University of Illinois entomology professor Mike Gray’s research has confirmed a previous Iowa State University study indicating that rootworms, which are considered corn’s worst pest, have become resistant to a breed of Monsanto-produced genetically engineered corn.

Gray’s research involved analyzing adult rootworms from Illinois in Iowa State University labs and comparing the results to the previous study.

“It’s an unfortunate consequence of the overuse of good technology,” Gray says.

According to the USDA’s study on the adoption of genetically engineered crops in the United States, 88 percent of farmers in Illinois use genetically engineered corn; of the 88 percent, 50 percent use Cry3Bb1.

Gray said farmers should talk to their seed salesmen to see what they recommend to control the rootworm resistance. However, he said that because the rootworm problem began after farmers started growing corn or year after year in the same field, they could try alternating between planting corn and soybeans each year to deter pests.

Jorge Fernandez-Cornejo, USDA agricultural economist in the Resource and Rural Economics Division, offered a different solution for farmers who would like to continue using genetically modified corn.

“You need to separate part of the land without Bt corn, and there will be less resistance because of the refuge,” he said. “It’s what a lot of experts are suggesting.”

Here is Monsanto's response to these developments, issued Sept. 10, 2012:

"On Aug. 16th, at University of Illinois' Agronomy Day, entomology professor Mike Gray reported that he had confirmed resistance to Cry3Bb1 in two corn rootworm populations collected in northwestern Illinois in Henry and Whiteside counties in August 2011.

"Dr. Gray's research on these two populations is important in understanding the nature of resistance and in finding practical integrated pest management solutions for growers. We share a common vision with Dr. Gray and the academic community: We all want to ensure that modern insect-protection tools, such as Bt traits, remain a viable tool for farmers for years to come.

"While we do not have data to comment on Dr. Gray's research, this season we put in place a comprehensive program, including a series of aggressive best management practices (BMPs), to better assist farmers who reported unexpected damage to us in 2011. Grower adoption of our BMPs is in close alignment with Dr. Gray's recommendations - including rotating crops, rotating traits, and/or utilizing dual-mode-of-action products.

"The data from our assessment of these BMPs overwhelmingly demonstrate that farmers can easily and practically manage these few, field-localized cases of increased tolerance through both proactive and reactive measures. For example:

"Preliminary results clearly demonstrate that farmers will adopt the recommended BMPs and that the BMPs are providing very effective management of a field's corn rootworm population in the following season.

"BMPs are effectively controlling the corn rootworm population, and there is no evidence that the population is spreading. We are seeing fewer performance inquiries this year compared to last year.

"Overall, root damage scores consistently appear to be low - which means the scores are well below the level that could result in decreased yield or have a negative economic impact for growers.

"SmartStax is performing very well in fields that had observed corn rootworm damage in 2011, which is consistent with scientific mathematical modeling that supports the durability and use of SmartStax in fields that have previously experienced greater-than-expected corn rootworm damage."