A molecular pesticide, in which nucleic acid is the active ingredient, prevents a mosquito from making proteins necessary for survival. Above, a mosquito gets a blood meal. Click the image for more information about it.

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New Nonchemical Approach to Curbing Mosquitoes

By Sharon Durham
December 20, 2007

Most pesticides are toxic to insects and humans alike, but a molecular pesticide developed by Agricultural Research Service (ARS) scientists may provide a new way to deal with mosquito pests without causing a risk to human health.

The molecular pesticide technology would also overcome the mosquito's ability to develop resistance to particular pesticides. A molecular pesticide has nucleic acid, such as DNA or RNA, as its active ingredient. The technology also has potential to be used against other insect pests.

The technology was developed by ARS entomologists Julia W. Pridgeon and James J. Becnel, in the ARS Mosquito and Fly Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Fla. Their technology prevents mosquitoes from producing essential proteins necessary for their survival. Although other approaches to nonchemical pest control are being pursued, this ARS invention has certain advantages.

The molecular pesticide concept allows scientists to design each pesticide specifically for the targeted individual pest species. It interrupts genes essential for insect survival, causing the insect to die. This recently discovered technology maximizes safety and minimizes environmental impact on beneficial insects.

In addition, molecular pesticides should be effective against pest species that are resistant to conventional chemical pesticides. Chemical pesticides often have an impact on the physiological systems shared by humans, but this new method only targets specific genes of the pest species. Molecular pesticides can also be easily administered—by contacting the insect externally.

This technology would also reduce the time and costs associated with obtaining regulatory approval of new products and would also serve as a model system for developing novel insecticides. Successful development and transfer of molecular pesticides could represent a quantum leap in developing new toxicants for pest control.

A patent application for this technology has been submitted and ARS is seeking a cooperative research and development partner to develop appropriate formulations that can be marketed and sold commercially. This research was partially funded by the Deployed War-Fighter Protection Research Program funded from the U.S. Department of Defense.

ARS is the U.S. Department of Agriculture's chief scientific research agency.