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Milligan PD, Martin TA, Pringle EG, Prior KM, Palmer TM. Symbiotic ant traits produce differential host-plant carbon and water dynamics in a multi-species mutualism. Ecology 2023; 104:e3880. [PMID: 36199213 DOI: 10.1002/ecy.3880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/28/2022] [Accepted: 07/28/2022] [Indexed: 02/01/2023]
Abstract
Cooperative interactions may frequently be reinforced by "partner fidelity feedback," in which high- or low-quality partners drive positive feedbacks with high or low benefits for the host, respectively. Benefits of plant-animal mutualisms for plants have been quantified almost universally in terms of growth or reproduction, but these are only two of many sinks to which a host-plant allocates its resources. By investigating how partners to host-plants impact two fundamental plant resources, carbon and water, we can better characterize plant-partner fidelity and understand how plant-partner mutualisms may be modulated by resource dynamics. In Laikipia, Kenya, four ant species compete for Acacia drepanolobium host-plants. These ants differ in multiple traits, from nectar consumption to host-plant protection. Using a 5-year ant removal experiment, we compared carbon fixation, leaf water status, and stem non-structural carbohydrate concentrations for adult ant-plants with and without ant partners. Removal treatments showed that the ants differentially mediate tree carbon and/or water resources. All three ant species known to be aggressive against herbivores were linked to benefits for host-plant resources, but only the two species that defend but do not prune the host, Crematogaster mimosae and Tetraponera penzigi, increased tree carbon fixation. Of these two species, only the nectivore C. mimosae increased tree simple sugars. Crematogaster nigriceps, which defends the tree but also castrates flowers and prunes meristems, was linked only to lower tree water stress approximated by pre-dawn leaf water potential. In contrast to those defensive ants, Crematogaster sjostedti, a poor defender that displaces other ants, was linked to lower tree carbon fixation. Comparing the effects of the four ant species across control trees suggests that differential ant occupancy drives substantial differences in carbon and water supply among host trees. Our results highlight that ant partners can positively or negatively impact carbon and/or water relations for their host-plant, and we discuss the likelihood that carbon- and water-related partner fidelity feedback loops occur across ant-plant mutualisms.
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Affiliation(s)
- Patrick D Milligan
- Department of Biology, University of Florida, Gainesville, Florida, USA.,Mpala Research Centre, Nanyuki, Kenya.,Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Reno, Nevada, USA
| | - Timothy A Martin
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, USA
| | - Elizabeth G Pringle
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Reno, Nevada, USA
| | - Kirsten M Prior
- Department of Biology, SUNY Binghamton, Binghamton, New York, USA
| | - Todd M Palmer
- Department of Biology, University of Florida, Gainesville, Florida, USA.,Mpala Research Centre, Nanyuki, Kenya
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2
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Villamil N, Boege K, Stone GN. Defensive mutualists affect outcross pollen transfer and male fitness in their host plant. OIKOS 2022. [DOI: 10.1111/oik.08788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Nora Villamil
- Inst. of Evolutionary Biology, Univ. of Edinburgh, Ashworth Laboratories, The King's Buildings Edinburgh UK
- Dept of Ecology and Evolution, Univ. de Lausanne Biophore Lausanne Switzerland
| | - Karina Boege
- Inst. de Ecología, Univ. Nacional Autónoma de México, Ciudad Universitaria Ciudad De México México
| | - Graham N. Stone
- Inst. of Evolutionary Biology, Univ. of Edinburgh, Ashworth Laboratories, The King's Buildings Edinburgh UK
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3
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Villamil N, Boege K, Stone GN. Testing the Distraction Hypothesis: Do extrafloral nectaries reduce ant-pollinator conflict? THE JOURNAL OF ECOLOGY 2019; 107:1377-1391. [PMID: 31217634 PMCID: PMC6559321 DOI: 10.1111/1365-2745.13135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Ant guards protect plants from herbivores, but can also hinder pollination by damaging reproductive structures and/or repelling pollinators. Natural selection should favour the evolution of plant traits that deter ants from visiting flowers during anthesis, without waiving their defensive services. The Distraction Hypothesis posits that rewarding ants with extrafloral nectar could reduce their visitation of flowers, reducing ant-pollinator conflict while retaining protection of other structures.We characterised the proportion of flowers occupied by ants and the number of ants per flower in a Mexican ant-plant, Turnera velutina. We clogged extrafloral nectaries on field plants and observed the effects on patrolling ants, pollinators and ants inside flowers, and quantified the effects on plant fitness. Based on the Distraction Hypothesis, we predicted that preventing extrafloral nectar secretion should result in fewer ants active at extrafloral nectaries, more ants inside flowers and a higher proportion of flowers occupied by ants, leading to ant-pollinator conflict, with reduced pollinator visitation and reduced plant fitness.Overall ant activity inside flowers was low. Preventing extrafloral nectar secretion through clogging reduced the number of