That’s what entomologists from the University of Wisconsin-Madison seek to learn. According to Phil Pelliterri of the Insect Diagnostic Lab, about 4,000 species of insects are known to pollinate hundreds of varieties of human food-source plants in the U.S. Our working pollinators do have contractual requirements though — quoting Pelliterri:
You can’t have native pollinators with a bunch of parking lots. You have to promote patches of native ground, flowers, prairie or oak savanna, so the bees have a food source and habitat to nest in the ground.
Read more here.