Publications des scientifiques de l'IRD

Orivel J., Malé P. J., Lauth J., Roux Olivier, Petitclerc F., Dejean A., Leroy Céline. (2017). Trade-offs in an ant - plant - fungus mutualism. Proceedings of the Royal Society B : Biological Sciences, 284 (1850), p. art. 20161679 [10 p.]. ISSN 0962-8452.

Titre du document
Trade-offs in an ant - plant - fungus mutualism
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000397883100002
Auteurs
Orivel J., Malé P. J., Lauth J., Roux Olivier, Petitclerc F., Dejean A., Leroy Céline
Source
Proceedings of the Royal Society B : Biological Sciences, 2017, 284 (1850), p. art. 20161679 [10 p.] ISSN 0962-8452
Species engaged in multiple, simultaneous mutualisms are subject to tradeoffs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du monde animal [080] ; Etudes, transformation, conservation du milieu naturel [082]
Description Géographique
GUYANE FRANCAISE
Localisation
Fonds IRD [F B010069441]
Identifiant IRD
fdi:010069441
Contact