Twenty years ago, when I was still a staff reporter at the local, daily newspaper, I interviewed a professor of agriculture at the University of Guelph. At the end of the interview about a certain issue of interest to local farmers, I mentioned I was also a small-scale market gardener who tried to use organic methods. They included the use of bacillus thuringiensis (Bt) to control the caterpillar stage of certain lepidopteran (moth and butterflies) insects that feed on corn, potatoes, tomatoes and other crops. I told her I had recently learned U.S. government Environmental Protection (EPA) regulators had approved the genetic engineering of Bt with corn and wondered what she thought.
I will never forget her comment in response to my question: “Nature abhors a vacuum,” she said, adding “sooner or later” the bugs will develop resistance.
Over the years since then as the use of Bt hybrid corn, and other Bt genetically modified crop seeds, has steadily and greatly increased in the U.S. especially, and in Canada and 16 countries, I have wondered when what she said would happen.
I got the answer a few days ago when I found the latest issue of the Ontario farm-information newspaper, Farmtario, in my mailbox: it has already started to happen — a couple of years ago, in fact; and government regulators in the U.S. and Canada are now considering regulatory changes in hopes of stopping or slowing down the advance of Bt-resistant super bugs. The use of ‘super’ there is my choice of word, because as far as I’m concerned that’s what it amounts to if Bt is no longer useful as an organic solution.
The Farmtario article was perhaps not strictly speaking ‘breaking news’ and therefore worthy of front-page coverage, other than a teaser that referred to an article on Page 10 about ‘The challenge with Bt.’
And it was written in a way that would make it difficult for non-farmer consumers to understand what it’s about. I’m not saying that’s deliberate. And after all, Farmtario is aimed at farmers, so presumably there’s apparently an assumption they know what the jargon like “Bt hybrid corn” means. But, it’s not a hybrid in the traditional sense of cross-breeding different species of the same type of plant to create a new hybrid variety. That’s been done for thousands of years, not 20. “Bt hybrid corn” is misnomer camouflage to hide what it really is: Bt Genetically Modified Organism (GMO) corn.
The “challenge” referred to by the Farmtario article is rooted in the fact more than 90 percent of corn grown in the U.S. is ‘Bt hybrid.’ The same is true of Bt hybrid cotton. Evidence of growing resistance to Bt ‘traits’ has been reported in recent years and recently confirmed, according to an EPA discussion paper regarding proposed changes to regulations now being considered. They include “compliance assurance” from growers and annual reporting.
The EPA says changes are needed to bring the growth of resistant insect pests under control; otherwise, “if resistance continue to proliferate, Bt corn and cotton could be lost to farmers as tools to address pest problems.”
Meanwhile, similar concerns have been raised in Canada, since the first resistance to Bt corn, involving a European corn borer infestation was confirmed in Nova Scotia last year. “This is the first report in the world of the European corn borer (ECB) developing resistance to a genetically engineered trait used to confer insect resistance. It is also the first report in Canada of any insect pest developing resistance to a genetically engineered trait. The development of resistance in other insect pests targeted by Bt (Bacillus thuringiensis) traits in corn has been observed in the U.S., South Africa and Brazil,” the Canadian Biotechnology Action Network (CBAN) reported in June, 2019.
“This is an important reminder that nature can adapt to and overcome genetically engineered traits,” said CBAN’s Lucy Sharratt.
That’s putting it mildly. Say what you want about the ethics of modern genetic engineering, or modification, but from my point of view, the real tragedy here is the loss of Bt as a bona fide, organic control of the damage European corn borer, corn earworm and corn rootworm can cause.
Bacillus Thuringiensis occurs naturally in soil. It poses no risk for human consumption. It has been used by market-garden farmers and gardeners for many years. I have used a liquid concentrate sold under the name BTK for 30 years with excellent results. I have found it is indispensable, to avoid damage rendering the corn unsaleable and repugnant. But I try in my modest way to take a responsible, Integrated Pest Management (IPM) approach. That always involves checking for corn borer when the corn plants are about half a metre high, and then unwinding the whorl of a few and carefully looking for the tiny larvae. If none, I don’t spray. With corn earworm, wait until the silk has begun to form before spraying. Wait another two weeks before spraying again. That’s usually enough.
As for the massive, widespread use of Bt GMO corn, and the subsequent appearance of resistant bugs, it should have been obvious what was going to happen when it was approved.