Reduced cellular immune response in social insect lineages

Margarita Maria Lopez-Uribe, Warren B. Sconiers, Steven D. Frank, Robert R. Dunn, David R. Tarpy

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16 Scopus citations

Abstract

Social living poses challenges for individual fitness because of the increased risk of disease transmission among conspecifics. Despite this challenge, sociality is an evolutionarily successful lifestyle, occurring in the most abundant and diverse group of organisms on earth-the social insects. Two contrasting hypotheses predict the evolutionary consequences of sociality on immune systems. The social group hypothesis posits that sociality leads to stronger individual immune systems because of the higher risk of disease transmission in social species. By contrast, the relaxed selection hypothesis proposes that social species have evolved behavioural immune defences that lower disease risk within the group, resulting in lower immunity at the individual level. We tested these hypotheses bymeasuring the encapsulation response in 11 eusocial and non-eusocial insect lineages.We built phylogenetic mixed linear models to investigate the effect of behaviour, colony size and body size on cellular immune response. We found a significantly negative effect of colony size on encapsulation response (Markov chain Monte Carlo generalized linear mixed model (mcmcGLMM) p < 0.05; phylogenetic generalized least squares (PGLS) p < 0.05). Our findings suggest that insects living in large societies may rely more on behavioural mechanisms, such as hygienic behaviours, than on immune function to reduce the risk of disease transmission among nest-mates.

Original languageEnglish (US)
Article number0984
JournalBiology Letters
Volume12
Issue number3
DOIs
StatePublished - Mar 1 2016

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All Science Journal Classification (ASJC) codes

  • Agricultural and Biological Sciences (miscellaneous)
  • Agricultural and Biological Sciences(all)

Cite this

Lopez-Uribe, M. M., Sconiers, W. B., Frank, S. D., Dunn, R. R., & Tarpy, D. R. (2016). Reduced cellular immune response in social insect lineages. Biology Letters, 12(3), [0984]. https://doi.org/10.1098/rsbl.2015.0984