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The Formosan Termite A Formidable Foe!
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Damage to a nest of Formosan
subterranean termites brings hoards
of workers and soldiers with dark,
oval shaped heads scrambling to
repair the hole. Termites shown
about 4 times actual size.
(K8210-10)
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Many are calling it the Second Battle of New Orleans, the
first having taken place in 1815, when General Andrew Jackson's troops defended
the city from the British. Today, the enemy isn't an army of redcoats, but an
exotic insect, Coptotermes formosanus--a.k.a. the Formosan subterranean
termite.
The city's so-called Second Battle is actually the first leg of a new
national campaign to rein in the tiny, ravenous pest. Originally from East
Asia, the Formosan termite infests over a dozen southern states, costing an
estimated $1 billion a year in property damages, repairs, and control measures.
In 1998, the U.S. Congress took action--appropriating $5 million to fund the
termite-fighting project, dubbed Operation Full Stop. It also appointed USDA's
Agricultural Research Service to lead the campaign, which is taking a decidedly
offensive approach to reducing large-area infestations of the pest.
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Formosan termite alates, also known
as swarmers, captured on a sticky trap
used to monitor populations.
(K8200-9) |
"Recognizing that the Formosan subterranean termite attacks any
number of targets from the same colony, defending a single building, a single
tree, a single location doesn't make a whole lot of sense, since they'll just
go around it and continue to increase their numbers. You've got to shift to a
large-area approach," says J. Patrick Jordan. He leads ARS' Southern
Regional Research Center (SRRC) in New Orleans, Louisiana, headquarters for
Operation Full Stop, which officially kicked off April 27, 1998, in the city's
French Quarter.
To help wage a full-scale assault on the pest,
Agricultural Research Service has formed
a coalition of public and private groups that includes the New Orleans Mosquito
and Termite Control Board, the Audubon Institute, USDA's Forest Service,
Louisiana State University's (LSU) Agricultural Center, Texas A&M
University, and the Universities of Florida and Hawaii.
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Microbiologist Alan Lax (left) and Patrick
Jordon, director of ARS' Southern Regional Research Center, examine sticky
traps covered with alates, the winged stage of the Formosan subterranean
termite.
(K8212-2) |
Rather than rely on chemicals as the sole defense, the project's
scientists are taking the offensive with an integrated pest management
approach. One avenue of attack will begin in the laboratory as researchers look
for ways to exploit weaknesses in the pest's biology, growth, chemical
communication, and behavior.
They'll also take the fight to the streets, so to speak, by setting out
commercial bait products around buildings and in parks. The baits work by
luring foraging termites to bite off food laced with an insect growth regulator
like hexaflumuron, which prevents the pest from molting.
Because the bait's ingredients don't kill right away, the termite has time
to carry the poisons back to the colony to share with its comrades.
In Gainesville, Florida, ARS scientists are building computer-generated,
geographic information system (GIS) maps. These will display numerous layers of
information, such as street and building locations, geological formations,
vegetation, and high-moisture areas. The maps will help authorities track
progress of various control strategies.
ARS researchers also plan travel to several East Asian countries in hopes of
identifying beneficial organisms that naturally attack the Formosan termite.
According to Jordan, nothing short of total war will curb the pest's numbers
and spread. "You've got to go after the whole nine yards, if you intend to
win," he says. "This is a major change in philosophy from previous
attempts to stop these termites."
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Some remnants of a nest are
visible in this cavity, which was
hollowed out by Formosan
subterranean termites while the
tree was still alive. Microbiologist
Alan Lax checks the extent of
the damage.
(K8213-10) |
Eyewitness Accounts
Those are welcome words to June Cahn, a businesswoman who lives in the
French Quarter--ground zero for Operation Full Stop. Like other residents,
Cahn's all too familiar with the pest's costly mischief. Recently, her son
James removed a beach-ball-sized nest from the walls of his home, a short walk
from the famed French Market.
"One of the things I've noticed about these termites is you don't
necessarily know what they're doing, where they're showing themselves,"
says Cahn. "And by the time you find out, your structure can be turned to
powder."
