GE - IACR GM OSR research - answers to the wrong questions?
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- Subject: GE - IACR GM OSR research - answers to the wrong questions?
- From: genetics <email@example.com>
- Date: Mon, 06 Sep 1999 19:50:34 +0100
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>From: "NLP Wessex" <email@example.com>
>Subject: IACR GM OSR research - answers to the wrong questions?
>Date: Sun, 5 Sep 1999 22:57:02 +0100
>X-Mailer: Microsoft Outlook Express 4.72.3110.1
>The UK's IACR already has a track record of only highlighting part of the
>story when releasing 'postive' biotech news stories (see
>Whether or not this proves to be the case here remains to be seen, but it is
>unlikely that such a study can have had the opportunity to look at the full
>range of environmental impacts from Bt rape. This report only refers to the
>impact on one non-target species. What about the remainder, and the impact
>the Bt toxin on fertility building soil micro-organisms when GM crop
>residues are ploughed under in preparation for the next crop?
>Other work has already indicated possible deleterious effects on soil
>(e.g Fem Microbiology Ecology,1999, Vol.28, No.3, pp.261-272,
>and Soil Biology and Biochemistry 30: 463-70, 1998, )
>arising from transgenic plant residues.
>It is also interesting that the 'positive' comparison being made here is in
>relation to existing farming systems reliant on insecticides. This is at a
>time when increasingly farmers are in any case reducing their dependence on
>insecticides by developing systems of integrated crop management. In some
>cases this allows them to dispense with insecticides altogether. As a
>symptom of this a report on the front page of Farming News 3rd September
>1999 clearly identifies the diminishing market for agro-chemicals in the UK,
>well in advance of any commercial introduction of GM crops.
>To a greater or lesser degree, therefore, the IACR study may in effect
>a "so what" conclusion, although in practice it is unlikely that this aspect
>will have been reflected upon by the researchers.
>Finally it is well know that target pest species for Bt crops rapidly
>develop resistance to its toxicity and therefore the use of such technology
>becomes ineffective in a short period of time (for more information on this
>In the US farmers are already being prohibited from planting Bt vareties on
>up to 40% or more of
>their crop acreage because of this problem. This is despite the fact that
>the technology has only recently been introduced.
>By definition an approach which has declining efficacy is not sustainable.
>NATURAL LAW PARTY WESSEX
>Footnote: contrary to the report below IACR stands for 'Institute of Arable
>Crops Research' (definately NOT Integrated Approach to Crop Research!)
>Rape Better for Environment, Says IACR Research
>Some crops which have been genetically modified (GM) to produce pesticides
>may have an "environmental advantage" over sprays, because they do not harm
>beneficial insects, according to UK researchers. The team at the Integrated
>Approach to Crop Research (IACR), Hertfordshire, showed that GM oilseed rape
>which produces the Bacillus thuringiensis (Bt) toxin does not harm a wasp
>which kills a pest moth. Nor did the crop prevent the parasitic wasp finding
>the moth's larvae.
>The scientists Tanja Schuler, Roel Potting, Ian Denholm and Guy Poppy
>conclude that the GM rape, which allows the wasps to continue killing the
>moths, may therefore be better for the environment than insecticide sprays,
>which kill both the moths and the wasps.
>In May, a team at Cornell University showed that pollen from Bt maize can
>kill the larvae of monarch butterflies, which raised concern about the
>impact of such GM crops. The IACR researchers believe their work shows that
>the behaviour of non-target insects can be as important as toxicity in
>determining the impact of GM plants. The study is published in Nature.
>The laboratory-based experiment involved GM oilseed rape, the diamondback
>moth (Plutella xylostella) that damages the crop, and the parasitic wasp
>(Cotesia plutellae), which kills the moths' caterpillars by laying its eggs
>in them. Adult wasps were allowed to lay their eggs in the larvae of highly
>Bt-resistant moths, which had been fed on the Bt rape. But the presence of
>the toxins in the moth larvae made no difference to the survival rates of
>the wasps, as larvae or adults. "
>The parasitic wasps find the host moths via a chemical signal released by
>the plant when its leaves are damaged by the moth. To find if the wasps had
>a preference for Bt rape and non-modified rape, the plants were placed in a
>wind tunnel. No distinction was found in the level of feeding damage between
>the two types of plant. The researchers say that: "The continued ability of
>the wasps to locate and lay their eggs in Bt-resistant larvae on transgenic
>crops might even help to constrain the spread of genes for Bt resistance in
>the moths. "Our results highlight the need to consider behavioural as well
>as toxicological aspects when looking at possible side effects of transgenic
>crops on non-target organisms."
>Guy Poppy told the BBC: "What we're saying is that it is important to judge
>the impact of a transgenic plant against a conventional insecticide. What
>our research shows is that the transgenic plant has much less impact on
>these non-target organisms than the alternative of using a broad-spectrum
>The UK Government's official wildlife advisory body English Nature, which
>has raised concerns about GM technology, welcomed the research. "I think it
>is a very interested piece of research because it gives us pointers to the
>sorts of things that we need to take outside from these laboratory trials
>into the field trials," says Chief Executive Keith Duff. "It is only by
>looking in the field that we will really see what the effect of these
>modifications is on wildlife."
>The paper, Parasitoid behaviour and Bt plants, Tanja H. Schuler, Roel P. J.
>Potting, Ian Denholm and Guy M. Poppy appears in Nature 400, 825 829.
>See Hot Topic: Bt plants: resistance and other issues.
>See also Tanja Shuler’s research as discussed in Gene Flow and Agriculture:
>Relevance for Transgenic Crops.
>Contact: Guy M. Poppy, IACR-Rothamsted, Rothamsted, Harpenden,
>Hertfordshire, AL5 2JQ, UK
>Tel: + 44 (0) 1582 763 133
>Fax: + 44 (0) 1583 461 366