The role of pesticides in pollinator declines

There is a growing concern that pollinators are in decline, potentially threatening biodiversity and sustainable food production on a global scale. In general, there is consensus on the multifactorial origin of this problem, and pesticides are regarded as one of the factors involved. Pollinators can be exposed to pesticides through different routes, and the consequences of such exposure depend on whether the levels of field exposure overlap the toxic thresholds considered as detrimental to their health. Several studies have shown the harmful effects of some pesticides not just at their lethal concentrations, but also at lower concentrations (sub-lethal) which are often detected in the floral resources consumed by pollinators. In order to direct future research that may fill our current knowledge gaps, it is essential to identify the levels of pesticides and mixtures to which bees are exposed to, and the consequences of such exposure, so as to guide pesticide regulation strategies that may guarantee the conservation of these crucial organisms.