Brazil is the second largest producer of genetically modified (GM) 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.

Various bee species are suffering large population declines. Stingless bees are important wild pollinators which have a life history which makes them more susceptible to the effects of agrochemicals, compared to other bees.

A study found that the Bt proteins Cry1F and Cry2Aa, and 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. Glyphosate was very toxic to the bee larvae, killing all of them within only a few days of exposure while bees treated with Cry2Aa and Cry1F proteins were delayed in their development.

This study underscores the need for further research to establish trustworthy methods of assessing the risks of glyphosate and Cry proteins for non-target species.