Food Safety
TECH FLASH

Rootworm evolving to eat GMO corn, say scientists

The insects were unable to survive exposure to Bacillus thuringiensis-infected corn, but resistance has been growing.

March 26, 2014
/ Print / Reprints /
ShareMore
/ Text Size+

Rootworm evolving to eat GMO corn, say scientists

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 management practices have left the nation’s corn supply vulnerable to the pests, which are supposed to be unable to feed on the three varieties of GMO corn currently in use.

So-called BT corn was introduced in 1996 and contains genes of the Bacillus thuringiensis bacteria, making it poisonous to rootworms and corn borers. USDA says BT corn constitutes 75 percent of the nation’s corn crop. Consuming Bacillus thuringiensis should cause the cell walls in rootworms’ bodies to break down, resulting in death from septicemia.

However, concerns over effective management began to spring up almost immediately. In 2002, EPA recommended a 50 percent refuge requirement for non-BT corn to prevent BT resistance. Rootworms in these refuges would remain susceptible to the Bt toxin, and would prevent resistance from building up by mating with any Bt-resistant worms that evolved in neighboring fields.

However, pressure from industry led EPA to reduce the voluntary guidelines at a 20 percent refuge requirement. According to a 2003 report from Gregory Jaffe of the Biotechnology Project, 19 percent of farms did not comply with the refuge recommendation maximum, and 13 percent don’t plant refuges at all.

Then in 2009, Gassmann was alerted to extensive rootworm infestations in Iowa which suggested rootworms had become resistant to one of the three brands of BT corn on the market. In 2011, rootworm outbreaks were found in Illinois, Minnesota, Nebraska and South Dakota, states that are contiguous with Iowa. Gassman found evidence that resistance to one variety of BT corn heightened the chances of resistance to another, meaning corn engineered to contain multiple BT toxins won’t be as effective as had been hoped.

There is no evidence that BT corn has become ineffective against other pests, so farmers will likely continue to use it. However, Gassman says, farmers will likely turn to pesticides to rid their crops of rootworms, which increases costs and mitigates the ecological benefits of BT corn.

Did you enjoy this article? Click here to subscribe to Food Engineering Magazine.

Recent Articles by Shane O'Halloran

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

Plant of the Year 2014

Blue Diamond Growers was chosen as Food Engineering's 2014 Plant of the Year. The Sacramento-based company is the world’s largest producer of almonds and almond ingredients.

Podcasts

Burns & McDonnell project manager RJ Hope and senior project engineer Justin Hamilton discuss the distinctions between Food Safety and Food Defense as well as the implications for food manufacturers of the Food Safety Modernization Act.
More Podcasts

FSMA Audit

What is the is most important step you have taken to become ready for a FSMA audit?
View Results Poll Archive

Food Engineering

FE September 2014

2014 September

The September 2014 issue of Food Engineering explores how lean manufacturing, quality improvements and increased automation helps processors meet rapidly changing demands. Also, read how robotics, advanced machine controls, software and OEE are just a few of the tools that can boost productivity on packaging lines.

Table Of Contents Subscribe

THE FOOD ENGINEERING STORE

Food-Authentication-Flyer-(.gif
Food Authentication Using Bioorganic Molecules

This text provides critical tools and data needed to augment routine food analysis and enhance food safety by aiding in the detection of counterfeit, and potentially deleterious, foods.

More Products

Clear Seas Research

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications,Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

Food Master

Food Master Cover 2014Food Master 2014 is now available!

Where the buying process begins in the food and beverage manufacturing market. 

Visit www.foodmaster.com to learn more.

STAY CONNECTED

FE recent tweets

facebook_40.pngtwitter_40px.pngyoutube_40px.png linkedin_40px.pngGoogle +