Effects of Imidacloprid Soil Drench Applications on Nesting Blue Orchard Mason Bees (Osmia lignaria)

View the project final report

Commodities

• Animals: bees

Practices

• Animal Production: animal protection and health
• Crop Production: pollination, pollinator habitat, pollinator health

This project seeks to elucidate the multiple pathways by which wild bees may be impacted by neonicotinoid pesticide residues in soils that are used for nesting material. While significant progress has been made with regards to our understanding of the impact of neonicotinoid pesticides on honeybees and dietary exposure to residue in pollen and water, little is known about other exposure pathways which may exist for wild bees which use a variety of materials beyond pollen and nectar to complete their life cycles. Use of mud by mason bees (Osmia spp.) is thought to be a potential source of exposure to pesticide residue which has not been examined. This project represents the first attempt to look at nesting materials as a potential exposure pathway for mason bees to neonicotinoid pesticides.

Objective 1: To determine how adult female mason bee nest establishment is affected by imidacloprid soil drench treatments when treated mud is used for nesting.

Objective 2: To determine how offspring which develop within nests with treated soil are affected, in terms of survivorship and sublethal effects such as size, weight, and sex ratio.

Objective 3: To determine if female mason bees will detect or choose soils with lower residual concentrations of neonicotinoid.