ants patrolling extrafloral nectaries, significantly increased the proportion of flowers occupied by ants from 6.1% to 9.7%, and reduced plant reproductive output through a 12% increase in the probability of fruit abortion. No change in the numbers of ants or pollinators inside flowers was observed. This is the first support for the Distraction Hypothesis obtained under field conditions, showing ecological and plant fitness benefits of the distracting function of extrafloral nectar during anthesis. Synthesis. Our study provides the first field experimental support for the Distraction Hypothesis, suggesting that extrafloral nectaries located close to flowers may bribe ants away from reproductive structures during the crucial pollination period, reducing the probability of ant occupation of flowers, reducing ant-pollinator conflict and increasing plant reproductive success.
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Affiliation(s)
- Nora Villamil
- Ashworth Laboratories, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghUK
| | - Karina Boege
- Instituto de Ecología, Departamento de Ecología EvolutivaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Graham N. Stone
- Ashworth Laboratories, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghUK
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4
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Gibert A, Tozer W, Westoby M. Plant performance response to eight different types of symbiosis. THE NEW PHYTOLOGIST 2019; 222:526-542. [PMID: 30697746 DOI: 10.1111/nph.15392] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/07/2018] [Indexed: 06/09/2023]
Abstract
Almost all plant species interact with one or more symbioses somewhere within their distribution range. Bringing together plant trait data and growth responses to symbioses spanning 552 plant species, we provide for the first time on a large scale (597 studies) a quantitative synthesis on plant performance differences between eight major types of symbiosis, including mycorrhizas, N-fixing bacteria, fungal endophytes and ant-plant interactions. Frequency distributions of plant growth responses varied considerably between different types of symbiosis, in terms of both mean effect and 'risk', defined here as percentage of experiments reporting a negative effect of symbiosis on plants. Contrary to expectation, plant traits were poor predictors of growth response across and within all eight symbiotic associations. Our analysis showed no systematic additive effect when a host plant engaged in two functionally different symbioses. This synthesis suggests that plant species' ecological strategies have little effect in determining the influence of a symbiosis on host plant growth. Reliable quantification of differences in plant performance across symbioses will prove valuable for developing general hypotheses on how species become engaged in mutualisms without a guarantee of net returns.
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Affiliation(s)
- Anais Gibert
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Wade Tozer
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Mark Westoby
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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5
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Villamil N, Boege K, Stone GN. Ant-Pollinator Conflict Results in Pollinator Deterrence but no Nectar Trade-Offs. FRONTIERS IN PLANT SCIENCE 2018; 9:1093. [PMID: 30154806 PMCID: PMC6102506 DOI: 10.3389/fpls.2018.01093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
Direct and indirect negative interactions between ant guards and pollinators on ant-plants are expected for two reasons. First, aggressive ants may deter pollinators directly. Second, pollinators benefit from plant investment in reproduction whilst ants benefit from plant investment in indirect defense, and resource allocation trade-offs between these functions could lead to indirect conflict. We explored the potential for ant-pollinator conflict in a Mexican myrmecophile, Turnera velutina, which rewards ants with extrafloral nectar and pollinators with floral nectar. We characterized the daily timing of ant and pollinator activity on the plant and used experiments to test for direct and indirect conflict between these two groups of mutualists. We tested for direct conflict by quantifying pollinator responses to flowers containing dead specimens of aggressive ant species, relative to unoccupied control flowers. We assessed indirect conflict by testing for the existence of a trade-off in sugar allocation between ant and pollinator rewards, evidenced by an increase in floral nectar secretion when extrafloral nectar secretion was prevented. Secretion of floral and extrafloral nectar, activity of ants and pollinators, and pollen deposition all overlapped in daily time and peaked within the first 2 h after flowers opened. We found evidence of direct conflict, in that presence of ants inside the flowers altered pollinator behavior and reduced visit duration, although visit frequency was unchanged. We found no evidence for indirect conflict, with no significant difference in the volume or sugar content of floral nectar between control plants and those in which extrafloral nectar secretion was prevented. The presence of ants in flowers alters pollinator behavior in ways that are likely to affect pollination dynamics, though there is no apparent trade-off between plant investment in nectar rewards for pollinators and ant guards. Further studies are required to quantify the effect of the natural abundance of ants in flowers on pollinator behavior, and any associated impacts on plant reproductive success.
