Department of Entomology
  • About
    • At a Glance
    • Welcome
    • Code of Conduct
    • Diversity, Equity, and Inclusion >
      • DEI Working Group
      • Resources
    • Departmental History
    • For Alumni
    • Support Entomology >
      • Steinhauer Scholarship Fund
    • Contact >
      • Directions
  • News
    • News
    • Seminar Blog
    • Seminar Schedule
    • Awards
  • People
    • Faculty
    • Post Docs
    • Students
    • Staff
    • Alumni
    • For PI/Faculty
    • Proposal Resources
  • Academics
    • Graduate >
      • Admissions
      • MS Degree Requirements
      • PhD Degree Requirements
      • Graduate Student Resources
      • Forms for Grad Students
      • Financial Assistance
      • Award & Funding Opportunities
      • Entomology Student Organization
    • Online Masters in Applied Entomology
    • Undergraduate >
      • Entomology Minor
      • Honors Program
  • Research
    • IPM & Biological Control of Agricultural, Urban & Forest Pests
    • Ecology, Conservation, Restoration, Climate Change >
      • Pollinator Science and Apiculture
    • Evolution, Systematics and Evo-Devo
    • Genetics & Genomics and Medical Entomology
  • Extension/Outreach
    • Educational Outreach
    • Insect Camp
    • Insect Drawings
    • Insect Identification
    • Pesticide Education and Assessment Program
    • Plant Diagnostic Laboratory (PDL)

Age is in the guts: Estimating honey bee age and how it relates to colony mortality

5/11/2023

 
​When you see a honey bee buzzing around, or while you spread honey on your toast, have you ever wondered how old the honey bees that are visiting flowers or making honey are? The answer is: it depends. Worker honey bees assume different jobs in their life, and that role changes with age. Young workers take care of the colony, nursing and feeding the larvae. Later they become guards, protecting the hive. When the worker bee is even older, they take on the job of exploring the outdoors and foraging nectar and pollen for the colony. So, a bee pollinating a flower is probably older than the bee that made your honey. 
graphFigure 1. Caged bees with lower lifespan produce less honey. “Median lifespan of caged bees, either mean observed or model estimated per year vs mean honey” (Nearman & vanEngelsdorp 2022).
​However, these roles can switch depending on the needs of the colony. In spring, when colony population is growing, if there are too few bees at the age of foraging, younger bees will advance to this role faster. The same happens if there are too few young bees, older bees will take on the role of nursing.  These shifts in age and numbers can be related to the health and mortality of the whole colony. Detecting shifts in age in the colonies can help predict the overall health of the colony. But how can we use these shifts to understand the lifespan of a colony?

​In his exit seminar, the UMD Entomology alum Dr. Anthony Nearman talked about his Ph.D. research in the vanEngelsdorp Bee Lab investigating mortality and colony lifespan prediction tools. Anthony performed laboratory caged studies to first look at how the bees react to different supplements of water and resources. He showed that bees that have access to water have a longer lifespan. To investigate what other variables apart from water availability could drive colony mortality, Anthony modelled populations using BEEHAVE, an internationally used modeling tool that simulates how colonies would react to different stressors. The models predicted that colonies with lower average bee life spans have lower success, producing less honey (Nearman & vanEngelsdorp 2022). So, the longer the bees live, the more a colony can thrive.

​But how can we tell how old the bees in the colony are? On the outside, worker bees look really similar, so it would be hard to say just by looking at them. But are worker bees all the same on the inside? Anthony further investigated if worker bee behavior and internal anatomy can clue us in on their age.  
bee malpighian tubulesFigure 2. Older honey bees have more and clearer Malpighian tubules. Malpighian tubules in honey bees age 30 (A) and 3 days (B).
Previous work in the lab showed that some traits in a bee’s anatomy could be age-dependent (vanEngelsdorp et al 2017). But can any of these traits measure the age demography and predict bee colony mortality? To answer this, Anthony observed traits mostly in the abdomen of bees from different ages, reared in cages and in colonies across seasons. To measure age, traits should change in prevalence over time, show large enough differences to be detected, while being consistent across rearing environments and seasons. He found four traits that met all the criteria: hypopharyngeal gland development, Malpighian tubule quantity, rectum color, and rectum size. For instance, older bees have many more Malpighian tubules than younger bees. This demonstrates that while the bees may visually look the same to us, their internal anatomy and physiology could be different.