In addition to wooden structures, the pest devours live deciduous trees and
other woody plants. According to termite control board director Ed Bordes,
about 30 percent of the city's live oaks and cypress trees are now infested.
Even more frightening, this six-legged sneak is legendary for penetrating
cement, brick, plastic, and other obstacles to get to food or water sources. A
veteran of the Formosan termite war, Bordes has seen it all.
"We've seen trees fall on trucks; we've seen trees fall on
buildings--all infested with Formosan termites," says Bordes.
"They'll eat the seals out of high-pressure water lines to get to the
moisture inside."
Testing the Termite's Mettle
In May, Bordes joined a team of ARS and university scientists led by LSU
Agricultural Center entomologist Dcnnis Ring to start a large-scale pilot study
on a 15-block area of the French Quarter.
With the help of residents and building managers, the scientists are
evaluating use of two different baiting systems--one from Dow Agrosciences and
the other from FMC Corp. They're also testing Premise 75, a nonrepellent soil
termiticide from Bayer Corp.
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Formosan subterranean termites show no
respect for historic Jackson Square (foreground),
St. Louis Cathedral, or the neighboring Cabildo
at left, where the Louisiana Purchase transfer ceremony took place in 1803.
(K8085-8) |
The scientists are also installing monitoring stations. These devices
contain two thin pieces of wood within a plastic tube that can be inserted in
holes drilled into pavement or dug into the ground. Later, they retract the
wood to check termite activity.
Smaller, site-specific projects led by LSU Agricultural Center researchers
Gregg Henderson and Frank Guillot are under way at 15 schools plagued by the
termite in Orleans, Jefferson, and St. Bernard Parishes. Another is planned for
infested trees in Louis Armstrong Park. Bordes will oversee studies conducted
at the 30-acre park located just north of the French Quarter.
In these trials, scientists will evaluate and compare the performance of
individual control tactics in an isolated setting, such as treating wood with
borate and constructing physical barriers of fine-particle sand or
stainless-steel mesh. They'll also examine construction practices that could
minimize the ease with which termites gain access to a home via the soil.
An Unwelcome Stowaway
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Formosan subterranean termites
are feeding on Sudan-red-stained
filter paper. Tracking the termites
stained with this dye allows
researchers to estimate their
foraging range and population
numbers.
(K8204-7) |
Most experts believe the Formosan termite invaded the United States
half a century ago.
"The theory is that it infested crates, pallets, and other packing
material aboard ships carrying supplies and troops home from the Pacific
Theater at the close of World War II," says microbiologist Alan R. Lax. He
leads the SRRC's recently formed Formosan Subterranean Termite Research Unit.
Those supply ships offloaded their cargoes in the coastal cities of
Galveston and Houston, Texas; Lake Charles and New Orleans, Louisiana; and
Charleston, South Carolina. Inevitably, the used crates and pallets ended up in
landfills, often buried in soil--an ideal environment for these subterranean
termites, says Lax.
Still, it wasn't until the mid-1960s that scientists discovered the
unwelcome stowaway at these points of entry. Why the 20-year delay?
"The Formosan termite was unknown in the States before that time, and
populations were low," explains Lax. "The pest's winged stage also
resembles a commonly occurring drywood termite, which may have created some
confusion."
Eventually, it became obvious this was no native. Formosan termite colonies
dwarf those of native species, covering far more terrain and numbering many
times more members.
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Formosan subterranean termites
can turn solid beams into
shredded-wheat-likewood.
Entomoligist Ed Freytag (left) and
microbiologist Alan Lax inspect
damage to the floor of a building
in the French Quarter.
(K8212-18) |
Although it took time for it to establish itself and spread, the
Formosan termite has done so with startling success. Today, it infests Alabama,
Arizona, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, New
Mexico, North and South Carolina, Texas, and Virginia. Hawaii is a separate
story: That state's infestations date back far earlier.