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Affiliation(s)
- Nora Villamil
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Karina Boege
- Instituto de Ecología, Departamento de Ecología Evolutiva, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Graham N. Stone
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
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6
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Dejean A, Azémar F, Petitclerc F, Delabie JHC, Corbara B, Leroy C, Céréghino R, Compin A. Highly modular pattern in ant-plant interactions involving specialized and non-specialized myrmecophytes. Naturwissenschaften 2018; 105:43. [PMID: 29951968 DOI: 10.1007/s00114-018-1570-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 11/28/2022]
Abstract
Because Tachia guianensis (Gentianaceae) is a "non-specialized myrmecophyte" associated with 37 ant species, we aimed to determine if its presence alters the ant guild associated with sympatric "specialized myrmecophytes" (i.e., plants sheltering a few ant species in hollow structures). The study was conducted in a hilly zone of a neotropical rainforest where two specialized myrmecophytes grow at the bottom of the slopes, another at mid-slope, and a fourth on the hilltops. Tachia guianensis, which occurred everywhere, had its own guild of associated ant species. A network analysis showed that its connections with the four other myrmecophytes were rare and weak, the whole resulting in a highly modular pattern of interactions with one module (i.e., subnetwork) per myrmecophyte. Three ant species parasitized three out of the four specialized myrmecophytes (low nestedness noted), but were not or barely associated with T. guianensis that therefore did not influence the parasitism of specialized myrmecophytes.
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Affiliation(s)
- Alain Dejean
- UPS-ECOLAB, CNRS, Université de Toulouse, 118 route de Narbonne, 31062, Toulouse, France.
- CNRS, UMR EcoFoG, AgroParisTech, Cirad, INRA, Université des Antilles, Université de Guyane, 97310, Kourou, France.
| | - Frédéric Azémar
- UPS-ECOLAB, CNRS, Université de Toulouse, 118 route de Narbonne, 31062, Toulouse, France
| | - Frédéric Petitclerc
- CNRS, UMR EcoFoG, AgroParisTech, Cirad, INRA, Université des Antilles, Université de Guyane, 97310, Kourou, France
| | - Jacques H C Delabie
- Laboratório de Mirmecologia, CEPEC-CEPLAC, Itabuna, Bahia, 45600-970, Brazil
- UESC-DCAA, Ilhéus, Bahia, 45662-900, Brazil
| | - Bruno Corbara
- CNRS, LMGE, Université Clermont Auvergne, F-63000, Clermont-Ferrand, France
| | - Céline Leroy
- AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Montpellier, France
| | - Régis Céréghino
- UPS-ECOLAB, CNRS, Université de Toulouse, 118 route de Narbonne, 31062, Toulouse, France
| | - Arthur Compin
- UPS-ECOLAB, CNRS, Université de Toulouse, 118 route de Narbonne, 31062, Toulouse, France
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7
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Orivel J, Malé PJ, Lauth J, Roux O, Petitclerc F, Dejean A, Leroy C. Trade-offs in an ant-plant-fungus mutualism. Proc Biol Sci 2018; 284:rspb.2016.1679. [PMID: 28298342 DOI: 10.1098/rspb.2016.1679] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 08/31/2016] [Indexed: 11/12/2022] Open
Abstract
Species engaged in multiple, simultaneous mutualisms are subject to trade-offs 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.
