2025 American Bee Research Conference proceedings
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EmailConference presentation abstracts highlight current research and extension work on beekeeping and honey bee health topics. These presentations included research and extension program updates from Michigan State University.
In January 2025, the American Association of Professional Apiculturists held its annual American Bee Research Conference (ABRC) in conjunction with the American Beekeeping Federation’s annual convention in Reno, Nevada. Bee Culture published ABRC abstracts in two parts: 2025 ABRC Proceedings Part 1 and 2025 ABRC Proceedings Part 2. Bee Culture has also published ABRC abstracts from previous years. These abstracts may be of interest to beekeepers who are interested in learning about apiculture research that is underway and new research findings.
ABRC presentations included Michigan State University apiculture research and extension. Graduate student Peter Fowler presented research conducted with Assistant Professor Meghan Milbrath, “Molecular diversity and antibiotic susceptibility of Melissococcus plutonius.” Fowler received an award from the American Association of Professional Apiculturists for his presentation.
Associate Professor Zachary Huang presented research, “Fire retardant Phos-Chek LC95A toxicity to honey bee workers.” Apiculture Extension Educator Ana Heck presented an extension program, “Emergency response to transportation accidents involving honey bees.” Meghan Milbrath also contributed to the extension program and to research presented by a co-researcher, “Pesticide risk to bees: What we know and what we need to know better.”
The abstracts from these presentations are shared below.
Molecular diversity and antibiotic susceptibility of Melissococcus plutonius
Oral presentation
Fowler PD, Moricz BS, Milbrath MO
European foulbrood has become endemic among apiaries in Michigan with 1 in every three colonies sampled containing the causative bacterium M. plutonius. Only one antibiotic is approved for treatment of EFB in the United States, oxytetracycline, which has been used for disease management since the 1950’s. However, due to the difficulty of culturing M. plutonius in the lab, little is known about both the molecular diversity circulating in US apiaries and whether resistant strains have emerged. Here we use whole genome SNP analysis to analyze a broad set of M. plutonius isolates spanning multiple beekeepers and years. Three isolates were selected from each genetic grouping and tested for susceptibility to oxytetracycline using standard CLSI guidelines on two commonly used media. Every isolate tested remained susceptible to oxytetracycline 96 hours after inoculation. However, many strains remained viable on substrates with very high concentrations of antibiotic, showing growth after antibiotic efficacy waned with wide variability in growth rate and characteristics between variants, media type and age of media. These results suggest that M. plutonius may be persisting in honey bee colonies after treatment through mechanisms that remain to be elucidated.
Fire retardant Phos-Chek LC95A toxicity to honey bee workers
Oral presentation
Huang ZY, Chen L
Phos-Chek LC95A is commonly used to suppress forest fires, especially in California. This is normally done from an airplane, thus honey bee colonies can be exposed to this fire retardant. Beekeepers have reported colony mortality after “pink droplets” on top of hives after airplanes have passed the area dropping the agent. We assessed honey bee mortality in both newly emerged bees and returning foragers after they were misted with Phos-Chek LC95A or water only as a control. We found very little evidence of strong toxicity of this agent to honey bees, even when using foragers from colonies with high mite infestation. It is possible, but unlikely, that this agent might be passed to open brood and cause colony collapse.
Emergency response to transportation accidents involving honey bees
Oral presentation
Heck A, Milbrath M
Michigan State University Extension’s (MSU Extension’s) animal agriculture team developed the Emergency Response to Accidents Involving Livestock program in 2018 to train first responders to deal with livestock transportation accidents. The program includes hands-on training sessions, online resources, and emergency response trailers throughout the state that contain response equipment. In 2023, the team added honey bees to the program to address the diversity of Michigan’s agriculture industry. Many first responders who attend training sessions on honey bees express they had never thought about honey bee hives on roadways or how to respond to an accident involving honey bee colonies. MSU Extension explains to first responders how common it is for honey bee colonies to be transported throughout Michigan and teaches them how to respond to an accident, minimize stings, prevent a stalled load from overheating and contact migratory beekeepers to respond. MSU Extension’s Emergency Response to Accidents Involving Livestock program is an example of successful cross-species programming. These successes are supported by evaluation data, funding support, stakeholder feedback and effective responses to transportation accidents involving livestock. The program aims to protect the safety of first responders and the public, promote animal welfare and support agriculture producers, including beekeepers.
Pesticide risk to bees: What we know and what we need to know better
Keynote address
McArt SH, Mueller TG, Graham KK, Milbrath MO, Isaacs R, Muniz PA, Sossa DE, Baert N, Anderson W
Estimating pesticide risk to bees requires knowledge of two factors: exposure and toxicity. What do we know about patterns of exposure in the real world? What do we know about toxicity? How do scientists integrate exposure and toxicity data to estimate risk? When is risk from pesticides high vs. low in the real world? Are protections from regulatory agencies adequate for minimizing harmful effects of pesticides on bee populations? This talk will dig into my lab’s efforts to answer these questions. I will show that we know remarkably little about pesticide exposure in the real world, that adult honey bee LD50s are an inadequate metric for toxicity, and that several parameters in current regulatory agency risk metrics are either unknown or biased to underestimate risk. This said, current pesticide risk assessment methods show that risk during day-to-day beekeeping is generally low, while risk during crop pollination and planting of neonicotinoid-treated corn and soybean fields is frequently high enough to negatively impact bee populations. If progress is to be made on this topic, scientists must step out of the academic bubble and interact directly with farmers, beekeepers, crop consultants, regulatory agencies and the pesticide industry.
Acknowledgments
Thank you to the following partner organizations for providing financial assistance, promotion or both to the Emergency Response to Accidents Involving Livestock program: Michigan Department of Agriculture and Rural Development, Michigan Pork Producers Association, Michigan Turkey, United Dairy Industry of Michigan, Michigan Association of Animal Control Officers, Michigan Commercial Beekeepers Association, Michigan Beekeepers Association and Michigan State Police.
This work is supported by the Crop Protection and Pest Management Program [grant no 2024-70006-43569] from the USDA National Institute of Food and Agriculture.
This work was funded through The Rackham Research Endowment Program, Project GREEEN (Project GREEEN Proposal #GR21‐033) and North Central SARE (Award #GNC21-325).
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.
