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EFSA Admits Bt Maize Threat to Butterflies, Gives Green Light Regardless

Immediate release (13 Dec 2011)

Calls to: Pete Riley 07903 341 065

The European Food Safety Authority GMO Panel’s new opinion on Pioneer Hybrid/Mycogen Seed’s insect resistance GM maize (known as 1507) acknowledges the crop puts non-target species at risk, including iconic butterflies, but disregards both these risks and big gaps in the applicant’s data in recommending the crop for EU cultivation. [1]

In contrast to a 2005 opinion giving 1507 the all clear, the EFSA GMO Panel now says, “Highly sensitive non-target Lepidoptera populations might be at risk,” if they ingest pollen from the GM maize that falls on plants used by their larvae for food.

Many common and iconic butterflies could be harmed because their food plants are frequently found in and around arable fields, so their larva may consume 1507 pollen on these plants. The “at risk” list includes the Painted Lady, Peacock, Small Tortoiseshell, Common Blue and Orange Tip.

However the Panel nevertheless supports the approval of 1507 maize, saying the potential harmful effects can be mitigated.

GM Freeze today published a critique [2] of the new EFSA opinion that highlights a number of scientific weaknesses in the case put by the Panel. These include:

  • Insufficient toxicity data for all species of moths and butterflies likely to be exposed to the GM toxin, known as Cry1F, from 1507 maize.
  • Almost complete lack of data on the sub-lethal impacts of Cry1F on non-target moths and butterflies.
  • Confusion over the precise amounts of Cry1F toxin in 1507 pollen.
  • Lack of data to support claims that mitigation measures will be effective in protecting sensitive species.
  • Flawed assumptions regarding how far maize pollen travels.
  • Failure to take into account exposure from three other GM maize applications currently before the EU that also include the 1507 GM traits to produce Cry1F toxin.

GM Freeze is also concerned that the Panel plays down the risk that the targeted insect pest may develop resistance to 1507 maize, a substantial and growing problem elsewhere. [3]

Farmland moths and butterflies are already under pressure from habitat destruction and the use of agrochemicals in intensive farming systems employed across the EU. Maize is one of the most intensively grown crops, often in monocultures on the same land in successive years.

The case of 1507 maize is an excellent example of how scientific understanding develops over time. In the six years between EFSA’s two opinions evidence of harm emerged where the agency originally said there was no risk, nevermind harm. Genetics is an imperfectly understood discipline, which is why we must take a precautionary approach to all GM food and crops – what we do not know now may emerge as problems later.

Commenting Pete Riley of GM Freeze said:

It is extraordinary that EFSA wants to give this maize the green light for commercial cultivation when it has identified a problem and admits there is insufficient data to carry out a full risk assessment.

This is a clear case for the application of the precautionary approach and to delay making a decision until sufficient data is available. We should not treat our countryside as a private laboratory.

Pushing mitigation measures that may not be adopted by farmers when it isn’t even clear if such measures will work is also unacceptable.

EFSA’s reputation as the organisation that says ‘yes’ to GM crops whatever the evidence comes from decisions like this. EU Members States must continue to challenge EFSA on this approach to GM crops. EFSA constantly compares GM systems with outdated chemical intensive farming systems instead of supporting more integrated pest management systems used in agroecological approaches.



[1] EFSA GMO Panel, 2011. “Scientific Opinion updating the evaluation of the environmental risk assessment and risk management recommendations on insect resistant genetically modified maize 1507 for cultivation”. EFSA Journal 9:2429

[2] GM Freeze, In Two Minds: EFSA GMO Panel concedes Bt crop is a risk to non-target moths and butterflies, but hangs hopes on unproven mitigation

[3] GM Freeze, Insect Resistance to Bt Toxins in GM Insect Resistant Crops