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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: Effects of bt crops on arthropod natual enemies: a global synthesis

Author
item Naranjo, Steven

Submitted to: International Symposium on Biological Control of Arthropods
Publication Type: Proceedings
Publication Acceptance Date: March 1, 2013
Publication Date: N/A

Interpretive Summary: The global adoption of transgenic crops producing the insecticidal proteins from Bacillus thuringiensis Berliner (Bacillaceae), (Bt) continues to grow with 66 M hectares of Bt crops grown in a total of 25 countries in 2011 (James 2011). Unintended environmental effects from the technology continue to be of concern, with one of the key issues being effects on valued non-target organisms. A large number of non-target studies have been completed over the past 15-20 years in support of risk assessment in Bt crops. In late 2008 Naranjo (2009) cataloged over 360 original research articles that have studied the effects of Bt crops on non-target invertebrates. These include studies of 9 crop plants and dozens of Bt proteins in a total of 15 countries. Since 2008 the pace of research in this area has diminished only slightly, with a total of over 520 studies as of mid 2012, and the number of participating countries has expanded. A number of reviews and meta-analyses have been conducted on portions of this literature in an attempt to summarize and synthesize general and specific patterns (e.g. Romeis et al. 2006, Marvier et al. 2007, Wolfenbarger et al. 2009, Naranjo 2009). In general, these summaries and analyses have demonstrated that Bt crops havenegligible or no effect on non-target arthropod abundance in the field or on various measures of their biology in the laboratory. However, many additional studies have been published since the latest reviews and synthetic studies were completed. Here I re-assess the world literature on arthropod natural enemies and quantify non-target effects of Bt crops via meta-analyses of both laboratory and field studies. The primary question is: do we now have enough data to conclusively determine the effects of current Bt crops on non-target arthropod natural enemies?

Technical Abstract: The global adoption of transgenic crops producing the insecticidal proteins from Bacillus thuringiensis Berliner (Bacillaceae), (Bt) continues to grow with 66 M hectares of Bt crops grown in a total of 25 countries in 2011 (James 2011). Unintended environmental effects from the technology continue to be of concern, with one of the key issues being effects on valued non-target organisms. A large number of non-target studies have been completed over the past 15-20 years in support of risk assessment in Bt crops. In late 2008 Naranjo (2009) cataloged over 360 original research articles that have studied the effects of Bt crops on non-target invertebrates. These include studies of 9 crop plants and dozens of Bt proteins in a total of 15 countries. Since 2008 the pace of research in this area has diminished only slightly, with a total of over 520 studies as of mid 2012, and the number of participating countries has expanded. A number of reviews and meta-analyses have been conducted on portions of this literature in an attempt to summarize and synthesize general and specific patterns (e.g. Romeis et al. 2006, Marvier et al. 2007, Wolfenbarger et al. 2009, Naranjo 2009). In general, these summaries and analyses have demonstrated that Bt crops havenegligible or no effect on non-target arthropod abundance in the field or on various measures of their biology in the laboratory. However, many additional studies have been published since the latest reviews and synthetic studies were completed. Here I re-assess the world literature on arthropod natural enemies and quantify non-target effects of Bt crops via meta-analyses of both laboratory and field studies. The primary question is: do we now have enough data to conclusively determine the effects of current Bt crops on non-target arthropod natural enemies?

Last Modified: 9/21/2014
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