A comprehensive review authored by scientists from Switzerland and the
United States summarized the existing literature on Bt crops from laboratory
and field-based studies. The authors, Jörg Romeis, Steven E. Naranjo,
Michael Meissle, and Anthony M. Shelton highlight the contribution of Bt
crops to conservation biological control.
The paper published in the journal Biological Control reports that Bt crops
have been grown on more than 1 billion acres over the last 20+ years, and on
100 million hectares in 2017 alone. A major concern related to this
technology is that the proteins could harm non-target organisms,
specifically those that provide important ecosystem services such as
biological control. However, studies have proven that proteins from Bt crops
did not harm natural enemies. Furthermore, Bt crops support the conservation
of natural enemies and contribute to more effective biological control of
both target and secondary pests and lead to a reduction in insecticide use.
The paper concludes that the efficacy of Bt crops in controlling important
target pests has been very high. The large-scale adoption of Bt crops in
some parts of the world has led to area-wide suppressions of target pest
populations that benefited both the farmers that adopted the technology and
those that did not.