Transgenic Bt maize does not affect the soil ant community

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.