Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Sustainable Pest Management Strategies for Arid-land Crops

Location: Pest Management and Biocontrol Research

Title: Errors in logic and statistics plague a meta-analysis

Authors
item Shelton, Anthony -
item Naranjo, Steven
item Romeis, Joerg -
item Hellmich, Richard

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 25, 2012
Publication Date: October 1, 2012
Citation: Shelton, A., Naranjo, S.E., Romeis, J., Hellmich II, R.L. 2012. Errors in logic and statistics plague a meta-analysis. Environmental Entomology. 41:1047-1049.

Interpretive Summary: The non-target effects of transgenic insecticidal crops has been a topic of debate for over a decade and many laboratory and field studies have addressed the issue in numerous countries. In 2009 Lovei et al. (Transgenic Insecticidal Crops and Natural Enemies: A Detailed Review of Laboratory Studies) published an analysis of the extant laboratory data bearing on the issue of non-target effects focused on natural enemies. A series of letters to the editor were exchanged on that original paper. Recently two of the original authors (Andow and Lovei) drafted another letter that corrected a statistical error in their original analysis and further debated points that have already been discussed in the many letters. This brief letter re-emphasizes two points which Andow and Lovei continue to ignore, the effects of prey/host quality in tritrophic exposure studies and the ecological context of their results. Overall, nearly half of all the data analyzed by Lovei et al. 2009 could not separate the effects of Bt proteins from the effects of prey/host quality and thus do not provide a robust test of Bt toxicity. We think that environmental risk assessments of transgenic insect-resistant crops are critical, and that proper methods and logic will be required to assess extant studies.

Technical Abstract: The non-target effects of transgenic insecticidal crops has been a topic of debate for over a decade and many laboratory and field studies have addressed the issue in numerous countries. In 2009 Lovei et al. (Transgenic Insecticidal Crops and Natural Enemies: A Detailed Review of Laboratory Studies) published an analysis of the extant laboratory data bearing on the issue of non-target effects focused on natural enemies. A series of letters to the editor were exchanged on that original paper. Recently two of the original authors (Andow and Lovei) drafted another letter that corrected a statistical error in their original analysis and further debated points that have already been discussed in the many letters. This brief letter re-emphasizes two points which Andow and Lovei continue to ignore, the effects of prey/host quality in tritrophic exposure studies and the ecological context of their results. Overall, nearly half of all the data analyzed by Lovei et al. 2009 could not separate the effects of Bt proteins from the effects of prey/host quality and thus do not provide a robust test of Bt toxicity. We think that environmental risk assessments of transgenic insect-resistant crops are critical, and that proper methods and logic will be required to assess extant studies.

Last Modified: 10/23/2014