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Affiliation(s)
- Jérôme Orivel
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Pierre-Jean Malé
- UMR Evolution et Diversité Biologique, Université de Toulouse, 118 Route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Jérémie Lauth
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Olivier Roux
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Frédéric Petitclerc
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Alain Dejean
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France.,Ecolab, Université de Toulouse, CNRS, INPT, UPS, 118 Route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Céline Leroy
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France.,IRD, UMR AMAP (botAnique et Modélisation de l'Architecture des Plantes et des Végétations), Boulevard de la Lironde, TA A-51/PS2, 34398 Montpellier Cedex 5, France
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8
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Arcila Hernández LM, Sanders JG, Miller GA, Ravenscraft A, Frederickson ME. Ant-plant mutualism: a dietary by-product of a tropical ant's macronutrient requirements. Ecology 2017; 98:3141-3151. [DOI: 10.1002/ecy.2036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/08/2017] [Accepted: 09/14/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Lina M. Arcila Hernández
- Department of Ecology & Evolutionary Biology; University of Toronto; 25 Willcocks Street Toronto Ontario M5S 3B2 Canada
| | - Jon G. Sanders
- Department of Organismic & Evolutionary Biology; Harvard University; 26 Oxford Street Cambridge Massachusetts 02138 USA
| | - Gabriel A. Miller
- Department of Organismic & Evolutionary Biology; Harvard University; 26 Oxford Street Cambridge Massachusetts 02138 USA
| | - Alison Ravenscraft
- Department of Organismic & Evolutionary Biology; Harvard University; 26 Oxford Street Cambridge Massachusetts 02138 USA
| | - Megan E. Frederickson
- Department of Ecology & Evolutionary Biology; University of Toronto; 25 Willcocks Street Toronto Ontario M5S 3B2 Canada
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9
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Reduced damage and epiphyll cover of leaves of Korthalsia rattans that host Camponotus ants in the rain forest of Malaysian Borneo. JOURNAL OF TROPICAL ECOLOGY 2016. [DOI: 10.1017/s0266467416000316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract:Many species of palm produce chambers called domatia that are used by ants as nesting spaces. However, the ecological nature of this association is not well understood, and the information on palm–ant interactions is primarily anecdotal. Here, we conducted a field study in the secondary forest of the Danum Valley Conservation Area, Malaysian Borneo, on 41 individuals of the rattan Korthalsia furtadoana. All studied plants showed signs of a past or present partnership with domatia-nesting ants, as indicated by entry holes in domatia. In 14 plants, our physical disturbance of a stem provoked the appearance of patrolling ants of Camponotus sp. We compared the leaf conditions of rattans with and without patrolling ants, testing whether the presence of ants is linked to improved leaf health. The leaflets of plants with patrolling ants were significantly less physically damaged and less covered by epiphylls. On average, 19% of the leaflets of plants with patrolling ants were damaged (52% in plants without patrolling ants), and the epiphyll cover of their leaflets was 0.2 on our scale of 0–4 (1.3 in plants without patrolling ants). Our results suggest that this poorly studied plant–ant association has a mutualistic character. It seems that the ants take advantage of the nesting space created by the plant partner, while the plants gain protection for their photosynthetic apparatus against herbivores and epiphylls.
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10
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Jones EI, Afkhami ME, Akçay E, Bronstein JL, Bshary R, Frederickson ME, Heath KD, Hoeksema JD, Ness JH, Pankey MS, Porter SS, Sachs JL, Scharnagl K, Friesen ML. Cheaters must prosper: reconciling theoretical and empirical perspectives on cheating in mutualism. Ecol Lett 2015; 18:1270-1284. [PMID: 26388306 DOI: 10.1111/ele.12507] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/13/2015] [Accepted: 08/13/2015] [Indexed: 01/21/2023]
Abstract
Cheating is a focal concept in the study of mutualism, with the majority of researchers considering cheating to be both prevalent and highly damaging. However, current definitions of cheating do not reliably capture the evolutionary threat that has been a central motivation for the study of cheating. We describe the development of the cheating concept and distill a relative-fitness-based definition of cheating that encapsulates the evolutionary threat posed by cheating, i.e. that cheaters will spread and erode the benefits of mutualism. We then describe experiments required to conclude that cheating is occurring and to quantify fitness conflict more generally. Next, we discuss how our definition and methods can generate comparability and integration of theory and experiments, which are currently divided by their respective prioritisations of fitness consequences and traits. To evaluate the current empirical evidence for cheating, we review the literature on several of the best-studied mutualisms. We find that although there are numerous observations of low-quality partners, there is currently very little support from fitness data that any of these meet our criteria to be considered cheaters. Finally, we highlight future directions for research on conflict in mutualisms, including novel research avenues opened by a relative-fitness-based definition of cheating.
