A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates

  title={A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates},
  author={Michelle A. Marvier and Chanel McCreedy and James Regetz and Peter Kareiva},
  pages={1475 - 1477}
Although scores of experiments have examined the ecological consequences of transgenic Bacillus thuringiensis (Bt) crops, debates continue regarding the nontarget impacts of this technology. Quantitative reviews of existing studies are crucial for better gauging risks and improving future risk assessments. To encourage evidence-based risk analyses, we constructed a searchable database for nontarget effects of Bt crops. A meta-analysis of 42 field experiments indicates that nontarget… 
Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis
No uniform effects of Bt cotton, maize and potato on the functional guilds of non-target arthropods are found and the importance of using controls not only to isolate the effects of a Bt crop per se but also to reflect the replacement of existing agricultural practices is highlighted.
Database of non-target invertebrates recorded in field experiments of genetically engineered Bt maize and corresponding non-Bt maize
Objectives To assess potential non-target effects of genetically engineered/modified (GM) maize that produces insecticidal proteins from Bacillus thuringiensis (Bt), numerous field experiments have
Does the growing of Bt maize change abundance or ecological function of non-target animals compared to the growing of non-GM maize? A systematic review
The effects of Bt maize on the community of non-target invertebrates inhabiting maize fields were small and mostly neutral, especially when compared with the effects of broad-spectrum pyrethroid insecticide treatments.
Impacts of Bt crops on non-target invertebrates and insecticide use patterns
The efficacy of Bt maize and cotton against major pest species has been associated with an estimated 136.6million kg global reduction in insecticide active ingredient used between 1996 and 2006 (29.9% reduction).
Selection of Nontarget Arthropod Taxa for Field Research on Transgenic Insecticidal Crops: Using Empirical Data and Statistical Power
Analysis of control data from several nontarget field trials using repeated-measures designs suggests that while detection of small effects may require considerable increases in replication, there are taxa from different ecological roles that are sampled effectively using standard methods.
The effect of Bt crops on soil invertebrates: a systematic review and quantitative meta-analysis.
Review and analyze a selection of studies on Protista, nematodes, Collembola, mites, enchytraeids, and earthworms systematically to empower the evidence for asking the question whether population abundances and biomasses of soil invertebrates are changed by Bt crops compared to conventional crops.
Assessment of risk of insect-resistant transgenic crops to nontarget arthropods
An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods posed by insect-resistant, genetically modified (IRGM) crops to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops.
Review: biosafety assessment of Bt rice and other Bt crops using spiders as example for non-target arthropods in China
This review summarizes and analyzes evidences for non-target effects of Bt rice on spiders, major predators in rice fields, and raises questions and provides recommendations for promising further research.
Application of Meta-analysis in the Safety Assessments of Transgenic Crops
Here the concept and procedure of meta-analysis and its application in the safety assessment of transgenic crops are introduced and the limitation ofMeta-analysis is recognized, which may promote a wide application ofmeta-analysis in the future.
Effects of GM Crops on Non-target Organisms
A body of evidence and the quantitative and qualitative syntheses of the data through meta-analysis and other compilations generally indicate a lack of direct impacts of Bt crops on non-target macro-invertebrates, and data clearly show that BT crops are much safer to non- target organisms than the alternative use of traditional insecticides.


Environmental fate and effects of Bacillus thuringiensis (Bt) proteins from transgenic crops: a review.
Assessment of the nontarget effects of Bt protein toxins indicates that there is a low level of hazard to most groups of nontarget organisms, although some investigations are of limited ecological relevance.
Transgenic crops expressing Bacillus thuringiensis toxins and biological control
Because Bt-transgenic varieties can lead to substantial reductions in insecticide use in some crops, they can contribute to integrated pest management systems with a strong biological control component.
In many countries, government regulations require environmental risk as- sessment prior to commercial sale and widespread planting of transgenic crops. Here I evaluate the design and statistical
The impact of transgenic plants on natural enemies: a critical review of laboratory studies
These involve various parameters, organisms, test methods, and significance levels, but collectively they indicate that the use of genetically modified crops may result in negative effects on the natural enemies of crop pests.
Assessing environmental risks of transgenic plants.
This review focuses on changes in the assessment of risks associated with non-target species and biodiversity, gene flow, and the evolution of resistance in the environmental risk assessment process since 1990.
GEOs should be evaluated and used within the context of a scientifically based regulatory policy that encourages innovation without compromising sound environmental management, and science-based regulation should subject all transgenic organisms to a similar risk assessment framework.
The real and perceived risks of genetically modified organisms
The debate about the potential risks of genetically modified organisms has lasted for almost three decades without any final conclusion in sight. Why is it that the public remains critical of this
Attitudes to biotechnology: Estimating the opinions of a better-informed public
The findings demonstrate that scientific knowledge does appear to have an important role in determining individual and group attitudes to genetic science, and find no support for a simple ‘deficit model’ of public understanding.
Trust, emotion, sex, politics, and science: surveying the risk-assessment battlefield.
  • P. Slovic
  • Education
    Risk analysis : an official publication of the Society for Risk Analysis
  • 1999
It is argued that danger is real, but risk is socially constructed and there is a need for a new approach to risk management that focuses upon introducing more public participation into both risk assessment and risk decision making in order to make the decision process more democratic, improve the relevance and quality of technical analysis, and increase the legitimacy and public acceptance of the resulting decisions.
The ecological risks and benefits of genetically engineered plants.
A review of existing scientific literature reveals that key experiments on both the environmental risks and benefits are lacking, and existing studies emphasize that these can vary spatially, temporally, and according to the trait and cultivar modified.