video: Honey bee hygiene: Cannibalism. view more
Credit: Siefert et al, 2021, PLOS ONE (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
Unique video from within beehives provides special insight into honey bee behaviors, according to a study published March 17, 2021 in the open-access journal PLOS ONE by Paul Siefert from Goethe-Universität, Germany, and colleagues.
Though the European honey bee (Apis mellifera) famously lives in large and complex colonies, it's the collective behavior of the hive's unique individuals that determines the colony's success--behaviors such as nest building, foraging, storing and ripening food, brood nursing, temperature regulation, hygiene, or hive defense. Most of these activities happen within the structure of the hive itself and aren't easily observable--but in this study, Siefert and colleagues were able to video record individual honeycomb frames and even cells from within special glass-framed observation hives, providing new insights into honey bee behavior at the individual level.
For these videos, the authors continuously recorded truncated honeycomb cells within the brood area of their observation hives with the frames turned 90 degrees for visibility, permitting a sideways view into the cells in the middle of the colony.
The recordings show a range of worker, offspring, and queen behaviors within the brood cells, including the queen's egg laying; embryonic hatching and larval cocooning; nurse worker bees' inspection and feeding of larva; workers' use of wax scales and existing nest material to remodel combs; storage of pollen and nectar in cells; and hygienic practices, such as cannibalism, grooming and surface cleaning. Additionally, Siefert and colleagues captured several processes previously undocumented, such as mouth-to-mouth feeding from nurse bees to larvae as well as nurse bee thermoregulation within cells containing the developing brood prompting the descent of eggs within their comb cells.
The wealth of video recordings providing specific instances of honeybee behavior will prove insightful for scientists as well as beekeepers and the general public. The authors especially hope their material will help raise awareness of the critical declines in pollinator and bee populations, and encourage the use of their work for educational purposes.
The authors add: "In this study, the authors provide a comprehensive source of online video material that offers a view of honey bee behavior within comb cells of a functioning colony. By providing a new mode of observation for the scientific community, beekeepers, and the general public the authors call attention to the general decline of insect biomass and diversity."
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Interview with author Dr Paul Siefert.
These Q&A may be quoted in media coverage; the questions should be attributed to PLOS and the answers to Dr Paul Siefert (Institut für Bienenkunde der Polytechnischen Gesellschaft Faculty Biological Sciences J.W. Goethe-University Frankfurt am Main).
PLOS: What first drew you to study honey bees and their behaviors?
Dr Siefert: During my studies at the Goethe-University Frankfurt I became interested in eusocial behavior after some practical work with squirrel monkeys. Eusocial behavior is the highest level of social organization and includes cooperative brood care, overlapping generations and division of labor. Interestingly, except for mammals only a few arthropods live eusocial, such as ants, termites and honey bees.
PLOS: What did you choose to investigate in this study, and why?
Siefert: In a previous project, my colleagues and I investigated the effects of insecticides on honey bee brood care within the colony, using long-term video recordings. Since there was high interest in my videos from developing bees within the comb cells in the scientific community and the public, I decided to publish further behavioral videos that were also recorded during this time. Our primary goal is to educate beekeepers and the public about the fascinating methods that bees have for organizing their colony.
PLOS: What are the key findings from your research?
Siefert: We were able to visualize behaviors within the comb cells, that are usually hidden from sight, and until recently, were primarily described through texts and line drawings, which lack the dynamics of moving images. This provides insight into worker behaviors, including the use of wax scales and existing nest material to remodel combs, storing pollen and nectar in cells, brood care and thermoregulation, and hygienic practices, such as cannibalism, grooming and surface cleaning.
PLOS: What most surprised or interested you about your findings?
Siefert: Generally, I am fascinated how honey bees are able to choose the beneficial decision for the colony, and wonder how they perceive their surroundings and information, and if their actions are based on learning or instinct. Specifically, I was surprised to see that the first of two workers, which successively entered the same cell that had parasites in it (the Varroa destructor mite), did not bother at all, but the next one attacked the mites vigorously.
PLOS: What do you hope your findings might lead to, and what are the next steps for your research?
Siefert: With our videos, we want to bring the processes of a fully functioning social insect colony into classrooms and homes, facilitating ecological awareness in modern times. We encourage the non-commercial use of our material to educate beekeepers, the media and the public and, in turn, call attention to the general decline of insect biomass and diversity. In the upcoming months I want to use the video method for research that requires the collection of precisely age-determined eggs.
Citation: Siefert P, Buling N, Grünewald B (2021) Honey bee behaviours within the hive: Insights from long-term video analysis. PLoS ONE 16(3): e0247323. https://doi.org/10.1371/journal.pone.0247323
Funding: We thank the European Union and Land Hessen (Germany) for funding this project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247323
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