Pesticide and Environmental Update
Japanese Mint Could Lead to Environmentally Friendly Fumigant
News Service Agricultural Research Service, USDA
Kathryn Barry Stelljes, (510) 559-6069,
Asian spices may lead to an environmentally friendly method of pest control in stored grains.
Researchers at ARS' Western Regional Research Center in Albany, Calif., tested the oils extracted from 16 spices and medicinal plants for effects on the rice weevil (Sitophilus oryzae). Japanese mint (Mentha arvensis) contained the most potent oils against the weevil. The active ingredient, menthone, could provide the basis for a new fumigant.
Rice weevils are one of the chief stored-grain pests worldwide. The 1/8th-inch-long weevils bore into the grains and consume the kernel, reducing the nutritional value and germination ability of the grain. They also expose the grain to further degradation by odors, molds and heat.
Many key components of currently used fumigants are losing their federal registrations because of environmental concerns. Insects have also begun to develop resistance to some widely used fumigants.
Scientists feel that menthone-based fumigation has good potential as a stored-grain fumigant. It would leave no hazardous residues, would not adversely affect the nutritional quality or processing characteristics of stored grain, would not be flammable or corrosive and would be easily removable by aeration. Additional testing would need to be conducted to determine the impact of menthone on odor and flavor.
ARS is the chief scientific research agency of the U.S. Department of Agriculture. Entomologist Bruce C. Campbell led the rice-weevil studies at the Albany research center's Plant Protection Research Unit, on the web at: http://www.pw.usda.gov/wrrcpagedoc/ORG/Org42.html