Wild bee pollinators provide the majority of crop visitation across land-use gradients in New Jersey and Pennsylvania, USA

1 Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA; 2 Department of Biology, Bryn Mawr College, 101 N. Marion Avenue, Bryn Mawr, PA 19101, USA; 3 Department of Entomology, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA; 4 Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA; 5 Department of Environmental Science, Policy and Management, University of California, Berkeley, 137 Mulford Hall, Berkeley, CA 94720-3114, USA