For years, pest control operators fought a delaying action with chlordane,
an insecticide thought to remain potent in soils for up to 25 years--one trait
that proved the chemical's undoing.
In 1988, concerns over the chemical's risk to both the environment and human
health led to the loss of chlordane, exacerbating the Formosan termite problem.
Other compounds used since then have lacked the same staying power.
The termite, however, has plenty of staying power. In fact, it is now so
well established and widespread, experts say eradication is not a likely
scenario.
"One of our initial goals is to eliminate colonies and the damage they
cause within defined treatment areas," says Edgar G. King, associate
director for ARS' Mid South research area, headquartered at Stoneville,
Mississippi.
"We're evaluating the best technologies available now and assembling
them into a package the pest control industry can use," says King. Thus
armed, public or private pest control operators could then begin the task of
attacking termites that bedevil a particular city or state.
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Taking a Stand
A chief reason for Operation Full Stop's starting with New Orleans is that
the city has fallen prey to one of the largest and most destructive Formosan
termite infestations.
"We're estimating that we're losing about $300 million a year in the
metropolitan area to termite damage and control costs," says Bordes.
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The French Quarter in New Orleans harbors one
of the heaviest Formosan subterranean termite infestations in the country.
Here, a tamper-proof metal cap in the street marks the location of a
monitor/baiting station in an area that is already under treatment.
(K8208-6) |
A humid, near-tropical climate contributes to the problem. Another
factor is the architectural character of the city's French Quarter. Many of the
buildings there are historic landmarks with foundations supported by woodwork
dating back to the 1700s in some cases.
Consider, too, the row-style homes. Their shared walls give foraging
termites easy access from one building to the next. This hampers pest control
efforts to treat or fumigate a single client's home or building.
"Formosan termites have definitely changed the way pest control
operators do their business," says Edward Martin, who is with Terminix,
Inc., of New Orleans.
"They are extremely strong survivors," says Martin of the pest.
"So even if they are cut off from the ground--if you've trapped hundreds
of thousands of termites in the building--there's a good probability they will
find some minuscule moisture source and build a nest right in the
building."
Detection, he adds, is the key. "I think that since we've come in with
the bait systems--which seem to be working very well--we have the ability to
reduce these colonies. But if we can't find them, we can't bait them."
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A termite monitoring/baiting station
is being installed in a grassy area.
The station is manufactured by
Dow Agrosciences.
(K8198-17) |
That's something Operation Full Stop scientists aim to remedy. They are
establishing collaborative ties with National Aeronautics and Space
Administration and U.S. Department of Defense researchers to devise sensing
techniques to find termites hiding within walls and other hard-to-reach places.
The standard approach is to visually inspect a structure. With help from the
defense or space industry, tomorrow's tools of detection might instead rely on
electrical current, acoustic sound, infrared light waves, or some other as yet
untapped technology. Equipped with such early warning systems, "we could
apply an offensive strategy to eliminate the invading termites before they do
substantial damage," says Lax.
Changing the Enemy's Behavior
SRRC scientists are also working closely with LSU entomologist Henderson and
colleagues to decipher the pest's chemical communication. They hope to
synthesize chemical come-hither signals that the termites use to attract fellow
termites to food sources and other locations. These signaling chemicals could
be used to make toxic baits even more irresistible--and deadly. The university
group has also shown that aspartic acid, a natural chemical in sugarcane, whets
the Formosan termite's appetite.
"A large part of our research is to look for ways to modify termite
behavior," says Henderson. "Termites orient to chemicals. So we want
to find the chemicals they are using and then try to use them against the
pests, both as feeding stimulants and attractants."
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Wood blocks placed in this
monitoring/baiting station are
checked at regular intervals for
signs of termite activity. If any is
found, poisoned baits are placed
inside. Foraging workers consume
and spread the poison
throughout their colony.
(K8196-14) |
Similar work is under way at the University of Florida in Gainesville.
There, Operation Full Stop collaborator Nan-Yao Su is studying the termite's
behavior and colony dynamics. Like ants, termites are social insects with a
caste system that includes workers, soldiers, and alates, the winged forms that
become the kings and queens. Queens can lay 2,000 to 3,000 eggs a day.
