Pollinators in Washington pears, research review and ongoing projects

Washington state is the leading producer of pears in the United States, with the center of production being the Wenatchee River Valley. The two predominate cultivars grown in the state are ‘Bartlett’ and ‘Anjou’, both of which require sufficient cross-pollination to achieve consistent fruit set. Pears are typically in bloom in early April in this area. The European honey bee is the primary pollinator of pears in this region. While the honey bee has done an adequate job of pear pollination, concerns remain about its effectiveness such as low crop fidelity and reputation as a fair weather flyer. These problems can be somewhat alleviated by using attractants and supplemental food for the hives. Other managed bee species have been studied as potential pollinators of pears such as Bombus vosnesenskii, B. occidentalis, and Osmia lignaria. The usefulness of these species is mixed. Only one species of wild bee has been documented in the United State pollination pears, Andrena nivalis. This year, we began preliminary research into pear pollinators investigating the effectiveness of Bee-Scent, sampling for wild bee species, and observing other pollinators that are present in a pear orchard. The results and future work will be discussed.