Incorporating a nectar-based pesticide module into BeeHave, an agent-based model of honey-bee population dynamics

Honey bees are important pollinators for many agricultural food crops, and
the response of honey bee colonies to pesticides must be included in
pesticide risk assessments. However, honey bee colony dynamics are driven
by complex interactions of ecological, physiological, and chemical
factors. Such complexity lends itself to a modeling approach to
characterize colony responses to pesticides. The NetLogo-based model
BeeHave is a detailed model of honey bee 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 modeled
counts of honey bee adults and eggs followed the expected dose-based
response of the parameterizing study, and were generally of the same
magnitude. The addition of this module to BeeHave will allow for a
comparison of predicted pesticide impacts via the nectar pathway with
other honey bee 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.