Incorporating a nectar‐based pesticide module into BeeHave, an agent‐based model of honeybee population dynamics

Honeybees are important pollinators for many agricultural food crops, and it is critical that the response of honeybee colonies to pesticides be included in pesticide risk assessments. However, honeybee colony dynamics are driven by complex interactions of ecological, physiological and chemical factors. Such complexity lends itself to a modelling approach to characterize colony responses to pesticides. The NetLogo‐based model BeeHave is a detailed model of honeybee colony dynamics. One recently released version of this model (BeeHave_BeeMap_PEEM) considers pesticide exposure via the pollen ingestion pathway. However, nectar ingestion is also a critical exposure pathway, and an exposure module via nectar is needed for this model. We adapted BeeHave to include a nectar‐based pesticide exposure module. Exposure is proportional to consumption of nectar and honey based on the energetic needs (kJ) of bee cohorts, and dose depends on the pesticide concentrations of nectar and honey. We assessed the model using a sensitivity analysis and by parameterizing the model to mimic a field‐based colony feeding trial. The resulting modelled counts of honeybee adults and eggs followed the expected dose‐based response of the parameterizing study, and were generally of the same magnitude. Solution . The addition of this module to BeeHave will allow for a comparison of predicted pesticide impacts via the nectar pathway with other honeybee colony models. Furthermore, by building on a prior pesticide exposure module, this version of BeeHave will also allow for the simultaneous estimation of pesticide impacts from two different exposure pathways.