Modeling Nonlinear Survival Dynamics of Honeybee Colonies Under Combined Stressors

ABSTRACT Honeybee colonies provide critical pollination services but continue to experience high losses due to multiple stressors. This study developed a simulation framework integrating agricultural resources, urban habitat loss, pesticide stress, and parasite dynamics to examine colony survival under 20,000 parameter scenarios. The mean final survival fraction was 0.77, but the 5th percentile was reduced to 0.48 and reached a minimum of 0.28, indicating that stability at the average conceals severe risks in the distributional extremes. Survival declined abruptly when pesticide lethality exceeded 0.4 and the urban index surpassed 0.7, reflecting nonlinear responses and thresholds that cannot be detected in single‐factor analyses. Random Forest and regression models confirmed that pesticide toxicity and habitat degradation were the primary determinants of survival, while pathogen‐related variables such as Varroa reproduction contributed minimally. These results indicate that colony persistence is shaped less by gradual declines than by sharp contractions under interacting pressures, and that management strategies focusing mainly on pathogen control may underestimate the destabilizing role of chemical and habitat stressors. Although the model does not capture heterogeneity in pesticide residues, landscape‐level foraging variation, or long‐term climatic influences, it provides a framework for resilience‐oriented risk assessment that emphasizes distributional extremes and nonlinear stressor interactions with direct implications for pollinator management and agroecosystem stability.