Behavioural biomechanics: leaf-cutter ant cutting behaviour depends on leaf edge geometry
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Leaf-cutter ants cut fresh leaves to grow a symbiotic fungus as crop. During cutting, one mandible is typically anchored onto the leaf lamina while the other slices through it like a knife. When initiating cuts into the leaf edge, however, foragers sometimes deviate from this behaviour and instead use their mandibles symmetrically, akin to scissors. In vivo behavioural assays revealed that the preference for either of the two cutting strategies depended on leaf edge geometry and differed between natural leaf margins that were straight or serrated with notch-like folds: leaf-cutter ants displayed a strong preference for scissor-cutting when leaf edges were straight or had wide notches. This preference, however, reversed in favour of knife-cutting when notches were narrow. To investigate whether this behavioural difference had a mechanical origin, we mimicked knife-cutting in ex vivo cutting experiments: for wide notches, all but the sharpest mandibles failed to initiate cuts, or only did so at large forces, caused by substantial leaf buckling and bending. This increased force demand would substantially limit the ability of foragers to cut leaves, and so reduce the colony’s access to food sources. Scissor-cutting may thus be an adaptation to the mechanical difficulties associated with bending and buckling of thin leaves.
Date Issued
2025-04-23
Date Acceptance
2025-02-06
Citation
Proceedings of the Royal Society of London. Biological Sciences, 2025, 292 (2045)
ISSN
0962-8452
Publisher
The Royal Society
Journal / Book Title
Proceedings of the Royal Society of London. Biological Sciences
Volume
292
Issue
2045
Copyright Statement
©2025 The Author(s). Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40262644
Subjects
ATTA
behavioural plasticity
Biology
CROP LOSSES
cutting forces
DIVISION-OF-LABOR
Ecology
Environmental Sciences & Ecology
Evolutionary Biology
FRACTURE
HYMENOPTERA
insect-plant interaction
leaf lamina
Life Sciences & Biomedicine
Life Sciences & Biomedicine - Other Topics
LOAD-SIZE SELECTION
MELANOPLUS-FEMURRUBRUM ORTHOPTERA
MORPHOLOGY
PHENOTYPIC PLASTICITY
PLANT DEFENSE
Science & Technology
sheet buckling
Publication Status
Published
Coverage Spatial
England
Article Number
20242926
Date Publish Online
2025-04-23