Departamento de Biologia Animal, Universidade Federal de Viçosa, MG, 36570-900, Brazil.
Departamento de Entomologia, Universidade Federal de Viçosa, MG, 36570-900, Brazil.
Environ Pollut. 2018 Dec;243(Pt B):1854-1860. doi: 10.1016/j.envpol.2018.10.020. Epub 2018 Oct 3.
Brazil is the second largest producer of genetically modified plants in the world. This agricultural practice exposes native pollinators to contact and ingestion of Bacillus thuringiensis proteins (e.g. Cry toxins) from transgenic plants. Furthermore, native bees are also exposed to various herbicides applied to crops, including glyphosate. Little is known about the possible effects of glyphosate and Cry proteins on stingless bees, especially regarding exposure at an immature stage. Here, we show for the first time that glyphosate is lethal, and that Cry toxins (Cry1F, Cry2Aa) alter the development of the stingless bee Melipona quadrifasciata upon contamination of larval food. Glyphosate was very toxic to the bee larvae, killing all of them within only a few days of exposure. Bees treated with Cry2Aa proteins had a higher survival rate and were delayed in their development, compared to the negative controls. Those treated with the Cry1F protein also suffered delays in their development, compared to the negative controls. In conclusion, the proteins Cry1F, Cry2Aa, and the herbicide glyphosate were highly toxic to the stingless bee M. quadrifasciata, causing lethal or sublethal effects which can severely impair colony growth and viability, and reduce pollination ability.
巴西是世界上第二大转基因植物生产国。这种农业实践使本地传粉媒介接触并摄入来自转基因植物的苏云金芽孢杆菌蛋白（如 Cry 毒素）。此外，本地蜜蜂还会接触到各种应用于作物的除草剂，包括草甘膦。关于草甘膦和 Cry 蛋白对无刺蜜蜂的可能影响，特别是在不成熟阶段的暴露，知之甚少。在这里，我们首次表明草甘膦是致命的，Cry 毒素（Cry1F、Cry2Aa）会改变无刺蜜蜂 Melipona quadrifasciata 的幼虫食物被污染后的发育过程。草甘膦对蜜蜂幼虫非常有毒，仅在接触后的几天内就杀死了所有幼虫。与阴性对照相比，用 Cry2Aa 蛋白处理的蜜蜂存活率更高，发育延迟。用 Cry1F 蛋白处理的蜜蜂的发育也比阴性对照延迟。总之，Cry1F、Cry2Aa 蛋白和除草剂草甘膦对无刺蜜蜂 M. quadrifasciata 具有高度毒性，导致致死或亚致死效应，严重损害了群体生长和活力，并降低了授粉能力。
