Read: a full report in Agricultural Research.

Corn Contains “Eggs-citing” Biopesticide

An egg white protein called avidin can give corn insect resistance that lasts from the field to the storage bin. Unlike chemical insecticides that can be washed off by rain or inactivated by ultraviolet rays, avidin works regardless of the weather.

Agricultural Research Service chemist Karl J. Kramer and colleagues at the Grain Marketing and Production Research Center in Manhattan, Kan., were the first researchers to report avidin’s lethal effect on stored-product beetles and moths. Each year, insects damage stored commodities--corn, wheat, rice, and grain sorghum-- causing multimillion-dollar losses. In 1994, the U.S. Department of Agriculture began a national integrated pest management initiative. ARS researchers have been developing nonchemical alternatives for controlling insect pests, weeds, and crop diseases.

Avidin sequesters biotin, a vitamin essential for insect growth. Feeding insects avidin produces a vitamin deficiency that leads to stunted growth and death. These studies come out of a partnership between ARS and ProdiGene, in College Station, Texas. ProdiGene produces transgenic corn with avidin. ARS researchers monitor how much avidin is needed to effectively kill insect pests. Cornmeal made from avidin corn resisted insect pests, demonstrating that products made from avidin corn will have a longer shelf life. That means corn farmers can sell higher quality corn that can be stored longer without pesticides.

Although avidin is already a common protein in human diets, the Food and Drug Administration will require a thorough risk assessment of avidin corn before approving it for food or feed.

For a full report, see the August issue of Agricultural Research magazine.

ARS is the chief research agency for the U.S. Department of Agriculture.

Scientific contact: Karl J. Kramer, ARS Grain Marketing and Production Research Center, Manhattan, Kan., phone (785) 776-2711, kramer@usgrml.ksu.edu.