Research team finds that natural enemies help delay insecticide resistance, protect Bt crops

Despite the controversy over them, transgenic crops have helped growers fend off some of the most destructive pests. The higher yield that results has provided consumers more affordable food. When used properly as a part of an integrated pest management program, transgenic crops can be an effective and economical way to manage certain pests, diseases and weeds. Unfortunately, as the failures of Roundup Ready crops have shown, transgenic crops are not sustainable when used as the sole pest management tactic.

When Bt technology came out, the Environmental Protection Agency instituted a requirement to have a “refuge” plot of crops not protected with Bt to maintain a population of pests that were not exposed to the Bt toxin. The refuge could be treated with an insecticide; it just couldn’t be treated with Bt. The theory behind the refuge was that having a plot of the crop that was treated with a different insecticide would give the pest species a non-Bt alternative, so that those individuals would still be susceptible to Bt, mate with individuals who had been exposed to Bt and pass on their Bt-susceptible genes to the next generation, therefore delaying resistance. Continue reading

Are Bt Crops a Silver Bullet or a Looming Disaster?

Cotton growers know the pest as the bollworm. Corn growers call it corn earworm. Tomato growers don it tomato fruitworm. By any name, the pest is Helicoverpa zea, and it’s the first pest to develop resistance to Bacillus thuringiensis.

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