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Did Termites Help Katrina Destroy New Orleans Floodwalls?
New research
presented in the fall issue of American Entomologist suggests Formosan
subterranean termites damaged New Orleans dikes.
Lanham, MD;
October 14, 2008—Three years after Hurricane Katrina devastated New Orleans,
people still speculate over causes of the destruction of the city’s floodwall
system. A new article in the fall issue of American Entomologist (Vol.
54, No. 3) suggests that Formosan subterranean termites played a large role.
Author Gregg
Henderson, a professor at the Louisiana State University AgCenter, discovered
Formosan subterranean termites (Coptotermes formosanus Shiraki) in the
floodwall seams in August, 2000 – five years before Katrina struck – and noticed
that the seams were made of waste residue from processed sugarcane. Known as
bagasse, this waste residue is attractive to Formosan termites.
After the dikes
were breached in 2005, Henderson and his colleague Alan Morgan inspected 100
seams for evidence of termites, including three areas where major breaks in the
walls had occurred. 70% of the seams in the London Avenue Canal, which
experienced two major breaks during Katrina, showed evidence of insect attack,
as did 27% of seams inspected in the walls of the 17th Street Canal.
The Formosan
subterranean termite originates from China, where it has been known to damage
levees since the 1950s. Besides eating at bagasse seams, the termites may have
contributed to the destruction of the levees of New Orleans by digging networks
of tunnels, which can cause “piping,” sending water through the tunnels and
undermining the levee system.
“I believe that
the termites pose a continuing danger that requires immediate attention,”
Henderson writes. “The fact that termites cause piping in levees must be
accepted.”
The author
further suggests that New Orleans’ 350 miles of levees and floodwalls should be
surveyed for termite damage, and that treatment of the floodwalls and nearby
trees may be necessary to avoid future disasters. Henderson will demonstrate one
survey method using ground-penetrating radar at the ESA Annual Meeting in Reno,
Nevada, November 16-19 (see
http://www.entsoc.org/am/cm/index.htm).
American
Entomologist
is published quarterly by the Entomological Society of America (ESA). Founded in
1889, ESA is a non-profit organization committed to serving the scientific and
professional needs of nearly 6,000 entomologists and individuals in related
disciplines. ESA's membership includes representatives from educational
institutions, government, health agencies, and private industry. More
information on ESA and the Annual Meeting is available at
www.entsoc.org.
Contact:
Richard Levine, 301-731-4535, ext. 3009, or
rlevine@entsoc.org.
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