Fifty-eight bee researchers say wild bee diversity is declining worldwide at unprecedented rates, and steps must be taken to conserve them -- and not just those that are the main pollinators of agricultural crops.
Researchers studied 785 species visiting crop flowers, analyzing which provide the best economic returns from crop pollination.
They found that wild bee communities provide the same economic contributions as managed honey bee colonies.
But researchers said the majority of crop pollination by wild bees are accomplished by only about 2 percent of the most common species.
Wild bees, or non-managed bees, include bumble bees, sweat bees and small carpenter bees.
The researchers analyzed data from more than 90 studies on five continents, including Europe and North America.
"This study provides important support for the role of wild bees to crop pollination through a comprehensive global summary," said Neal Williams, study co-author and associate professor
in the UC Davis Department of Entomology and Nematology.
"At the same time, we found that in any one region, much of the pollination services from wild bees to a given crop come from just a few species, thus we need to be careful about using a simplistic economic ecosystem-services argument for biodiversity conservation and maintain actions that target biodiversity as specific goal," he said.