Bees need à-la-carte pollen diets

Current global changes negatively impact insect pollinators, which directly impacts the pollination of wild and domesticated flowering plants and the functioning of ecosystems. Amongst these threats, many synergistic drivers, such as habitat destruction and fragmentation, increasing use of agrochemicals, decreasing resource diversity, as well as climate change, are known to affect wild and managed bees. All these drivers potentially have a direct or indirect impact on the nutritional quality of pollen collected by female bees to feed their larvae. This study contains an extensive dataset of the chemical composition of pollen collected by the European honeybee (Apis mellifera), the buff-tailed bumble bee (Bombus terrestris), and the red mason bee (Osmia bicornis) sampled at 128 sites across eight European countries in landscape gradients dominated by two major bee-pollinated crops (apple and oilseed rape). The data offer the opportunity to test whether variation in the nutritional quality of pollen diet is structured by species-specific traits, environmental factors, and/or drivers of global change. We show that the bees were able to collect resources of similar chemical qualities in the 8 countries. We also show that the three species collected resources of similar values in terms of total protein concentration but different lipid concentration. These preliminary results confirm the hypothesis of interspecific variation in nutritional requirement of bees.