Study shows GMO-associated toxins shown are harmful to an important pollinator
Cry toxins are the insecticidal toxins in GM Bt crops. Glyphosate herbicide is used on at least 85% of all GM crops grown worldwide.
Stingless bees are important pollinators for various crops in Brazil, where this study was conducted.
Glyphosate is lethal and Cry toxins alter the development of the stingless bee Melipona quadrifasciata
Vanessa Eler Seide, Rodrigo Cupertino Bernardes, Eliseu Jose Guedes Pereira, Maria Augusta Pereira Lima
Environmental Pollution 243 (2018) 1854e1860
Full text available from:
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.