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ARS Home » Southeast Area » Baton Rouge, Louisiana » Honey Bee Lab » Research » Publications at this Location » Publication #419442
Research Project: Using Genetics to Improve the Breeding and Health of Honey Bees

Location: Honey Bee Breeding, Genetics, and Physiology Research

Title: Hangry bees: Pollen dearth impacts honey bee (Apis mellifera) behavior and physiology

Author
item Walsh, Elizabeth
item Avalos, Arian
item Ihle, Kate
item Lau, Pierre
item Simone-Finstrom, Michael
item Acosta, Anabelle
item Frake, Amanda
item Obrien, Sharon
item Tundo, Giovanni-Pao

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2025
Publication Date: 1/16/2026
Citation: Walsh, E.M., Avalos, A., Ihle, K.E., Lau, P.W., Simone-Finstrom, M., Acosta, A., Frake, A.M., Obrien, S.L., Tundo, G. 2026. Hangry bees: Pollen dearth impacts honey bee (Apis mellifera) behavior and physiology. PLOS ONE. https://doi.org/10.1371/journal.pone.0338712.
DOI: https://doi.org/10.1371/journal.pone.0338712

Interpretive Summary: Drought can cause physiological, metabolic, and behavioral changes in honey bees, a vital livestock species for human food security. Managed honey bees are routinely evaluated by utilizing small number of biomarkers or behavioral assays. Here, we studied honey bee physiology, metabolism, and behavior changed after a realistic period of pollen deprivation. We found meaningful changes in physiology, metabolism, and behavior which together show a compelling picture of how pollen deprivation, such as that experienced during a realistic drought, affects honey bee health and behavior. These findings showcase the importance of holistic evaluations of livestock species before management decisions are made.

Technical Abstract: A combination of frequent droughts and landscape fragmentation causes increasing nutritional deprivation and stress for various livestock species, including honey bees (Apis mellifera). To investigate the effect of a realistic nutritional pollen deficiency over a month or more, we simulated a pollen dearth in half of our experimental colonies by robbing incoming foragers of their pollen loads at the colony entrance. We then conducted aggression assays on each colony weekly for pollen deprived and control counterparts. We additionally examined hypopharyngeal glands, quantified lipids, quantified gene expression, and identified the plant species bees foraged from. We found that seasonal changes likely had a greater impact on bee physiology and gene expression than the simulated pollen dearth, indicating that bees are very physiologically resilient to environmental variation. We also found that colonies deprived of pollen reacted by becoming more defensive, suggesting that the simulated environmental stress caused extreme behavioral changes. Temperament is traditionally thought of as a genotypic static state, but this work shows that there are environmental cues which have gone unrecognized. Furthermore, all physiological evaluation variables examined in isolation do not lead to an accurate conclusion of what caused an extreme change in behavior, which highlights the need for holistic evaluations to form accurate conclusions.