Location: Pollinating Insect-Biology, Management, Systematics Research
Project Number: 2080-30500-001-045-A
Project Type: Cooperative Agreement
Start Date: Dec 23, 2025
End Date: May 31, 2028
Objective:
Objective 1: Assess the optimal seed mix for both the attractiveness/nutrition of Osmia lignaria and the feasibility and success of growing these mixes in the Great Basin region.
Objective 2: Determine the appropriate stocking density of O. lignaria in field cages and assess the ability to scale up the stocking density to large enclosures.
Objective 3: Determine yearly behavioral changes of the bee and assess yearly variation in the native pest communities.
Approach:
We will test two seed mixes to find the most productive pollen and nectar providers for southwestern Idaho/ northern Utah. An ideal flower mix provides a long bloom period that starts early in the growing season, with abundant pollen and nectar resources for the bees. Previous experience in California has shown that weeds and disease can be a problem in wildflower plantings. Transplanting can solve this issue if these problems are prevalent in Idaho. Additionally, growing seeds in greenhouse first can eliminate the problem of harsh winter prevent blooming in time to propagate Osmia.
In 20x20 cages we will measure bee reproductive ability in the enclosure at different stocking rates. Prior research has shown that cages can support at least 10 – 15 females, however we will build upon this data to maximize the rate of reproduction without introducing intraspecific competition for both floral and nesting resources. Reproductive health will be measured by nest construction time and foraging time by foraging females, sex ratio, offspring adult body size and overall larval survival. The best seed mix from objective 1 should minimize the time for females to collect a full pollen load and the time to complete an entire nest. Typical larval mortality tends to be between 60 – 65%, in these cages we will strive for larval mortality to be less than 10%. Once stocking rates in the cages are established, we will use those numbers to ask if stocking rate is linear based on square footage, i.e. can we just double the number of bees added to a 20x40 cage. This will allow us to make recommendations to growers on maximum stocking densities in large agricultural enclosures.
Parasites, pathogens and pollen balls are some of the leading causes of immature mortality for this managed O. lignaria. We will determine the composition of the native pest guild in the area and measure the phenology of each pest species. Monodontomerus sp. is a key pest that we will need to monitor and our ideal seed mix from objective one should also be early enough to avoid overlapping with this parasitoid’s natural activity timing. Other pests that we will monitor, and control include Sapyga sp., Stelis montana, hairy-fingered mite and Ascophaera spp ., the pathogen that causes chalkbrood. Reducing the impact of these pests should mitigate losses both economically and ecologically. Additionally, it has been hypothesized that pollen balls are due to improper diets and/or pesticides which will be closely monitored in these enclosures to reduce the loss of pollen balls.