Investigating the effect of a commonly used apiculture antibiotic on honeybee colony thermoregulation and health

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Investigating the effect of a commonly used apiculture antibiotic on honeybee colony thermoregulation and health

The overuse of antibiotics in agriculture has led to a public health crisis in increased antibiotic resistance and toxicity in our managed livestock and agricultural land. Thus, research into how antibiotics impact fundamental aspects of animal husbandry is essential to address this crisis. During the management of Western honeybee (Apis mellifera) populations for the pollination of crops and honey production, beekeepers often use antibiotics approved for livestock to prophylactically prevent or treat diseases in their colonies. Recent studies have shown that antibiotic treatment may be a detriment to honeybee livelihood and could be contributing to the huge loss in colonies annually. However, few studies have investigated the effect of antibiotics on honeybee behavior, which is critical to consider because honeybees are highly social animals that depend on tight coordination of behaviors to maintain optimum colony function. Any disruption of these behaviors can potentially contribute to colony failure. An essential behavior that honeybees perform is fanning, a thermoregulatory behavior performed at the entrance of the colony to keep internal temperatures at 95°F for proper brood development. My previous data, obtained in a laboratory setting, demonstrates that fanners treated with antibiotics are less likely to fan and are unable to quickly respond to heat stress. Therefore, the central hypothesis for my NCR-SARE project is that prophylactic colony-wide antibiotic treatment will disrupt proper thermoregulation. To test this hypothesis, I will work with a commercial Wisconsin beekeeper and monitor the temperatures of a subset of his colonies before and after antibiotic treatment using temperature sensors. I will couple this temperature data with behavioral observations of fanning at the entrance of the colony and measurements of colony health such as colony weight, gut microbiome composition, mite counts, and bee mortality, as it is possible that colony temperatures are maintained at the cost of colony health. Project outcomes are 1) generating key data to be presented at national scientific conferences and published in both science and beekeeping journals and 2) educate beekeepers on best practices regarding the usage of antibiotics in their hives. We will evaluate the success of my project through rigorous data analysis and measuring overall engagement with my planned talks and surveys. If funded, this research will be the first NCR-SARE graduate student research project to investigate the effects of prophylactic antibiotics on honeybee behavior and health.

Because of research exposing the effects of antibiotic use on honeybee health, the Food and Drug Administration’s (FDA) Center for Veterinary Medicine recently passed the Veterinary Feed Directive (VFD) initiative, which requires beekeepers to obtain a veterinary prescription to purchase antibiotics. However, many beekeepers have expressed concern that this initiative will lead to diseases like American Foulbrood to resurge and cause increased colony loss. Thus, many beekeepers appear to be unaware of the adverse effects antibiotics have on honeybee livelihood and may not understand the need for such an initiative. Therefore, the following outcomes are expected on completion of my project:

Learning outcomes (through talks, presentations, and course curriculum):

• Researchers will understand the effect of antibiotic on temperature regulation of hives
• Beekeepers will understand the risks of prophylactic antibiotic use for colony health and behavior

Action outcomes:

• Beekeepers will stop using antibiotics except when treating active diseases
• Reduced financial strain in replacing their colonies annually
• Reduced contributions to antibiotic pollution in the environment