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Journal of Insect Behavior

, Volume 30, Issue 1, pp 130–137 | Cite as

Sex Ratios in a Socially Parasitic Bee and Implications for Host-Parasite Interactions

  • Nahid Shokri Bousjein
  • Morgan Staines
  • Cathy Vo
  • Natalie Puiu
  • Carmen R. B. da Silva
  • Jack Harrington
  • Sara Wilkinson
  • Kelly Pratt
  • Michael P. Schwarz
Article

Abstract

Obligate social parasites of Hymenoptera, known as inquilines, have received enormous attention due to the elaborate adaptations they exhibit for exploiting their hosts, and because they have frequently been used to infer sympatric speciation. Their population biology can be difficult to infer as they are both rare and difficult to extract from host nests. Sex allocation has been studied for very few inquilines of social Hymenoptera. Here we report sex ratio patterns in the allodapine bee Inquilina schwarzi, which is an obligate social parasite of another allodapine, Exoneura robusta. We show that the sex ratio of this inquiline varies with its brood number, it is female-biased in the smallest broods, but becomes more even in larger broods, where the population-wide sex ratio is close to parity. We argue that this pattern of bias is consistent with local resource competition, where inquiline females compete to inherit their natal colony. We also argue that extremely female-biased sex ratios of the host species, combined with overall sex ratio parity in the parasite, may help ameliorate disparity in effective population sizes between these two species which are locked in an evolutionary arms race.

Keywords

Bees effective population size inquilines local resource competition sex ratio social parasites 

Notes

Acknowledgements

We thank Meg Schwarz and Mohammad Javidkar for help with field collections. We also thank the Holsworth Wildlife Trust for supporting field work by Shokri Bousjein.

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Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  • Nahid Shokri Bousjein
    • 1
  • Morgan Staines
    • 1
  • Cathy Vo
    • 1
  • Natalie Puiu
    • 1
  • Carmen R. B. da Silva
    • 1
    • 2
  • Jack Harrington
    • 1
  • Sara Wilkinson
    • 1
  • Kelly Pratt
    • 1
  • Michael P. Schwarz
    • 1
  1. 1.Biological SciencesFlinders UniversityAdelaideAustralia
  2. 2.School of Biological SciencesUniversity of QueenslandSt LuciaAustralia

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