​Can these individual age-dependent changes be extrapolated to the lifespan of a whole colony when faced with risk factors such as Varroa mite infestation? Anthony compared the physiology of bees from healthy colonies and colonies infested by mites, which might perish over the winter season. He sampled those colonies in September for three years and found that if a colony has too many older bees before the winter, there is a lower chance of survival. This research presents potential methods to estimate the age of honey bees and sets the groundwork for studies in controlled environments. ​​

Author: Taís Ribeiro is a PhD student in the EspíndoLab working on the ecology and evolution of South American oil-collecting bees from the genus Chalepogenus.

References
VanEngelsdorp, D., Traynor, K. S., Andree, M., Lichtenberg, E. M., Chen, Y., Saegerman, C., & Cox-Foster, D. L. (2017). Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology. PLoS One, 12(7), e0179535. https://doi.org/10.1371/journal.pone.0179535

Nearman, A., & VanEngelsdorp, D. (2022). Water provisioning increases caged worker bee lifespan and caged worker bees are living half as long as observed 50 years ago. Scientific Reports, 12(1), 18660. https://doi.org/10.1038/s41598-022-21401-

Comments are closed.

    Categories

    All
    Awards
    Colloquium
    Faculty Spotlight
    Fall 2013 Colloquium
    Fall 2014 Colloquium
    Fall 2015 Colloquium
    Fall 2016 Colloquium
    Featured
    Innovation
    News
    Publications
    Science Projects
    SESYNC
    Spring 2014 Colloquium
    Spring 2015 Colloquium
    Spring 2016 Colloquium
    Talks
    Undergraduate

    Archives

    April 2025
    March 2025
    February 2025
    December 2024
    November 2024
    October 2024
    June 2024
    May 2024
    April 2024
    March 2024
    December 2023
    November 2023
    October 2023
    September 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    March 2023
    February 2023
    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    December 2017
    November 2017
    October 2017
    September 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013

    RSS Feed

Picture
Picture
Picture
Department of Entomology 
University of Maryland 
4112 Plant Sciences Building 
College Park, MD 20742-4454
USA

Telephone: 301.405.3911 
Fax: 301.314.9290
Picture
Web Accessibility
  • About
    • At a Glance
    • Welcome
    • Code of Conduct
    • Diversity, Equity, and Inclusion >
      • DEI Working Group
      • Resources
    • Departmental History
    • For Alumni
    • Support Entomology >
      • Steinhauer Scholarship Fund
    • Contact >
      • Directions
  • News
    • News
    • Seminar Blog
    • Seminar Schedule
    • Awards
  • People
    • Faculty
    • Post Docs
    • Students
    • Staff
    • Alumni
    • For PI/Faculty
    • Proposal Resources
  • Academics
    • Graduate >
      • Admissions
      • MS Degree Requirements
      • PhD Degree Requirements
      • Graduate Student Resources
      • Forms for Grad Students
      • Financial Assistance
      • Award & Funding Opportunities
      • Entomology Student Organization
    • Online Masters in Applied Entomology
    • Undergraduate >
      • Entomology Minor
      • Honors Program
  • Research
    • IPM & Biological Control of Agricultural, Urban & Forest Pests
    • Ecology, Conservation, Restoration, Climate Change >
      • Pollinator Science and Apiculture
    • Evolution, Systematics and Evo-Devo
    • Genetics & Genomics and Medical Entomology
  • Extension/Outreach
    • Educational Outreach
    • Insect Camp
    • Insect Drawings
    • Insect Identification
    • Pesticide Education and Assessment Program
    • Plant Diagnostic Laboratory (PDL)