Location: Pollinating Insect-Biology, Management, Systematics Research
Project Number: 2080-30500-001-040-A
Project Type: Cooperative Agreement
Start Date: Aug 1, 2025
End Date: Jan 31, 2026
Objective:
In the United States, Osmia lignaria is the dominant managed species, and has been successfully utilized in orchard pollination (primarily almonds, apples, and cherries). Osmia lignaria utilization has been particularly successful in a co-pollination strategy in almond production, where normal stocking rates of honey bees can be reduced from two colonies per acre to one colony per acre, with the addition of 1000 O. lignaria per acre alongside the honey bees. Having a combination of honey bees and Osmia lignaria has been shown to increase nut set (Pitts-Singer et al, 2018). The added pollination benefit provided by having Osmia, with good bee returns (high rates of Osmia nesting) in the field to supplement next year’s pollination, can help to reduce the overall production costs for growers, and increase farm profitability. The overarching aim of this work is to establish additional Osmia species for commercial management targeting berry crops.
Objective 1: Develop optimal nesting blocks for O. ribifloris, O. bruneri, and O. aglaia to maximize bee returns.
Objective 2: Test overwintering management regimes to maximize survival and optimize the timing of bee releases for target crops.
Objective 3: Test bee release strategies to optimize bee nesting and reduce absconding behavior.
Approach:
Objective 1: Develop optimal nesting blocks for O. ribifloris, O. bruneri, and O. aglaia to maximize bee returns - Cooperator will test the preferences of each Osmia species (O. bruneri, O. ribifloris, O. aglaia) for different nesting materials (wood laminates, reeds, various inner wall diameters) by providing a variety of materials and monitoring nesting abundances during field deployment.
Objective 2: Test overwintering management regimes to maximize survival and optimize the timing of bee releases for target crops - Cooperator will test Osmia bruneri overwintering conditions, including various overwintering lengths (180 - 200 days) and temperatures (5 - 7 degrees C) using incubators. Cooperator will then monitor rates of bee emergence following each overwintering treatment and survival rates.
Objective 3: Test bee release strategies to optimize bee nesting and reduce absconding behavior - Cooperator will test if use of an Osmia attractant spray applied to nesting blocks increases rates of Osmia ribifloris nesting when bees are released in berry crop fields. Cooperater will set up two nesting blocks per field, 5 meters apart, and one will have the attractant spray and the other will serve as a control. 30 Osmia ribifloris will be released at each nesting block and nesting will be monitored throughout the field season.