"A shift in perspective from a bee-only focus is needed for assessments of crop pollinator biodiversity and the economic value of pollination. These studies should also consider the services provided by other types of insects, such as flies, wasps, beetles, and butterfliesimportant pollinators that are currently overlooked. ..."
Read research here: Proceedings of the National Academy of Sciences of the United States of America
Read sumary/article here: Bees not be-all and end-all in crop pollination {Australian Geographic}