Article: Cinnamon oil kills mosquitoes

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Passing along some interesting info ...

 

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Chris (list mom)

http://www.alittleolfactory.com

 

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http://www.eurekalert.org/pub_releases/2004-07/acs-ok071504.php

Public release date: 16-Jul-2004

 

Contact: Michael Bernstein

m_bernstein

202-872-6042

American Chemical Society <http://www.acs.org/>

 

 

Cinnamon oil kills mosquitoes

 

 

 

NOTE FOR REPORTERS: The statement in our original news release

(distributed 7-15) that cinnamon oil can " kill mosquito larvae more

effectively than DEET " is misleading since we neglected to point out

that DEET is most commonly used in insect repellants, not as a

larvicide. We apologize for not making this clear. Please disregard the

previous version of this news release and use the following version.

 

Cinnamon oil shows promise as a great-smelling, environmentally friendly

pesticide, with the ability to kill mosquito larvae, according to a new

study published in the July 14 issue of the Journal of Agricultural and

Food Chemistry, a peer-reviewed journal of the American Chemical

Society, the world's largest scientific society.

 

 

The researchers also expect that cinnamon oil could be a good mosquito

repellant, though they have not yet tested it against adult mosquitoes.

 

 

Besides being a summer nuisance, mosquitoes pose some major public

health problems, carrying such deadly agents as malaria, yellow fever

and West Nile virus. While conventional pesticide application is often

effective in controlling mosquito larvae before they hatch, repeated use

of these agents has raised serious environmental and health concerns.

 

 

" These problems have highlighted the need for new strategies for

mosquito larval control, " says Peter Shang-Tzen Chang, a professor in

the School of Forestry and Resource Conservation at National Taiwan

University and lead author of the paper. Scientists are increasingly

turning to more benign natural chemicals to ward off mosquitoes and

other pests.

 

 

Chang and his coworkers tested eleven compounds in cinnamon leaf oil for

their ability to kill emerging larvae of the yellow fever mosquito,

Aedes aegypti. " Four compounds - cinnamaldehyde, cinnamyl acetate,

eugenol and anethole - exhibited the strongest activity against A.

aegypti in 24 hours of testing, " Chang says.

 

 

Larvicidal activity is judged with a measurement called LC50. " The LC50

value is the concentration that kills 50 percent of mosquito larvae in

24 hours, " Chang explains. Lower LC50 translates into higher activity,

because it takes a lower concentration to kill larvae in the same amount

of time. All four compounds had LC50 values of less than 50 parts per

million (ppm), with cinnamaldehyde showing the strongest activity at an

LC50 of 29 ppm.

 

 

Other common essential oils, such as catnip, have shown similar promise

in fighting off mosquitoes, but this is the first time researchers have

demonstrated cinnamon's potential as a safe and effective pesticide,

according to Chang.

 

 

Cinnamaldehyde is the main constituent in cinnamon leaf oil and is used

worldwide as a food additive and flavoring agent. A formulation using

the compound could be sprayed just like a pesticide, but without the

potential for adverse health effects - plus the added bonus of a

pleasant smell.

 

 

Bark oil from the Cinnamomum cassia tree is the most common source of

cinnamaldehyde, but the tree used in this study - indigenous cinnamon,

or Cinnamomum osmophloeum - has been of interest to researchers because

the constituents of its leaf oil are similar to those of C. cassia bark

oil. The leaves of C. osmophloeum, which grows in Taiwan's natural

hardwood forests, could be a more economical and sustainable source of

cinnamon oil than isolating it from bark, Chang says.

 

 

Though the team only tested the oil against the yellow fever mosquito,

cinnamon oil should prove similarly lethal to the larvae of other

mosquito species, the researchers say. In further studies they plan to

test cinnamon oil against other types of mosquitoes as well as different

commercial pesticides.

 

 

" We think that cinnamon oil might also affect adult mosquitoes by acting

as a repellant, " Chang says. The researchers haven't yet tested this

theory, but they plan to find out in the near future.

 

 

The Council of Agriculture of the Executive Yuan, a government agency in

Taiwan, provided support for this research.

 

 

 

- Jason Gorss