termite. Click the image for more information about it.
Natural Plant Extracts Seem Deadly to Formosan
Termites By Luis
Pons April 26, 2005
Wild celery and two weed species found throughout the western United
States may contribute to safe, natural control of the Formosan subterranean
termite, Coptotermes formosanus.
Agricultural Research Service (ARS) scientists say that, in lab tests,
three compounds that they isolated from these plants scored high kill rates
against the invasive termites, which cause about $1 billion in damage annually
in the United States.
One compound, called apiol, was extracted from wild celery
(Ligusticum hultenii), which is actually a member of the parsley family.
The other compounds are cnicin, which was isolated from spotted knapweed
(Centaurea maculosa), and vulgarone B, taken from Artemisia
douglasiana, a variant of mugwort.
The compounds were isolated and identified by chemist
M. Meepagala at ARS'
Products Utilization Research Unit in Oxford, Miss. Entomologist
Osbrink at ARS'
Subterranean Termite Research Unit in New Orleans, La., tested them for
In those tests, Osbrink, whose unit is part of ARS'
Regional Research Center, found that vulgarone B and apiol are lethal and
fast-acting to the termites. By the fourth day after application, vulgarone B
achieved a 97 percent mortality rate, and apiol had an 80 percent rate. Both
achieved 100 percent kill rates by the fifteenth day after application.
Cnicin was slower acting, with an 81 percent mortality rate 15 days
after the treatment.
According to Meepagala, these compounds were present in high levels in
the plants from which they were isolated. The spotted knapweed from which the
cnicin was taken is a highly invasive weed in the northwestern United States,
while Artemisia douglasiana is found in all of the western states.
Meepagala had previously shown that vulgarone B is an effective and
fast-acting natural control of golden apple snails, which devastate Asian rice
ARS is the U.S. Department of
Agriculture's chief scientific research agency.