The effectiveness of pesticides against mosquitoes, another group
is learning how repellents work.
At the Agricultural Research Service (ARS) Center for Medical,
Agricultural and Veterinary Entomology (CMAVE) in Gainesville, Fla.,
entomologist Sandra Allan is using toxic sugar-based baits to lure and kill
mosquitoes. Allan and her CMAVE cooperators are evaluating insecticides and
designing innovative technology to fight biting insects and arthropods. ARS is
USDA's principal intramural scientific research agency.
Allan studied 10 different commercial pesticides that contain
additives that enable the pesticides to be dissolved in water and ingested by
mosquitoes. Pesticides were combined with a sucrose solution and fed to females
of three mosquito species that transmit pathogens such as West Nile virus and
arboviruses. While only females feed on blood, all mosquitoes need to feed on
sugar and will potentially be attracted to -- and ingest -- the toxic sugar
bait.
Compounds from five different classes of insecticide-active
ingredients -- pyrethroids, phenylpyroles, pyrroles, neonicotinoids and
macrocyclic lactones -- were found to be toxic against all three mosquito
species,Culex quinquefasciatus, Anopheles quadrimaculatus and Aedes
taeniorhynchus.
Scientists at the ARS Henry A. Wallace Beltsville Agricultural
Research Center in Beltsville, Md., are learning more about how mosquito
repellents work. Entomologist Joseph Dickens and post-doctoral research
associate Jonathan Bohbot found that several repellents -- DEET, 2-undecanone,
IR3535 and picaridin -- affect specific odorant receptors in mosquitoes
differently, thereby scrambling the insect's ability to detect chemical
attractants.
In experiments, they injected frog eggs with odorant receptor
genes. Molecular mechanisms within the eggs allowed these receptors to be
reproduced in the outer cell membrane of the egg. Researchers then placed
electrodes in the outer cell membrane and recorded electrical responses of the
odorant receptors to chemical solutions.
Source:
The above story is reprinted from materials provided by United
States Department of Agriculture - Research, Education and Economics.
The original article was written by Sandra Avant.
Note: Materials may be edited for content and length.
For further information, please contact the source cited above.
Disclaimer: This article is not intended to provide
medical advice, diagnosis or treatment. Views expressed here do not necessarily
reflect those of Eagle Group or its staff.
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