RESUMO
Bees are major pollinators of both native flora and cultured crops. Nonetheless, despite their key functional role in ecosystems and agriculture, bee populations have been affected worldwide by deforestation and contamination by insecticides. Conversely, little is known about the effects of pesticides on morphogenetic development of neotropical stingless bees. We compared the fluctuating asymmetry (FA) in newly emerged bees and foragers of Melipona quadrifasciata anthidioides exposed to pesticides (experimental greenhouse and cultivated field). In addition, visitation behavior of foragers was inferred from pollen analyses and direct observation. A significant increase of FA (P < 0.001) was detected in bees from the greenhouse. Even though pesticides might affect their development, foragers seem to avoid contaminated plants whenever possible, as confirmed by pollen and visitation analyses. Consequently, the conservation of natural forests in agricultural landscapes is essential to ensure the health of colonies in stingless bees.