Duping pests
a recent study could have broad implications for farmers' ability to stop pests from becoming resistant to pesticides. Scientists from the us-based North Carolina State University have found that in the us, cotton pests mature feeding on corn all summer before moving towards south to munch cotton in the autumn. Therefore, researchers say, if large quantities of pesticides are used in the corn fields, pests would move to the more commercially significant cotton fields armed with resistance to these pesticides.
A large amount of cotton grown in the us is genetically modified to contain the Bt gene from the bacterium Bacillus thuringiensis. This enables the plant to produce a toxin that is lethal to many pests. It is estimated that about 80-95 per cent of cotton bollworms (the predominant cotton pests) are killed by the Bt toxin. However, long-term exposure to Bt can make the pests resistant to it. Therefore, farmers grow