Transgenic pollen harms monarch larvae

Losey, John E.; Rayor, Linda S.; Carter, Maureen E.

doi:10.1038/20338

Cited by 970 publications

(485 citation statements)

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“…Of particular interest are beneficial insects such as pollinators (Picard-Nizou et al, 1995;Arpaia, 1996;Poppy, 1998;Malone et al, 2001) and natural enemies of pests (Hilbeck et al, 1998;Birch et al, 1999;Bell et al, 2001), but the effects on non-target Lepidoptera has also received much attention (Losey et al, 1999;Jesse & Obrycki, 2000;Wraight et al, 2000;Zangerl et al, 2001). The debate on how to conduct these assessments has not yet been settled, but it is commonly accepted that realistic tests should compare conventional methods with the strategy of employing transgenic plants, although this is rarely done as yet.…”

Section: Introductionmentioning

confidence: 99%

Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps

et al. 2005

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The current discussion on the safety of transgenic crops includes their effects on beneficial insects, such as parasitoids and predators of pest insects. One important plant trait to consider in this context is the emission of volatiles in response to herbivory. Natural enemies use the odours that result from these emissions as cues to locate their herbivorous prey and any significant change in these plant-provided signals may disrupt their search efficiency. There is a need for practical and reliable methods to evaluate transgenic crops for this and other important plant traits. Moreover, it is imperative that such evaluations are done in the context of variability for these traits among conventional genotypes of a crop. For maize and the induction of volatile emissions by caterpillar feeding this variability is known and realistic comparisons can therefore be made. Here we used a six-arm olfactometer that permits the simultaneous collection of volatiles emitted by multiple plants and testing of their attractiveness to insects. With this apparatus we measured the induced odour emissions of Bt maize (Bt11, N4640Bt) and its near-isogenic line (N4640) and the attractiveness of these odours to Cotesia marginiventris and Microplitis rufiventris, two important larval parasitoids of common lepidopteran pests. Both parasitoid species were strongly attracted to induced maize odour and neither wasp distinguished between the odours of the transgenic and the isogenic line. Also wasps that had previously experienced one of the odours during a successful oviposition divided their choices equally between the two odours. However, chemical analyses of collected odours revealed significant quantitative differences. The same 11 compounds dominated the blends of both genotypes, but the isogenic line released a larger amount of most of these. These differences may be due to altered resource allocation in the transgenic line, but it had no measurable effect on the wasps' behaviour. All compounds identified here had been previously reported for maize and the differential quantities in which they were released fall well within the range of variability observed for other maize genotypes.

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Section: Introductionmentioning

confidence: 99%

Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps

et al. 2005

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“…The results suggested that pollen from the most widely planted Bt-maize events (MON810 and Bt 11) will have no acute effects on larvae in field settings [62,63] since their pollen expresses 80 times less toxin than Event 176 [63]. The results also suggested that pollen densities used by Losey et al [61] were in excess compared to pollen densities present in maize fields or that the pollen of event Bt 11 used may have been contaminated with non-pollen tissues [64]. Excessive pollen densities of the currently commercialized events (Bt 11 and MON810) would be required to obtain relevant adverse effects on larval developments [62].…”

Section: Effects Of Bt-crops On Butterfliesmentioning

confidence: 87%

“…The case of Bt-maize pollen and the monarch butterfly (Danaus plexippus) caused much public interest and led to a debate over the potential risks and the environmental impact of Bt-maize. Losey et al [61] found that when pollen from a commercial variety of Bt-maize (event Bt 11) was spread on milkweed leaves in the laboratory and fed to monarch butterfly larvae, the larvae consumed significantly less from these leaves compared with leaves dusted with non-transgenic pollen. In addition, after 4 days, almost half of the tested larvae died, which was significantly more than on the leaves with non-transgenic pollen where none of the tested larvae died.…”

Section: Effects Of Bt-crops On Butterfliesmentioning

confidence: 99%

Ecological Impacts of Genetically Modified Crops: Ten Years of Field Research and Commercial Cultivation

Sanvido

Romeis

Bigler

Green Gene Technology

110

102

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“…The publication by Losey et al (1999) showing that Monarch larvae are sensitive to Bt maize pollen, which can be regarded as a typical Tier 1 study, was at the origin of a major controversy that could probably have been avoided. That Monarch larvae could be harmed by Bt maize pollen was not surprising, since Cry1Ab is toxic to many Lepidoptera, but in the absence in 1999 of exposure data from the field, it was impossible at the time to determine the actual risk to the populations of Monarchs.…”

Section: Box 2 the Monarch Butterfly Controversy Seen In Retrospectmentioning

confidence: 99%

Fitness and beyond: Preparing for the arrival of GM crops with ecologically important novel characters

Wilkinson

Tepfer

2009

Environ. Biosafety Res.

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The seemingly inexorable expansion of global human population size, significant increases in the use of biofuel crops and the growing pressures of multifunctional land-use have intensified the need to improve crop productivity. The widespread cultivation of high-yielding genetically modified (GM) crops could help to address these problems, although in doing so, steps must also be taken to ensure that any gene flow from these crops to wild or weedy recipients does not cause significant ecological harm. It is partly for this reason that new GM cultivars are invariably subjected to strict regulatory evaluation in order to assess the risks that each may pose to the environment. Regulatory bodies vary in their approach to decision-making, although all require access to large quantities of detailed information. Such an exhaustive case-by-case approach has been made tractable by the comparative simplicity of the portfolio of GM crops currently on the market, with four crops and two classes of traits accounting for almost all of the area under cultivation of GM crops. This simplified situation will change shortly, and will seriously complicate and potentially slow the evaluation process. Nowhere will the increased diversity of GM crops cause more difficulty to regulators than in those cases where there is a need to assess whether the transgene(s) will enhance fitness in a non-transgenic relative and thereafter cause ecological harm. Current practice to test this risk hypothesis focuses on attempting to detect increased fitness in the recipient. In this paper we explore the merits and shortcomings of this strategy, and investigate the scope for developing new approaches to streamline decision-making processes for transgenes that could cause unwanted ecological change.Keywords: environmental risk assessment / fitness / fitness parameters / GM crops / invasiveness / weediness THE CONTEXT OF ENVIRONMENTAL RISK ASSESSMENTThroughout the world, wherever transgenic crops are grown outside the confines of the laboratory, there is a regulatory system for governing and monitoring the conditions under which experimental field trials and/or commercial cultivation is sanctioned. There is considerable variation between individual countries in the legislative frameworks that dictate how decisions to permit, delay or halt the release of a particular transgenic event are made (Capalbo et al., 2003;Cardwell and Kerr, 2008;Guehlstorf and Hallstrom, 2005; Jepson et al., 2005;Kalaitzandonakes et al., 2007;Nasiruddin and Nasim, 2007;Ramjoue, 2007;Salleh, 2006;Zafar, 2007). Nevertheless, there appears to be a growing harmonization of the underlying process that governs decision-making, * Corresponding author: jjw@aber.ac.uk with all systems adopting a case-by-case approach in which large bodies of evidence are first presented and then evaluated in a reiterative fashion.The documents made in support of individual submissions are usually rather weighty and data-rich; they invariably include substantial information relating to the biology and agr...

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Transgenic pollen harms monarch larvae

Cited by 970 publications

References 1 publication

Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps

Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps

Ecological Impacts of Genetically Modified Crops: Ten Years of Field Research and Commercial Cultivation

Fitness and beyond: Preparing for the arrival of GM crops with ecologically important novel characters

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