Behavioral Ecology and Sociobiology

, Volume 58, Issue 6, pp 527–533 | Cite as

Dual mechanism of queen influence over sex ratio in the ant Pheidole pallidula

  • Ludivine de Menten
  • Denis FournierEmail author
  • Colin Brent
  • Luc Passera
  • Edward L. Vargo
  • Serge Aron
Original Article


Social Hymenoptera are general models for the study of parent-offspring conflict over sex ratio, because queens and workers frequently have different reproductive optima. The ant Pheidole pallidula shows a split distribution of sex ratios with most of the colonies producing reproductives of a single sex. Sex ratio specialization is tightly associated with the breeding system, with single-queen (monogynous) colonies producing male-biased brood and multiple-queen (polygynous) colonies female-biased brood. Here, we show that this sex specialization is primarily determined by the queen’s influence over colony sex ratio. Queens from monogynous colonies produce a significantly more male-biased primary sex ratio than queens from polygynous colonies. Moreover, queens from monogynous colonies produce a significantly lower proportion of diploid eggs that develop into queens and this is associated with lower rate of juvenile hormone (JH) production compared to queens from polygynous colonies. These results indicate that queens regulate colony sex ratio in two complementary ways: by determining the proportion of female eggs laid and by hormonally biasing the development of female eggs into either a worker or reproductive form. This is the first time that such a dual system of queen influence over colony sex ratio is identified in an ant.


Conflicts Juvenile hormone Kin selection Microsatellites Primary sex ratio Social hymenoptera Split sex ratio 



We thank M. Gilbert, K. Helms and Y. Roisin, T. Wenseleers, two anonymous reviewers and the associate editor for their comments on the manuscript. Thanks also to C. Schal for guidance and use of lab facilities for endocrine analyses. Financial support was provided by the FRIA (LM), the Fonds Van Buuren and the Fondation de Meurs-François (DF), and the Belgian National Fund for Scientific Research (FNRS) for personal support (Senior Research Associate position) and several grants (SA). The authors declare that the experiments comply with the Belgian, French and American current laws. First three authors are contributed equally to this work


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Ludivine de Menten
    • 1
  • Denis Fournier
    • 1
    Email author
  • Colin Brent
    • 2
  • Luc Passera
    • 3
  • Edward L. Vargo
    • 2
  • Serge Aron
    • 1
  1. 1.Behavioral and Evolutionary EcologyUniversité Libre de Bruxelles CP 160/12BrusselsBelgium
  2. 2.Department of EntomologyNorth Carolina State UniversityRaleighUSA
  3. 3.Centre de Recherches sur la Cognition AnimaleCNRS-Université Paul SabatierToulouseFrance

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