The honey bee stinger: An unusual pump with collapsible double pistons
- 1School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia
- 2School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
- 3Pollinator Futures Research Centre, Macquarie University, Sydney, NSW 2109, Australia
Abstract
Most stinging animals deliver venom by contracting muscles around a venom reservoir, but honey bees employ a fundamentally different strategy. The stingers of worker bees have the unique ability to autotomize, separating from the body, to continue to sting independently. Despite more than a century of anatomical descriptions, the mechanics of venom pumping have remained unresolved due to the challenges of observing them in action. We recorded high-speed videos of active, autotomized stingers, combined with micro computed tomography-based three-dimensional reconstruction to characterize the biomechanics of stinging in the honey bee Apis mellifera. We reveal that the stinger functions as a unique double-piston micro-pump. Two lancets, each possessing a deformable valve, slide in antiphase within a bulb chamber. These valves dynamically deform to alternately form a seal during the downstroke and collapse during the upstroke, enabling pressure generation for pumping while potentially minimizing backflow during refilling. The inverted tear-drop shape of the bulb facilitates refill even while pumping proceeds. We explored valve deformations and flow behavior by constructing a dynamically scaled physical model of the bulb chamber confirming key features of the pumping cycle and propose mechanisms for valve deformations. The double piston design adds significant design complexity but enables continuous venom delivery in a compact, autonomous unit. These findings provide deeper understanding of venom pumping in honey bees and other Hymenoptera. This study also provides evidence of an axial piston pump within a biological system and offers inspiration for the design of microfluidic pumping devices.
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BibTeX
@article{ramirezesquivel2026honey,
title = {{The honey bee stinger: An unusual pump with collapsible double pistons}},
author = {Fiorella Ramirez-Esquivel and Claudia Klose and Hyun Chai Lee and Quinn Graco and Ajay Narendra and Sridhar Ravi},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2026},
month = oct,
doi = {10.1073/pnas.2603916123},
url = {https://doi.org/10.1073/pnas.2603916123},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - The honey bee stinger: An unusual pump with collapsible double pistons
AU - Fiorella Ramirez-Esquivel
AU - Claudia Klose
AU - Hyun Chai Lee
AU - Quinn Graco
AU - Ajay Narendra
AU - Sridhar Ravi
PY - 2026
DA - 2026/10/12
JO - Proceedings of the National Academy of Sciences of the United States of America
DO - 10.1073/pnas.2603916123
UR - https://doi.org/10.1073/pnas.2603916123
AB - Most stinging animals deliver venom by contracting muscles around a venom reservoir, but honey bees employ a fundamentally different strategy. The stingers of worker bees have the unique ability to autotomize, separating from the body, to continue to sting independently. Despite more than a century of anatomical descriptions, the mechanics of venom pumping have remained unresolved due to the challenges of observing them in action. We recorded high-speed videos of active, autotomized stingers, combined with micro computed tomography-based three-dimensional reconstruction to characterize the biomechanics of stinging in the honey bee Apis mellifera. We reveal that the stinger functions as a unique double-piston micro-pump. Two lancets, each possessing a deformable valve, slide in antiphase within a bulb chamber. These valves dynamically deform to alternately form a seal during the downstroke and collapse during the upstroke, enabling pressure generation for pumping while potentially minimizing backflow during refilling. The inverted tear-drop shape of the bulb facilitates refill even while pumping proceeds. We explored valve deformations and flow behavior by constructing a dynamically scaled physical model of the bulb chamber confirming key features of the pumping cycle and propose mechanisms for valve deformations. The double piston design adds significant design complexity but enables continuous venom delivery in a compact, autonomous unit. These findings provide deeper understanding of venom pumping in honey bees and other Hymenoptera. This study also provides evidence of an axial piston pump within a biological system and offers inspiration for the design of microfluidic pumping devices.
SN - 0027-8424
SN - 1091-6490
ER -