When compared to cultivating traditional corn, genetically modified Bt corn has little influence on nontarget insects and other creatures, according to the largest and best quality data analysis yet undertaken. A USDA Agricultural Research Service scientist and his Swiss coworkers reported this analysis today in Environmental Evidence.
Corn that has been genetically intended to generate proteins from the Bacillus thuringiensis bacteria to control corn borers, maize rootworms, and other significant corn pests is known as Bt corn. Bt corn was initially approved in 1996, and critics have claimed that it can also kill beneficial insects and other non-targeted organisms.
One of the problems with assessing the potential for Bt corn to harm nontarget organisms has been that each review was confined in area, habitat, or size. The paper’s three authors compensated for these flaws by meticulously compiling data from studies found in 12 bibliographic databases, 17 specialist websites, and the reference sections of 78 review papers that all satisfied the highest research quality requirements.
We gathered together hundreds of individual studies published between 1997 to 2020 that have looked at whether growing Bt corn changed the environmental abundance of non-target animals such as arthropods, earthworms and nematodes, especially as compared to growing non-genetically modified corn accompanied by the pesticide necessary to control major pests.”
Steve Naranjo, Study Author and Entomologist, Agricultural Research Service, USDA
Naranjo was also the director of the U.S. Arid Land Agricultural Research Center in Maricopa, Arizona.
This vast accumulation of data demonstrated that Bt corn had no harmful effects on most invertebrate taxa, including ladybeetles, flower bugs, and lacewings, according to Naranjo and entomologists Joerg Romeis and Michael Meissle of Agroscope, ARS’ Swiss counterpart. With Bt corn, populations of Braconidae insects, parasitoid wasps that prey on corn borers, were decreased.
The researchers also looked at whether biotechnology companies’ authorship or financial assistance influenced the results of particular studies.
It might be a bit surprising but according to the analysis, when any negative effects by Bt corn on nontarget organisms were found in the data, they were attributed more often in studies with private sector support than when no backing by biotech companies was declared,”
Michael Meissle, Entomologist, Agroscope
“But after all the number crunching was done, what we found was that, overall, Bt corn just does not have negative impacts on non-target organisms,” added Naranjo.
Stakeholders, researchers not involved in the meta-analysis project, and even members of the paper’s review panel outlined and vetted the quality standards for which research would be included in the meta-analysis and which would be cut, with none of them knowing whether any study’s data showed a significant negative effect on non-target organisms or not.
The outcome is the largest pool of high-quality data ever evaluated for this purpose, with 7279 individual invertebrate records from 233 investigations in 120 articles, with 75% of them coming from peer-reviewed journals. BMC Research Notes has also published the whole data set.
In conclusion, this comprehensive meta-analysis essentially confirmed the findings of earlier individual research. According to the researchers, Bt corn is a highly selective pest control method with little negative repercussions for non-target invertebrates, particularly when compared to using broad-spectrum pesticides to manage Bt-targeted pests.
Meissle, M., et al. (2022) Database of non-target invertebrates recorded in field experiments of genetically engineered Bt maize and corresponding non-Bt maize. BMC Research Notes. doi.org/10.1186/s13104-022-06021-3.