Antibiotics disrupt thermoregulation in honey bees

Antibiotics are widely used in animal agriculture, including commercial apiculture. Antibiotics are used prophylactically and therapeutically for disease. However, recent research demonstrate that antibiotics negatively impact honey bees, increasing disease susceptibility and mortality. Although much is known of the consequences antibiotics have on honey bee health, their effects on behavior are only beginning to be elucidated. Honey bees closely coordinate individual behaviors with nestmates to regulate colony tasks. One such task is thermoregulation. Honeybees must maintain colony temperatures at 35°C ± 1°C to ensure proper development of brood. In response to thermal stress, honey bees collectively fan their wings to circulate cool air into the colony. Thus, if this behavior is perturbed, it could mean colony-wide breakdown of critical thermoregulation. In this study, we hypothesized that antibiotics changes fanning behavior. Using an established assay to assess fanning, we show that honey bees treated with terramycin, a common antibiotic used in beekeeping, are significantly less likely to fan in response to temperature stress than bees fed a control sucrose solution. Further, antibiotic-treated bees begin to fan at significantly higher temperatures. We then wanted to know whether this was a result of disrupted social interactions, as our previous work suggest that interactions facilitate fanning. Using tracking software to evaluate interaction networks, we demonstrate that antibiotic-treated honey bees interact with each other significantly less than controls. These results provide crucial insight into the effect of widespread usage of antibiotics on insect biology, highlighting the importance of considering behavioral detriments particularly in social animals.