Jun 30 2015

Lessons From GM Wheat Failure

So-called “whiffy wheat” was genetically modified to release a pheromone that repels aphids. The obvious purpose of this modification was to reduce pests without the need for insecticides, and thereby reduce insecticide use.

The trait worked well in the lab. The wheat released sufficient amounts of a warning pheromone that aphids release when attacked. The pheromone both warns aphids to stay away, and also attracts predators, such as a parasitic wasp. The pheromone was derived from the peppermint plant.

The laboratory success meant the wheat was ready for field trials where the GM crop is put to the test in close to real world conditions. The results of those field trials were just published, and unfortunately they showed that the new trait essentially didn’t work – the aphids were not significantly decreased compared to controls, nor was yield increased.

The scientists discuss a few possible reasons for the failure. One is that during the field trials, cold wet summers made for low baseline levels of aphids, below the threshold where fields would normally be sprayed. There was therefore not much room for improvement, but still if the trait worked it should have been evident.

They also report that the aphids demonstrated habituation in the lab, meaning they were less effected by the pheromone over time. Finally the scientists speculate that the failure may be due to the timing of release. When aphids are attacked they release the pheromone in a burst. The wheat, however, released it in a slow and continuous manner. Perhaps they have to engineer the wheat to release the pheromone in larger amounts in a short period of time.

The researchers believe that this approach, using pheromones to repel insects and/or attract natural predators, has promise. This specific application needs to go back to the drawing board, however.

What is more interesting than the study itself is how different people responded to it. Scientist reacting with statements to the effect that negative results are still results, we need to accept the data even if it is not what we want, and now we can take what we learned and move forward.

Dr. Toby Bruce, first author on the study, is quoted as saying:

“This trial has ended up yielding more questions than answers, but that means we have more work to do to understand the insect-plant interaction and to better mimic what happens in nature.”

Anti-GMO activists, however, are using this one failure of one GM variety as if it represents the failure of the entire concept of genetic modification. The same BBC article quotes Liz O’Neill, director of GM Freeze, as saying:

“The waste of over £1m of public funding on a trial confirms the simple fact that when GM tries to outwit nature, nature adapts in response.”

That is interesting the O’Neill is concerned about the waste of public funding, because, as Nature reports:

The protests did not disrupt the research, but making the site secure added around £1.8 million (US$2.8 million) to the study’s research cost of £732,000.

Protests from groups like GM Freeze, who have vandalized field trials of GM crops, cost more than twice as much because of needed security than the trial itself. It’s more than a bit disingenuous to complain about the cost of such trials now. She goes on to say:

 “The truth is that nature is just too complex for the simplistic thinking behind GM.

“Meanwhile, we are crying out for investment in proven solutions like integrated pest management, companion cropping, conventional plant breeding, and novel chemistry.

Sure, nature is complex and adaptive. That is a inherent challenge of all agriculture, which in itself is inherently “unnatural.” She is drawing a false dichotomy, however, between the methods she mentions and GM technology – GM is just one method that can be successfully incorporated into things like integrated pest management.

Further, methods that are ideologically preferred by organic growers and anti-GM activists are themselves susceptible to the same limitation, the complexity of the ecosystem and the tendency for nature to adapt. They do not magically make these problems disappear.

I do have to wonder what the attitude of those like O’Neil would be toward a pest management system that includes spraying wheat with a natural pheromone derived from the peppermint plant that repels aphids, attracts natural predators, and thereby reduces the need for pesticide. I doubt they would be decrying this approach as overly simplistic and be calling to abandon the entire technology.


There are several lessons from this latest episode in the battle over GMO.  One is that there is a real price tag attached to the vandalism used by some anti-GM activists. In this case adding £1.8 million to a field trial that would otherwise have cost only £732,000.

This is a common tactic employed by many anti-science activists – creating a problem and then using that very problem they create as an argument against the science they oppose.

A second lesson is that GM scientists appear to be doing honest science, at least in this case. They genuinely want to find solutions that work, and if field trials are negative, they publish the negative results and move on. This is not a small point, as anti-science rhetoric is often tinged with conspiracy thinking, and the results of positive studies are often dismissed as fraud (without any evidence).

Finally, this is further evidence that the anti-GMO crowd do not have a coherent position. Their arguments against GMO largely come down to “it ain’t natural.” They also create a straw man comprising a false dichotomy between GM technology and other agricultural methods.

There is general agreement that sustainable methods of agriculture are needed, and that some form of integrated pest management is best. Nature is complex and adaptive, and therefore if we are going to try to squeeze as much food production out of as few resources as possible, in a sustainable way, we need to use a variety of techniques and technologies.

GM can be one of those technologies. It is not a panacea, but it has certain advantages over other methods. We should be using the best options available in a rational and evidence-based way.

Anti-GMO activism, however, is based on ideology, not evidence or reason.

This is usually the point at which many of those who are anti-GMO would state that the “real” reason they oppose GMO is because they are against corporate power, patents, etc. If that is the case, then you are fighting the wrong battle. As I and others have pointed out, your problem is not with GM technology but with regulations.

I would also point out that many of the anti-corporate talking points are simply false. They are based on misinformation and propaganda, so if you are going to take that position definitely make sure you have your facts right. (For example, Monsanto does not sue farmers for seeds blown onto their land, they do not market terminator seeds, and GM crops have not caused suicides in India.)

I do not know if this approach, using pheromones to repel pests, will pan out as a useful strategy. Neither do the scientists, or the anti-GMO activists. It is an interesting concept, and it seems to me is sufficiently reasonable to warrant the relatively small amount of investment to do the research. This kind of research may also yield unanticipated benefits. Let’s do the science and find out.

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