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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: The end of a myth – Bt(Cry1Ab)maize does not harm green lacewings

Authors
item Romeis, J -
item Meissle, M -
item NARANJO, STEVEN
item Li, Y -
item Bigler, F -

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 22, 2014
Publication Date: August 12, 2014
Citation: Romeis, J., Meissle, M., Naranjo, S.E., Li, Y., Bigler, F. 2014. The end of a myth – Bt(Cry1Ab)maize does not harm green lacewings. Frontiers in Plant Science. 5:391(doi:10.3389/fpls.2014.00391).

Interpretive Summary: Transgenic Bt maize has been commercially grown in the USA since 1996, was introduced into Europe beginning in 1998 and is currently cultivated in 17 countries. One of the major concerns surrounding GM crop cultivation in general is the effect of these crops on non-target organisms and biodiversity. One insect that has come to represent the debate is the green lacewing, a common predator found in many field crops that contributes to biological control of many pest species. In the late 1990’s, several studies were published that suggested that the Bt proteins found in Bt maize could be harmful to lacewing larvae. However, since these early reports many follow-up studies have failed to repeat these results. This study uses an objective framework to examine the data available to date. The Bt proteins can be found in food ingested by lacewings and it is biologically active. However, this exposure to the Bt proteins does not affect any biological aspects of the insect nor has the cultivation of Bt maize had any affect on the abundance or the biological control function of this important predator in the field. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies. These results should be useful to regulatory authorities involved in GM crop approval and to the general public concerned with the environmental impacts of GM crops.

Technical Abstract: A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize crops or by the expressed Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies.

Last Modified: 9/29/2014
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