Role of Native Bees in Apple Pollination

to be eff ective vectors of apple pollen.” Pollination is an essential step in production of fruits and many vegetables. Th e most widely used insect for fruit pollination is the European honey bee, Apis mellifera. Honey bees are ideal pollinators in many crop systems: each colony produces thousands of foraging workers and colonies can be moved into orchards and fields during the flowering period. Th ey are especially important pollinators in large-scale, highly disturbed agroecosystems (the Central Valley of California, for example). However, honey bee populations in North America (NA) and Europe are in decline (Aizen & Harder 2009), primarily due to heavy pathogen and parasite loads (Ratnieks & Carreck 2010). Problems of honey bee health became particularly acute in 2007/2008 when many colonies across N. America experienced colony collapse disorder (CCD). Th ere is most likely no single pathogen involved in CCD (Oldroyd 2007, Ratnieks & Carreck 2010). It appears more and more likely that a combination of pathogens and stresses (e.g., pesticide exposure, long-distance transportation associated with migratory beekeeping) are involved. It is also important to keep in mind that honey bees are not native to NA; they were introduced in the 1600s by early European colonists. While honey bees are important, they are certainly not the only crop pollinators (National Research Council of the National Academies 2006). Native bees (species of bees that are native to NA) play an important, but underappreciated, role in crop pollination. Bees are an enormously diverse group. Th ere are over 20,000 species of bees in the world (Michener 2007), approximately 4000 species in NA, and approximately 450 species in New York State (NY) alone. One potential solution to the decline in honey bee populations in NA is to examine the role that native bees are playing in crop pollination and to develop management practices that promote and maintain healthy native bee populations in and around agricultural areas. A number of recent studies in agricultural systems have suggested that native bees play an important role in crop pollination (Kremen et al. 2002; Winfree et al. 2007). However, we are just beginning to understand the conditions under which native bees may play an important role. Apples are an important crop in NY. New York State is the second largest producer of apples in the United States with an average of 25 million bushels of apples produced annually by a total of approximately 694 commercial growers and annual sales reaching $261 million (USDA NASS, 2008; http://www.nass. usda.gov/). Th ere are an estimated 17,000 people who work in the handling, distribution, marketing, processing and shipping of apples in NY. Bountiful apple harvests would not exist if it were not for bee pollinators. In 2008, we began a project to investigate the abundance and diversity of native bees in apple orchards in NY. Our goal was to determine if native bees provide a viable alternative to honey bees in apple pollination and to provide growers with advice on how to maintain native bee diversity and abundance. Specifi cally, our project has two main goals: (1) assess grower awareness and perceptions regarding pollination services provided by native bees and (2) survey bee diversity and abundance in apple orchards of various size and management regime.