Reports have been coming in of a world wide failure and the evolution of insects that are no longer susceptible to the genetically engineered corn.
A recently published study in the Journal of Biotechnology, that analyzed the findings of 77 studies and eight countries from field data points to a common factor, the evolution of insects resistant to GM crops.
Of 13 major pest species examined, five were resistant by 2011, compared with only one in 2005, they found. The benchmark was resistance among more than 50 percent of insects in a location. Of the five species, three were cotton pests and two were corn pests. Three of the five cases of resistance were in the United States, which accounts for roughly half of BT crop plantings, while the others were in South Africa and India.
There are also early warning signs from four other cotton or corn pests in China, the U.S. and the Philippines. The speed at which resistance developed was dependent upon the planting of non-BT crops on refugee land, as the genes that confer resistance are recessive, meaning that insects can survive on BT plants only if they have two copies of a resistance gene — one from each parent. Planting refugees near BT crops reduces the chances of two resistant insects mating and conferring the double gene to their offspring.
In Africa and South Africa one of the most destructive maize pests – the stalk borer – has figured out a way of safely feeding on genetically modified crops even when farmers apply the refugee land strategy in managing the new generation of hard-to-kill insects.