Development of Nest Attractant for the Blue Orchard Bee

Situation or Problem The blue orchard bee (BOB), Osmia lignaria, is a solitary, native bee species that has been demonstrated to be an excellent pollinator of almonds, cherries, apples, pears and other crops, but has yet to become available on a large scale. The economics and scientific knowledge are now in place for the BOB to become a commercial pollinator, but only if large populations of the bees can be supplied. One obstacle in raising these bees is that, at a minimum, 25% of the female bees allowed to emerge from their nests in an orchard will disperse from the intended pollination site. Dispersal can be greater (over 50%) when bees emerge from cocoons that were removed from their nests. Purpose In 2008, AgPollen conducted two field trials that showed that a BOB nest component could attract bees to construct more nests at a given site. For this project, we will build on that information using field and lab experiments. In California we will conduct two studies, one on almonds and one during propagation on wildflowers. In Utah, a third field trial will be conducted in an apple orchard. The nest component volatile chemicals will be extracted and identified. This will allow us to test various concentrations, fractions, and individual chemicals in our field tests. Chemicals will also be tested using a technique that can detect whether or not the bee can sense a particular chemical with its antennae. This research will seek a chemical or mix of chemicals that could be developed into a lure that will make nests more attractive to female BOBs.