Evaluating the risks of pesticides to pollinators has become an important issue for the scientific community and regulators. Multiple government regulatory agencies have developed guidance for completing risk assessments for bees. The United States Environmental Protection Agency, the Canadian Pest Management Regulatory Agency, and the California Department of Pesticide Regulations recently released ‘Guidance for Assessing Pesticide Risks to Bees’, and the European Food Safety Authority has also developed guidance on pesticide risk assessment for bees.
Although various forms of guidance are available, conducting refined risk assessments to evaluate risks to bees is not easy. The fate and behaviour of the pesticide, the life history of the different colony castes of honey bees, solitary bees, endangered bee species (e.g., Rusty Patched Bumblebee – Bombus affinis), exposure modelling, effect determinations, and numerous other factors must be addressed, and uncertainties captured.
To accurately estimate bee exposure via the diet, we must know what types of foods are being consumed, in what quantities, and at what times, relative to the use and fate of the pesticide. Exposure assessment is particularly challenging for small eusocial insects such as honey bees (Apis mellifera L.) that amend, store, and share food, and have multiple life stages and castes with different nutritional requirements. Accordingly, quality data and refined analyses are needed to parameterize both screening-level and refined dietary exposure models for bees. The timing, duration, and magnitude of exposure are critical in capturing uncertainty and characterizing risks.
Intrinsik has a large ecological risk assessment team with significant experience in developing refined exposure models. We provide significant support to registrants on endangered species issues. Currently, Intrinsik scientists and our partners are seeking to determine how much nectar, pollen, and supplemental food is collected, stored, and consumed over time by colonies, and how much nectar is transported, shared, and consumed by foraging bees. This information will be used to better characterize forager and colony exposure and to provide refined comments for pesticide risk assessments. Intrinsik has also conducted statistical analyses on residue levels in nectar and pollen which is a key consideration to determine dose for both individual bee and colony exposure. The knowledge developed by Intrinsik on these projects gives the company one of the most knowledgeable teams in the industry to undertake further work with these important species.