Worldwide occurrence records reflect a global decline in bee species richness

Wild and managed bees are key pollinators, providing ecosystem services to a large fraction of the worlds flowering plants, including [~]85% of all cultivated crops. Recent reports of wild bee decline and its potential consequences are thus worrisome. However, evidence is mostly based on local or regional studies; global status of bee decline has not been assessed yet. To fill this gap, we analyzed publicly available worldwide occurrence records from the Global Biodiversity Information Facility spanning more than a century of specimen collection. We found that after the 1980s the number of collected bee species declines steeply, and approximately 25% fewer species were reported between 2006 and 2015 relative to the number of species counted before the 1990s. These trends are alarming and encourage swift action to avoid further decline of these key pollinators.