- According to a recent paper in the Proceedings of the National Academy of Scientists, corn rootworms may be evolving rapidly to develop a tolerance to GMO corn.
- Aaron Gassmann, an Iowa State University entomologist, warns that, consequently, the GMO corn introduced in 1996, as a solution to the problem, can become vulnerable to pests.
- BT corn, which now makes up 75% of the nation's corn, contains genes of the Bacillus thuringiensis bacteria, making it poisonous to rootworms and corn borers. Nevertheless, extensive rootworm infestations in Iowa indicate rootworms have developed tolerance to at least one of the three brands of BT corn on the market.
This doesn't mean that farmers will consider genetically modified corn to have lost any edge over the non-GMO varieties, for it still is effective against other pests. However, it does lose some of its value if farmers have to purchase and apply additional pesticides to treat their crops' rootworm. That constitutes both an economic and environmental cost, for one of the benefits of building anti-pest properties into seeds is mitigating the use of toxins on fields. For those who were considering going non-GMO to appeal to the customers who demand it, this will be one more push in that direction.