TY - JOUR
T1 - Changes in the cuticular hydrocarbons of incipient reproductives correlate with triggering of worker policing in the bulldog ant Myrmecia gulosa
AU - Dietemann, Vincent
AU - Liebig, Jürgen
AU - Hölldobler, Bert
AU - Peeters, Christian
N1 - Funding Information:
Acknowledgements We are grateful to Michael Schwarz, Katja Hogendoorn, Remko Leijs, Steve Shattuck, Archie McArthur and Russell for their hospitality and assistance during fieldwork. Ben Oldroyd, Thibaud Monnin, Liselotte Sundström and three anonymous referees gave valuable criticisms on earlier drafts. This work was funded by the Deutsche Forschungsgemeinschaft SFB 554 (C3) and the Graduiertenkolleg ‘Grundlagen des Arthropodenverhaltens’. The experiments comply with the current laws of Germany. The ants were collected under scientific investigation license A2247 issued by National Parks and Wildlife Service of New South Wales, and exported under permits PWS P993042 and PWS 20002478 issued by Environment Australia.
PY - 2005/9
Y1 - 2005/9
N2 - In social insects, conflicts over male parentage can be resolved by worker policing. However, the evolution of policing behavior is constrained by the ability of individuals to identify reproductive nestmates, or their eggs. We investigated the occurrence of worker policing and its underlying chemical communication in the bulldog ant Myrmecia gulosa. Although workers have functional ovaries and can lay male-destined eggs, they do not reproduce in queenright colonies. To determine if their sterility is a consequence of worker policing, we experimentally induced worker reproduction in the presence of a queen. Some individuals were seized and immobilized by nestmates, and sometimes killed as a consequence. Although the ovarian development of immobilized individuals was variable, their cuticular hydrocarbon profiles were intermediate between reproductive and nonreproductive workers, indicating they were in the process of starting to reproduce. Approximately 29% of these incipient reproductive workers were successfully policed. To test for policing on eggs, we transferred viable worker eggs to queenright colonies and monitored their acceptance. Furthermore, we compared the surface hydrocarbons of the different types of eggs to determine whether these chemicals could be involved in egg recognition. We found that although there were differences in hydrocarbon profiles and discrimination between queen and worker-laid eggs, viable eggs were not destroyed. Our results strongly support the idea that cuticular hydrocarbons are involved in the policing of reproductive workers. A low level of worker policing appears sufficient to select for self-restraint in workers when few fitness benefits are gained by selfish reproduction. Policing of eggs may thus be unnecessary.
AB - In social insects, conflicts over male parentage can be resolved by worker policing. However, the evolution of policing behavior is constrained by the ability of individuals to identify reproductive nestmates, or their eggs. We investigated the occurrence of worker policing and its underlying chemical communication in the bulldog ant Myrmecia gulosa. Although workers have functional ovaries and can lay male-destined eggs, they do not reproduce in queenright colonies. To determine if their sterility is a consequence of worker policing, we experimentally induced worker reproduction in the presence of a queen. Some individuals were seized and immobilized by nestmates, and sometimes killed as a consequence. Although the ovarian development of immobilized individuals was variable, their cuticular hydrocarbon profiles were intermediate between reproductive and nonreproductive workers, indicating they were in the process of starting to reproduce. Approximately 29% of these incipient reproductive workers were successfully policed. To test for policing on eggs, we transferred viable worker eggs to queenright colonies and monitored their acceptance. Furthermore, we compared the surface hydrocarbons of the different types of eggs to determine whether these chemicals could be involved in egg recognition. We found that although there were differences in hydrocarbon profiles and discrimination between queen and worker-laid eggs, viable eggs were not destroyed. Our results strongly support the idea that cuticular hydrocarbons are involved in the policing of reproductive workers. A low level of worker policing appears sufficient to select for self-restraint in workers when few fitness benefits are gained by selfish reproduction. Policing of eggs may thus be unnecessary.
KW - Aggression
KW - Cuticular hydrocarbons
KW - Oophagy
KW - Worker policing
KW - Worker reproduction
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U2 - 10.1007/s00265-005-0939-1
DO - 10.1007/s00265-005-0939-1
M3 - Article
AN - SCOPUS:27744505837
SN - 0340-5443
VL - 58
SP - 486
EP - 496
JO - Behavioral Ecology and Sociobiology
JF - Behavioral Ecology and Sociobiology
IS - 5
ER -