Evaluating Osmia cornifrons as Pollinators of Highbush Blueberry

The objective of this study was to investigate the use of Osmia cornifrons Radoszkowski (hornfaced bees) as a pollinator of Vaccinium corymbosum L. (highbush blueberry). Currently, there are no reports available on hornfaced bee use for commercial blueberry production. Five pollination treatments were compared in a 2-year evaluation (2005-06) including hornfaced bees, honeybees, bumblebees, native pollinators, and no pollinators. Enclosed pollination cages were constructed around mature, field-grown highbush blueberry plants to prevent mixing of pollination treatments. Each cage contained a single pollination treatment, except for the open pollination and no pollination treatments. The five pollination treatments were replicated three times inside separate pollination field cages on the farm. Three branches per plant were randomly selected that had a minimum of five fruiting buds and blossom number was recorded. After pollination occurred, the cages were removed to allow the berries to ripen. Ripe fruits were picked weekly over the fruiting season (July to August) in each year (2005 and 2006), with the fruit from each sample being counted and weighed. Blossom number was compared to fruit number and weight to determine efficiency of pollination as a result of the pollination treatments. The results showed that hornfaced bees can be a successful pollinator of commercial highbush blueberry under pollination field cage conditions.