The expansion of agribusiness: harmful impacts of deforestation, pesticides and transgenics on bees

Abstract

The benefits that bees offer the ecosystem are increasingly recognized, but not met by actions designed to conserve these pollinators. Therefore, the present work aims to describe the impact of three key characteristics of agroindustry that are currently damaging bees in Brazil: deforestation, use of pesticides and large-scale cultivation of genetically modified (GM) varieties. We hear of mass mortality and weakening and damage to hives, but no conclusive causes are announced. In particular, studies indicate that fungicides, herbicides and GM plants, even when considered harmless to bees, still promote physiological and behavioral changes in these insects. However, most of these studies do not indicate the real damage to the hives, which can only be observed in long-term studies carried out in the field. Even when risk assessments of fungicides and herbicides are conducted in the field on non-targeted organisms, the tests are considered valid for isolated individuals without regard to the eusocial behavior of bees in their colonies. Some studies present results from experiments performed on individuals in the lab, again not necessarily reflecting hive activity. Results of trials that consider the complexity of interactions among castes and different generations of bees are very scarce. Therefore, we herein take a comprehensive and detailed approach to three practices of Brazilian agribusiness that directly affect bee and colony health and survival, as well as their ecoservices.