Transgenic Bt maize does not affect the soil ant community

Valéria Cristina Barbosa De Assis,Cidália Gabriela Santos Marinho,Jacques Hubert Charles Delabie,Simone Martins Mendes,Pedro Guedes Chagas,Marcos Antônio Matiello Fadini

doi:10.1590/s0100-204x2018000200003

Valéria Cristina Barbosa De Assis, Cidália Gabriela Santos Marinho + Show 4 more

Open Access

https://doi.org/10.1590/s0100-204x2018000200003

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Abstract

Abstract: The objective of this work was to survey soil ants in Bt and non-Bt maize (Zea mays) crops, and to compare their effect on the soil ant community. Nine pitfall traps, 10 m apart, were installed in a central area (900 m2) of each of the following treatments (2,500 m2): conventional maize; maize modified with the Cry1F, Cry1Ab, and Vip3A proteins; and a native vegetation area. Fortnightly collections were conducted during four periods (complete producing cycles) of the crop, from 2011 to 2013. The number of ant species varied from 25 in Bt maize (Vip 3A) to 58 in Bt maize (Cry 1F). The treatment with conventional maize showed the highest Shannon-Wiener diversity index (H’ = 2.60). Jaccard’s index showed that there is dissimilarity between the cultivated maize areas and the native vegetation area in most treatments, and that Bt and non-Bt maize show similarity in their soil ant assemblages. The cultivation of Bt maize does not affect the soil ant community. The subfamily Myrmicinae shows the highest number of species in all the collection periods, with 57, 41, 47, and 50 species in the first, second, third, and fourth periods, respectively. The genus Pheidole, belonging to this subfamily, shows the greatest number of species.

Highlights

Maize (Zea mays L.) is intensely cultivated throughout the world due to its importance for animal feed, especially poultry and swine, and for human food
In 2015, maize was cultivated in Brazil in more than 15 million hectares (IBGE, 2016), from which 86.8% was maize genetically modified with Bacillus thuringiensis (Berliner, 1915) gene (Attie, 2016)
Areas of conventional maize and of maize genetically modified with B. thuringiensis (Bt) were used, as they show a history of intensive maize and sorghum cultivation; and an area of native vegetation (NV), characterized as Seasonal Forest Always Green (Costa et al, 2015)

Summary

Introduction

Maize (Zea mays L.) is intensely cultivated throughout the world due to its importance for animal feed, especially poultry and swine, and for human food. As a result of the demand for this grain, larger areas are increasingly subjected to an intensive and competitive agriculture, which causes a lot of phytosanitary problems that should be overcome to obtain quality production. In 2015, maize was cultivated in Brazil in more than 15 million hectares (IBGE, 2016), from which 86.8% was maize genetically modified with Bacillus thuringiensis (Berliner, 1915) gene (Attie, 2016). This technology is used mostly to reduce damages caused by the attack of the fall armyworm [Spodoptera frugiperda 1797)] that is considered the main pest in maize (Cruz et al, 2008)

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