Present address: Laboratoire Évolution, Génomes et Spéciation, CNRS, UPR 9034, 91198 Gif-sur-Yvette Cedex, France.
Reproductive system, social organization, human disturbance and ecological dominance in native populations of the little fire ant, Wasmannia auropunctata
Article first published online: 20 NOV 2009
© 2009 Blackwell Publishing Ltd
Volume 18, Issue 24, pages 5059–5073, December 2009
How to Cite
FOUCAUD, J., ORIVEL, J., FOURNIER, D., DELABIE, J. H. C., LOISEAU, A., LE BRETON, J., CERDAN, P. and ESTOUP, A. (2009), Reproductive system, social organization, human disturbance and ecological dominance in native populations of the little fire ant, Wasmannia auropunctata. Molecular Ecology, 18: 5059–5073. doi: 10.1111/j.1365-294X.2009.04440.x
- Issue published online: 16 DEC 2009
- Article first published online: 20 NOV 2009
- Received 3 June 2009; revision received 12 October 2009; accepted 19 October 2009
- biological invasion;
- human disturbance;
- social organization;
- Wasmannia auropunctata
The invasive ant species Wasmannia auropunctata displays both ecologically dominant and non-dominant populations within its native range. Three factors could theoretically explain the ecological dominance of some native populations of W. auropunctata: (i) its clonal reproductive system, through demographic and/or adaptive advantages; (ii) its unicolonial social organization, through lower intraspecific and efficient interspecific competition; (iii) the human disturbance of its native range, through the modification of biotic and abiotic environmental conditions. We used microsatellite markers and behavioural tests to uncover the reproductive modes and social organization of dominant and non-dominant native populations in natural and human-modified habitats. Microsatellite and mtDNA data indicated that dominant and non-dominant native populations (supercolonies as determined by aggression tests) of W. auropunctata did not belong to different evolutionary units. We found that the reproductive system and the social organization are neither necessary nor sufficient to explain W. auropunctata ecological dominance. Dominance rather seems to be set off by unknown ecological factors altered by human activities, as all dominant populations were recorded in human-modified habitats. The clonal reproductive system found in some populations of W. auropunctata may however indirectly contribute to its ecological dominance by allowing the species to expand its environmental niche, through the fixation over time of specific combinations of divergent male and female genotypes. Unicoloniality may rather promote the range expansion of already dominant populations than actually trigger ecological dominance. The W. auropunctata model illustrates the strong impact of human disturbance on species’ ecological features and the adaptive potential of clonal reproductive systems.