title: Plant-ants use symbiotic fungi as a food source: new insight into the nutritional ecology of ant-plant interactions.
abstract: Usually studied as pairwise interactions, mutualisms often involve networks of interacting species. Numerous tropical arboreal ants are specialist inhabitants of myrmecophytes (plants bearing domatia, i.e. hollow structures specialized to host ants) and are thought to rely almost exclusively on resources derived from the host plant. Recent studies, following up on century-old reports, have shown that fungi of the ascomycete order Chaetothyriales live in symbiosis with plant-ants within domatia. We tested the hypothesis that ants use domatia-inhabiting fungi as food in three ant-plant symbioses: Petalomyrmex phylax/Leonardoxa africana, Tetraponera aethiops/Barteria fistulosa and Pseudomyrmex penetrator/Tachigali sp. Labelling domatia fungal patches in the field with either a fluorescent dye or (15)N showed that larvae ingested domatia fungi. Furthermore, when the natural fungal patch was replaced with a piece of a (15)N-labelled pure culture of either of two Chaetothyriales strains isolated from T. aethiops colonies, these fungi were also consumed. These two fungi often co-occur in the same ant colony. Interestingly, T. aethiops workers and larvae ingested preferentially one of the two strains. Our results add a new piece in the puzzle of the nutritional ecology of plant-ants.
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175, CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 5, France. rumsais.blatrix@cefe.cnrs.fr
authors.forename: Rumsaïs
authors.initials: R
authors.lastname: Blatrix
authors.forename: Champlain
authors.initials: C
authors.lastname: Djiéto-Lordon
authors.forename: Laurence
authors.initials: L
authors.lastname: Mondolot
authors.forename: Philippe
authors.initials: P
authors.lastname: La Fisca
authors.forename: Hermann
authors.initials: H
authors.lastname: Voglmayr
authors.forename: Doyle
authors.initials: D
authors.lastname: McKey
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D001203:Ascomycota / Q000502:physiology*; D001557:Benzenesulfonates / Q000737:chemistry; D002163:Cameroon; D007887:Fabaceae / Q000502:physiology*; D005247:Feeding Behavior; D005616:French Guiana; D009587:Nitrogen Isotopes / Q000737:chemistry; D031683:Passifloraceae / Q000502:physiology*; D013559:Symbiosis
chemical_list: D001557:Benzenesulfonates; D009587:Nitrogen Isotopes; C007061:C.I. Fluorescent Brightening Agent 28