GM-fed butterflies don't fly

July 2016
Camelina: Photo Creative Commons
The UK government continues to promote GM crops as a rising star of industry. This isn't because it's enthralled by the herbicide-accumulating or insecticide-generating GM animal feed crops with which Big Biotech has filled overseas fields.

Westminster has its eye on high-value 'nutritionally-enhanced' GM offerings.

Most advanced of these novel crops is Rothamsted Research's GM camelina ('false flax') with fish-oil. Fish oil is rich in omega-3 fatty acids, 'EPA' and 'DHA', which are vital dietary components in the diet of both fish and humans. Fish get their omega-3s from eating algae, which are the main primary producers, or from eating other fish feeding on the algae. Humans can most easily get a healthy dose of omega-3s from eating fish.

Fish farms use huge supplies of wild, non-edible fish or fish-oil-supplemented feed, both of which are in short supply and neither of which is sustainable.

Enter Rothamsted with its (patented) "new and sustainable sources of healthy omega-3 fish oils for the fish industry to reduce the burden on marine fish oil stocks", hailed by its developer as "a landmark moment in the effort to develop truly sustainable sources of feed for fish farms."

Fish-oil-enriched GM camelina is about to enter its third year of open-air field trials.

At last, the healthy and sustainable GMOs we've been promised for two decades?

Well, good news for some, shame about the birds, the bees and the butterflies.

The problem is that animals (including humans) that need EPA/DHA omega-3s get them by eating other animals in a food-chain which starts with algae. Animals without this requirement feed off plants or other plant-eating animals. Most of the animals in our ecosystem, such as insects and insect-eating birds, fall into the latter category. If you put fish-oil in a plant, the birds, the bees and the butterflies will eat it. Remember what happened to the brains of cows and humans when we started feeding animal protein to naturally vegetarian animals?

Noting that "the effect of EPA and DHA on growth, development, and/or reproduction of terrestrial insects is unknown", a team of Canadian scientists had a look at what happened to cabbage white butterflies who had eaten omega-3s.

Cabbage white butterfly caterpillars were fed a diet supplemented with up to one percent EPA/DHA oil. This level was estimated to be realistic in GM camelina leaves (Rothamstead has provided no actual data). Since cabbage-whites also eat young pods which will have a much higher fatty-acid content, the experiment didn't model a worse-case scenario.

No effects were observed in the caterpillars. However, the adults emerging from the novel-oil fed caterpillars exhibited a dose-dependent weight increase, reduced (up to 50%) wing size, and increased incidence of wing deformity or dysfunction. The long-term effects weren't studied, but any one of these changes will reduce the fitness of the animals.

Total body fat increased with EPA/DHA dosage at lower dietary levels, but at the highest dose, the butterflies' body fat reduced, suggesting a toxic effect had kicked in.

The mechanism of the observed increases in body weight and wing deformity isn't known. However, the authors point out that fatty acid processing and incorporation into specific tissues are tightly regulated processes, and that such precision is likely required for optimum functionality of the tissue. Novel fatty acid elements in the diet could interfere catastrophically with healthy tissue development.

Also, because some fatty acids are known to be important immune-system precursors, novel dietary fatty acids could weaken the immune responses just when they are most needed to cope with environmental stresses during key stages of development.

The authors are clear that further testing is required on herbivorous insects and on the consumers of these insects, and that the next step in the risk assessment should involve the feeding of actual GM plants in the laboratory and in the field.

One Swiss senior scientist goes further: "Mandatory extensive testing should be carried out with the actual GM plant, not only on pest herbivores, but also on beneficial insects, butterflies, pest predators, parasites, bees, and pollinators. Concerned scientists like myself have been calling for such testing for decades."


Even in its most elementary form, the experiment rings an environmental alarm bell for novel fatty acid GM crops. Camelina has lots of wild and cultivated relatives through which to spread genetic pollution, novel fatty acids, and knock-on damage to beneficial insects plus all the birds and small mammals which feed on them.

For the farmer, wiping out a pest weakened by the novel oil along with its natural predators will create a gap which could be filled by a pest strengthened by the oil.

The real proof of how alarming the results of this experiment are can probably by measured by the misinformation flowing from the mouths of the pro-GM lobby when the bad news broke. Take heed ...

Don't swallow the line that cabbage whites are pests so that harming them is a benefit (they're part of a much bigger ecosystem).

Don't believe anyone who tells you fish oil in a plant is not unnatural because the same oil is found in moss (no self-respecting cabbage white would eat moss). Or that that fish oil in an oil-seed plant can't be harmful to cabbage whites because they don't eat the seeds (they do). Or that it can't be harmful because clever GM means there's no fish oil in the leaves (no evidence for this has been produced for this, and it may only be true under certain circumstances).

Indeed, Rothamsted seems less confident on the latter point than the pro-GM crowd trying to 'prove' the safety of its novel crop. The Rothamsted scientists have discussed collaborative projects to address the questions of harm to wild-life raised by the Canadians.

Sad that it took scientists on another continent to push the Brits into action.

  • Stefanie M. Hixson, et al., 2016, Long-Chain Omega-3 Polyunsaturated Fatty Acids Have Developmental Effects on the Crop Pest, the Cabbage White Butterfly Pieris rapae, PLOS ONE 24.03.16
  • Nutritionally-enhanced GM crops? Too bad about the deformed butterflies, GM Watch 18.04.16
  • Mark Lynas and Rothamsted make false claims to defend GMOs against deformed butterfly findings, GM Watch 3.05.16

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