Insectes Sociaux

, Volume 60, Issue 2, pp 191–201 | Cite as

Colony-size effects on task organization in the harvester ant Pogonomyrmex californicus

  • C. T. Holbrook
  • T. H. Eriksson
  • R. P. Overson
  • J. Gadau
  • J. H. Fewell
Research Article


Colony size is a fundamental attribute of insect societies that appears to play an important role in their organization of work. In the harvester ant Pogonomyrmex californicus, division of labor increases with colony size during colony ontogeny and among unmanipulated colonies of the same age. However, the mechanism(s) integrating individual task specialization and colony size is unknown. To test whether the scaling of division of labor is an emergent epiphenomenon, as predicted by self-organizational models of task performance, we manipulated colony size in P. californicus and quantified short-term behavioral responses of individuals and colonies. Variation in colony size failed to elicit a change in division of labor, suggesting that colony-size effects on task specialization are mediated by slower developmental processes and/or correlates of colony size that were missing from our experiment. In contrast, the proportional allocation of workers to tasks shifted with colony size, suggesting that task needs or priorities depend, in part, on colony size alone. Finally, although task allocation was flexible, colony members differed consistently in task performance and spatial tendency across colony size treatments. Sources of interindividual behavioral variability include worker age and genotype (matriline).


Colony size Division of labor Social scaling Task allocation Task specialization 


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Copyright information

© International Union for the Study of Social Insects (IUSSI) 2013

Authors and Affiliations

  • C. T. Holbrook
    • 1
    • 2
  • T. H. Eriksson
    • 1
  • R. P. Overson
    • 1
  • J. Gadau
    • 1
  • J. H. Fewell
    • 1
  1. 1.School of Life Sciences and Center for Social Dynamics and ComplexityArizona State UniversityTempeUSA
  2. 2.Department of BiologyLynchburg CollegeLynchburgUSA

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