported were collected from 1999 to the present. The work is unique because it reports the comparison of termite biological control agents that were either investigated independently or were not previously investigated.

* Indicate if the material in your presentation (or similar research) has received prior media coverage and, if so, which publications or broadcast stations might have reported it.

This work is being conducted as part the the National Formosan Subterranean Research Program, Operation FullStop. This specific project has not been profiled in the media, but other aspects of Operation FullStop have been presented through outlets such as the Times-Picayune newspaper, and all TV and radio news channels in New Orleans; print and broadcast media in Hawaii and the Gulf Coast states of the US; CBS Evening News; Time Magazine; and BBC Radio.

Embargoed: Thursday, April 11, 1:45 p.m., Eastern TimeIEC 319 [504285]

Biological control of the Formosan subterranean termiteMaureen S. Wright, Formosan Subterranean Termite Research Unit, US Department of Agriculture, 1100 Robert E. Lee Blvd., New Orleans, LA 70124, Fax: 504-286-4419, [email protected], Phone: 504-286-4294

Subterranean termites cause an estimated $1 billion in damage annually to wood structures and trees in the United States. A predominant pest species is the Formosan subterranean termite, Coptotermes formosanus (Shiraki), which differs from native termite species in increased colony density and a propensity to destroy living wood. Control methods that have demonstrated effectiveness include novel termiticides and bait technology. In order for these approaches to work they must be non-repellant, transferrable, and have delayed toxicity to allow transfer from foraging workers to nestmates. An Integrated Pest Management (IPM) scheme will be necessary to reduce the impact of these pests. One component of IPM, and the focus of this work, is the development of biological control agents. Environmental conditions in termite infestation settings can vary greatly and some require unique treatment methods. Pathogenicity studies of microorganisms, including Bacillus, Metarhizium and Beauveria, show that biological control agents can enhance treatment flexibility.

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