Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms

Abstract

Over one hundred crop species grown by farmers in North America require insect pollinators in order to be most productive. In the past, native bees and feral honey bees could meet all of the pollination needs of orchards, fields of tomatoes or pumpkins, and berry patches. These farms were small and surrounded by or close to areas of natural habitat that harbored adequate pollinators to accomplish the task that now requires imported colonies of honey bees. Nearby natural areas also served as a ready source of new pollinators that could recolonize and provide pollination services after insecticide applications killed resident bees. Today, however, many agricultural landscapes are much more extensive and lack sufficient natural habitat to support native pollinators. The purpose of these guidelines is to provide information about native bees and their habitat requirements so that farmers can: 1) review current farm practices to see where to make simple changes to benefit native pollinators and farm productivity; 2) increase the ability of their land to support these bees; and 3) ultimately increase their reliance upon native bees for crop pollination. Making small changes to increase the number of native pollinators on a farm does not require a lot of work. Subtle changes in farm practices can involve identifying and protecting nesting sites and forage; keeping rotations of pumpkins and other squashes within an area of one hundred yards; allowing lettuce and other plants to bolt before plowing them under; or changing how pesticides are applied in order to have the least impact on native bees. Farmers with more time and interest can create additional habitat in areas of marginal farm production. For example, pollinator refuges can include bare, untilled ground or wooden nest blocks surrounded by native plants; a simple hedgerow of forbs and shrubs; or a pesticide- free buffer zone around the edges of fields. Why focus this attention on native bees, but not on honey bees? Here are just four of many reasons (more are explained in detail throughout these guidelines): 1) Bumble bees pollinate tomatoes, watermelon, blueberries, and cranberries much more effectively than honey bees. 2) Honey bees can be in short supply at critical times. The overall trend in the U.S. is a 1 percent reduction in the number of available colonies per year. 3) Native bees have been shown to pollinate crops effectively when enough natural habitat is available to support nest sites and forage. 4) Native bees can make honey bees more effective as pollinators by causing them to move between rows of pollenizers and the focal crop more often. Finally, managing marginal areas of a farm for native bees should not be confused with beekeeping. There are no hives, no need for special safety equipment, and no reason to handle any bees. In addition, most of these valuable pollinators don’t sting!