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Above: A new device that permits researchers to compare five different doses of insect repellents--along with a control. The device, the K&D Module, was designed by Drs. Klun and Debboun. (Image courtesy J. Klun. Not available at 300 dpi resolution)

Promising New Compound for Fending Off Insects

A new chemical compound developed cooperatively by scientists with the Agricultural Research Service and the U.S. Department of Defense looks promising as the key active ingredient in new, safe insect repellents for U.S. military personnel and eventually for the general public. ARS has patented the new compound, called SS220, and it is currently undergoing toxicology tests required for registration with the U.S. Environmental Protection Agency.

ARS, USDA's chief in-house scientific research agency, has several specialized laboratories with expertise in studying biting insects such as mosquitoes, ticks and flies that can transmit diseases to humans.

DOD launched a Strategic Technology Objective three years ago to identify and develop a new standard military insect repellent to replace DEET, a repellent developed 50 years ago by ARS for the military. DEET is the most widely used repellent in the world and has prevented uncounted cases of malaria and other vector-borne diseases in both civilians and military. During the research project, researchers sought a new repellent effective against a wider range of mosquito species, and compatible with commonly used plastics such as in eyeglass frames and military equipment.

The Strategic Technology Objective involved representatives of the Department of Entomology of the Walter Reed Army Institute of Research (WRAIR) in Silver Spring, Md., and ARS' Chemicals Affecting Insect Behavior Laboratory (CAIBL), which is part of the ARS Henry A. Wallace Beltsville (Md.) Agricultural Research Center.

Entomologist Jerome A. Klun, who heads the CAIBL team working with the military's infectious disease research program, collaborated with WRAIR's Mustapha Debboun, a medical entomologist, to develop a clear, six-chamber device with which to safely screen candidate compounds on human volunteers' skin. Preliminary laboratory tests involved the controlled release of lab-reared, disease-free mosquitoes over treated skin to demonstrate the compound's protective qualities. The team will now test the ingredient's staying power through vigorous activity and exposure to water in the field. The initiative aims to further refine the cosmetic aspects of SS220 formulations.

SS220 is a highly effective chemical compound, called a stereo isomer, which Klun isolated from a mixture of compounds that was first synthesized by ARS scientists in 1978. CAIBL's chemical team developed a three-step process which led to preparation of large quantities of SS220 required for testing.

The ARS Office of Technology Transfer (OTT) will license the USDA technology under policies set forth in the Federal Technology Transfer Act. Companies interested in licensing this USDA technology can obtain a license application online or from the OTT.