Exploiting the Formosan termite's nutritional needs is one focus of the new
SRRC research unit.
"We anticipate making improvements in the baits, composing them out of
food sources that are essential for termite development--the right ratio of
carbohydrates, amino acids, fatty acids, mineral salts, and vitamins,"
says Lax. "We want to make formulations that are absolutely irresistible
to Formosan termites, so they'll have no choice but to take the bait--and the
toxin that goes along with it."
Elsewhere, collaborating scientists are pursuing other avenues of attack.
They include:
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Microbiologist Alan Lax examines
carton nest material on insulation and
framing damaged by the Formosan
subterranean termite.
(K8217-2) |
- Ken Grace, a University of Hawaii entomologist, is working to identify the
termite's favorite native species of trees and plants and those it avoids. The
bad-tasting plants may contain signaling chemicals that deter the termite from
feeding and could become part of new, biologically based pesticides.
- Roger Gold, a Texas A&M University professor at College Station, is
studying termite biology, reproduction, and foraging behaviors. Of chief
interest: the symbiotic relationship between the termite and protozoa that
reside in its hind gut. There, the microbes supply their insect host with
enzymes for digesting cellulose. Gold envisions a form of microbial sabotage in
which tricking the termite to ingest low doses of certain chemicals would kill
its protozoan partners. Starving the pest by this method, Gold notes, "is
quite a few years off."
- Janine Powell works with the ARS Biological Control and Mass Rearing
Research Unit at Mississippi State and the ARS Quarantine Facility at
Stoneville. Powell's charge is to coordinate research to find, collect, and
import the Formosan termite's natural enemies--whether they are predatory
insects, parasites, or fungi that infect and kill the pest. If such organisms
exist, scientists will return with specimens for study under quarantine
conditions at the Mississippi labs. If these natural enemies pass muster on a
rigid environmental safety checklist, scientists would place them on active
duty in termite-infested regions of the United States.
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New Orleans Mosquito and Termite
Control Board entomologist Ed Freytag
checks for Formosan termite infestation
of living trees in New Orleans'
Jackson Square.
(K8202-6) |
- Entomologist Rick Brenner at ARS' Center for Medical, Agricultural, and
Veterinary Entomology at Gainesville is leading research to harness the GIS
maps, along with Global Positioning System technology. Scientists will use
these high-tech tools to monitor the termite's spread, colony growth, foraging
patterns, and proximity to moisture sources. By illustrating areas of interest,
the GIS maps will help scientists identify termite hotspots where baits or
other controls would be most effective.
The SRRC is both research institution and the hub around which Operation
Full Stop scientists coordinate their studies and communicate findings. The
center also works closely with New Orleans' Audubon Institute, which fills a
vital educational role in enlisting public support and participation on the
project. In late 1999, the center plans to host an international conference to
report on the campaign's progress, as well as to highlight research results
from around the world.
With New Orleans as the proving ground, Operation Full Stop will eventually
expand to other states or cities under siege by the Formosan subterranean
termite. If unchecked, scientists fear the pest will extend its range, perhaps
along the coastal states of the North or West.
In this sense, Operation Full Stop is a good national insurance policy. In
the words of French Quarter resident June Cahn, "You would do very well in
settling the question down here before it gets to you."--By
Jan Suszkiw, Agricultural
Research Service Information Staff.
J. Patrick Jordan and
Alan R. Lax are at the USDA-ARS
Southern Regional
Research Center, 1100 Robert E. Lee Blvd., P.O. Box 19687, New Orleans, LA
70179; fax (504) 286-4234.
[Jordan] phone (504) 286-4212.
[Lax] phone (504) 286-4472.
For termite information on the WWW, visit
http://www.ars.usda.gov/is/br/fullstop/
"The Formosan Termite A Formidable Foe!" was published in
the October 1998 issue of Agricultural Research magazine. Click here to see this
issue's table of contents.
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