story to find out more.
Berries and leaves of American beautyberry,
Callicarpa americana, on Pinedale Farm, the Mississippi farm once owned
by John Rives Crumpton, grandfather of ARS botanist Charles T. Bryson.
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A Granddad's Advice May Help Thwart Mosquitoes
By Luis Pons
January 31, 2006
Regional wisdom passed on long ago
to a boy who grew up to be an Agricultural Research Service (ARS) scientist could lead to the next
breakthrough against mosquitoes.
T. Bryson, was told by his grandfather John Rives Crumpton that fresh,
crushed leaves of American beautyberry, Callicarpa americana, helped
keep biting insects away from draft animals such as horses and mules.
According to Bryson, a botanist in ARS
Weed Science Research Unit at Stoneville, Miss., it was known among folks
in northeastern Mississippi during the early 20th century that placing the
crushed leaves under an animals harness would mash out a repellant oil.
Eventually, some people there started mashing the leaves and rubbing the
residue on their own skins.
Bryson later shared this knowledge with colleagues in ARS'
Products Utilization Research Unit at Oxford, Miss, where chemist
Cantrell studied the American beautyberry to see what it is about it that
mosquitoes don't like.
Cantrell, working with entomologist
Klun of ARS
Affecting Insect Behavior Research Unit in Beltsville, Md., and Oxford
Duke, isolated several insect-repelling compounds from the plant.
Among these was callicarpenal, which may represent ARS next important
anti-mosquito compound. ARS recently developed SS220, a repellent thats
just as effective as DEET, the worlds most-used insect repellent. DEET
was developed by ARS and the U.S. Army
According to Cantrell, isolated callicarpenal was as effective in laboratory
tests as SS220 in preventing mosquito bites. Those tests were conducted by Klun
against the mosquito species Aedes aegypti, which is best known
as the yellow-fever mosquito, and Anopheles stephensi, which spreads
malaria in Asia.
Cantrell said that a provisional patent application has been submitted for
callicarpenal, and that toxicity trials will precede any testing on humans.
more about the research in the February 2006 issue of Agricultural
ARS is the U.S. Department of
Agriculture's chief scientific research agency.