Plant Essential Oil Eyed as Mosquito, Ant
August 24, 2009
Agricultural Research Service (ARS)
scientists have teamed up with researchers from a company in American Samoa to
investigate the chemical makeup of a mosquito- and ant-repellent essential oil
from a native Samoan plant.
The ARS scientists and researchers at Agro Research, Inc., in Pago Pago,
American Samoa, discovered that the oil from a local plant repelled mosquitoes
and pest ants in preliminary studies, which were conducted under a material
transfer agreement. The isolation and identification of the active component
(or components) will be done as part of a recently established one-year
cooperative research and development agreement.
The plant is one of the 540 native species of flowering plants in American
Samoa, a U.S. island territory in the South Pacific.
Vander Meer and
Bernier at the agencys
for Medical, Agricultural and Veterinary Entomology in Gainesville, Fla.,
are working with Agro Research, Inc.s Pemerika Tauiliili to identify the
active ingredients in the plant essential oil.
Two mosquito speciesAedes aegypti and Anopheles
albimanuswere used to evaluate the essential oils repellency.
A. aegypti transmits viruses that cause yellow fever, dengue and
chikungunya. A. albimanus transmits malaria parasites and is not as
susceptible to repellents as many other mosquito species.
The essential oil was also tested on the red imported fire ant,
Solenopsis invicta. Significant repellency was observed with
concentrations diluted more than 100-fold, and the active components are likely
a small fraction of the total oil.
While American Samoa is malaria-free, mosquitoes pose significant problems
for the Samoan population due to transmission of dengue virus.
Exploration for new active ingredients among botanical extracts has value
because it can lead to the discovery of new synthetic analogs with unique and
ARS is the principal intramural scientific research agency in the
U.S. Department of Agriculture.