The cultivation of Bt corn producing Cry1Ac toxins does not adversely affect non-target arthropods.

Yanyan Guo,Xuehui Dong,Wangpeng Shi,Yang Ge,Guillaume Tetreau,Xiaowen Chen,Yanjie Feng,Nicolas Desneux

doi:10.1371/journal.pone.0114228

Yanyan Guo, Xuehui Dong + Show 6 more

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https://doi.org/10.1371/journal.pone.0114228

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Abstract

Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt) provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée), and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs) is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The “sampling dates” had a significant effect on these indices, but no clear tendencies related to “Bt corn” or “sampling dates X corn variety” interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs.

Highlights

Modified (GM) crops have been planted for two decades since the first commercialized Genetically modified (GM) crop was released in 1994 [1]
The development of GM corn producing Cry toxins significantly reduced the use of insecticides in the environment [8], and may alleviate the risks of non-target arthropods (NTAs) exposure to insecticides
With the large scale planting of transgenic Bacillus thuringiensis (Bt) corn, an increasing number of scientists devoted to monitoring the environmental impact of Bt corn on NTAs [58,59,60]

Summary

Introduction

Modified (GM) crops have been planted for two decades since the first commercialized GM crop was released in 1994 [1]. In 2013, 18 million farmers benefited from planting GM crops in more than 30 countries worldwide [2]. The most famous and widespread GM crops are those producing Bacillus thuringiensis (Bt) toxins, which represent the most environmentally-safe alternative to chemical insecticides for pest control in agriculture [3,4]. In China, largely owing to the cultivation of Bt cotton against cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), the use of insecticides decreased greatly [5,6,7]. The cultivation of Bt corn can even decrease insecticide applications in agricultural fields by more than 50% [8]

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