Marquette researchers find common agricultural antibiotic disrupts honeybee teamwork, raising concerns for pollinator health 

Marquette University researchers have found that Oxytetracycline, a common antibiotic used in agriculture, disrupts a critical social behavior in honeybees. Honeybees treated with the antibiotic moved faster but reduced participation in fanning the hive, a critical social behavior necessary to keep their colony cool when it gets hot during the summer. 

The findings were published by Dr. Chelsea Cook, assistant professor of biology, and Justine Nguyen, graduate researcher in the Cook Bee Research Lab, on March 19, in Proceedings of the Royal Society B: Biological Sciences. 

Like humans, bees can get bacterial infections and are prescribed antibiotics. Medication can often have side effects that impact how animals feel. Oxytetracycline is commonly used to treat and prevent infections in many farm animals, including honeybees, which are important agricultural pollinators. 

“When we treat honeybees with antibiotics, we know that some parts of their health are affected, but very few studies have looked at whether antibiotics mess with their ability to work together as a result of these side effects, which is very important to test because honeybees rely on teamwork to survive,” Nguyen said. 

To look at this behavior, Nguyen treated bees for either one day or five days to mimic a short-term or a long-term treatment. When bees were treated with antibiotics for five days, they didn’t fan as much as bees that were not treated, meaning that they weren’t able to do the job properly. 

“If bees are sick, they need treatment – we don’t want to dissuade the use of antibiotics when needed – but we do want to understand the impacts that medications may have on the bees, just like we want to know the side effects to our medications,” Cook said. 

To discover why this happened, the team video recorded the bees as they experienced hot temperatures and evaluated how much or how fast they moved and how they interacted. The team found the antibiotic-treated bees moved faster but interacted less with the other bees. This might indicate that the antibiotics were impacting how the bees moved and interacted with each other, which impaired their ability to work together to fan. 

“Honeybees are an excellent model system for social behavior and are so important for our agricultural system – they pollinate many crops that we eat and export,” Cook said. “This work helps us to understand how common treatments that beekeepers use might impact their ability to work together and keep themselves healthy.” 

Honeybees work together to do all the jobs in their colony, such as collecting all the food for the colony and maintaining the colony conditions, like temperature. With social behaviors critical for colony maintenance, when a honeybee has a side effect from a medication, that might impact the ability for the entire colony to function. The Cook Bee Research Lab studies fanning behavior. This work helps scientists understand how these important pollinators work together to keep their societies functioning, and what impacts we may have on them as we manage their colonies.