Present address: Projekt Management Jülich, Division BIO, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Global-scale analyses of chemical ecology and population genetics in the invasive Argentine ant
Article first published online: 21 JAN 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd
Volume 18, Issue 5, pages 997–1005, March 2009
How to Cite
BRANDT, M., VAN WILGENBURG, E. and TSUTSUI, N. D. (2009), Global-scale analyses of chemical ecology and population genetics in the invasive Argentine ant. Molecular Ecology, 18: 997–1005. doi: 10.1111/j.1365-294X.2008.04056.x
- Issue published online: 18 FEB 2009
- Article first published online: 21 JAN 2009
- Received 19 August 2008; revision revised 12 November 2008; accepted 27 November 2008
- chemical ecology;
- cuticular hydrocarbon;
- invasive species;
- nestmate recognition;
- population genetics
Ants are some of the most abundant and ecologically successful terrestrial organisms, and invasive ants rank among the most damaging invasive species. The Argentine ant is a particularly well-studied invader, in part because of the extreme social structure of introduced populations, known as unicoloniality. Unicolonial ants form geographically vast supercolonies, within which territorial behaviour and intraspecific aggression are absent. Because the extreme social structure of introduced populations arises from the widespread acceptance of conspecifics, understanding how this colonymate recognition occurs is key to explaining their success as invaders. Here, we present analyses of Argentine ant recognition cues (cuticular hydrocarbons) and population genetic characteristics from 25 sites across four continents and the Hawaiian Islands. By examining both hydrocarbon profiles and microsatellite genotypes in the same individual ants, we show that native and introduced populations differ in several respects. Both individual workers and groups of nestmates in the introduced range possess less diverse chemical profiles than ants in the native range. As previous studies have reported, we also find that introduced populations possess much lower levels of genetic diversity than populations in the native range. Interestingly, the largest supercolonies on several continents are strikingly similar to each other, suggesting that they arose from a shared introduction pathway. This high similarity suggests that these geographically far-flung ants may still recognize and accept each other as colonymates, thus representing distant nodes of a single, widely distributed supercolony. These findings shed light on the behaviour and sociality of these unicolonial invaders, and pose new questions about the history and origins of introduced populations.