Michele C. Marra, Nicholas E. Piggott, and Barry K. Goodwin
North Carolina State University
Recently, one type of corn rootworm has developed resistance to a single strain of Bacillus thuringiensis (Bt) that is genetically engineered into corn seed. This resistance development has occurred in small, localized areas of the Corn Belt, where corn has been grown continuously for a period of time. Some have suggested that the remedy for this problem is to revert back to a significantly higher-percentage, structured refuge to avoid further resistance development. This article explores the economic consequences of such a plan. Those consequences include lower average corn yields, leading to higher corn prices for all consumers of corn (including livestock producers) and corn sweetener, ethanol producers, and consumers of corn globally; less net income for corn producers; higher yield variability, leading to higher price volatility; negative environmental impacts; and higher human-safety risks. A more balanced approach to the problem is recommended; this includes best management, integrated pest-management practices, a phasing out of single corn rootworm-traited corn, and increased use of multiple corn rootworm-traited corn.
Key words: Crop biotechnology economics, corn rootworm, refugia.