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Affiliation(s)
- Emily I Jones
- Department of BioSciences, Rice University, Houston, TX, 77005, USA.,Wissenschaftskolleg zu Berlin, Institute for Advanced Study, 14193, Berlin, Germany.,Department of Entomology, Washington State University, Pullman, WA, 99164, USA
| | - Michelle E Afkhami
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada
| | - Erol Akçay
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Judith L Bronstein
- Department of Ecology & Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Redouan Bshary
- Institute of Biology, University of Neuchâtel, CH-2000 Neuchâtel, Switzerland
| | - Megan E Frederickson
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada
| | - Katy D Heath
- Department of Biology, University of Illinois, Urbana, IL, 61801, USA
| | - Jason D Hoeksema
- Department of Biology, University of Mississippi, University, MS, 38677, USA
| | - Joshua H Ness
- Department of Biology, Skidmore College, Saratoga Springs, NY, 12866, USA
| | - M Sabrina Pankey
- Department of Molecular, Cell and Biomedical Sciences, University of New Hampshire, Durham, NH, 08624, USA
| | - Stephanie S Porter
- Department of Biology, University of California, Riverside, CA, 92521, USA
| | - Joel L Sachs
- Department of Biology, University of California, Riverside, CA, 92521, USA
| | - Klara Scharnagl
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Maren L Friesen
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
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11
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12
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Tarnita CE, Palmer TM, Pringle RM. Colonisation and competition dynamics can explain incomplete sterilisation parasitism in ant–plant symbioses. Ecol Lett 2014; 17:1290-8. [DOI: 10.1111/ele.12336] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/07/2014] [Accepted: 07/09/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Corina E. Tarnita
- Department of Ecology & Evolutionary Biology Princeton University Princeton NJ 08544 USA
- Mpala Research Centre Box 555Nanyuki Kenya
| | - Todd M. Palmer
- Mpala Research Centre Box 555Nanyuki Kenya
- Department of Biology University of Florida Gainesville FL 32611 USA
| | - Robert M. Pringle
- Department of Ecology & Evolutionary Biology Princeton University Princeton NJ 08544 USA
- Mpala Research Centre Box 555Nanyuki Kenya
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13
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Porter SS, Simms EL. Selection for cheating across disparate environments in the legume-rhizobium mutualism. Ecol Lett 2014; 17:1121-9. [PMID: 25039752 DOI: 10.1111/ele.12318] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 05/19/2014] [Accepted: 06/03/2014] [Indexed: 01/18/2023]
Abstract
The primary dilemma in evolutionarily stable mutualisms is that natural selection for cheating could overwhelm selection for cooperation. Cheating need not entail parasitism; selection favours cheating as a quantitative trait whenever less-cooperative partners are more fit than more-cooperative partners. Mutualisms might be stabilised by mechanisms that direct benefits to more-cooperative individuals, which counter selection for cheating; however, empirical evidence that natural selection favours cheating in mutualisms is sparse. We measured selection on cheating in single-partner pairings of wild legume and rhizobium lineages, which prevented legume choice. Across contrasting environments, selection consistently favoured cheating by rhizobia, but did not favour legumes that provided less benefit to rhizobium partners. This is the first simultaneous measurement of selection on cheating across both host and symbiont lineages from a natural population. We empirically confirm selection for cheating as a source of antagonistic coevolutionary pressure in mutualism and a biological dilemma for models of cooperation.
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Affiliation(s)
- Stephanie S Porter
- Department of Integrative Biology, University of California, 1001 Valley Life Science Building #3140, Berkeley, California, 94720-3140, USA
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14
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Pringle EG. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism. Proc Biol Sci 2014; 281:20140474. [PMID: 24807259 DOI: 10.1098/rspb.2014.0474] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.
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Affiliation(s)
- Elizabeth G Pringle
- Michigan Society of Fellows, University of Michigan, , Ann Arbor, MI 48109, USA, Department of Ecology and Evolutionary Biology, University of Michigan, , Ann Arbor, MI 48109, USA, School of Natural Resources and Environment, University of Michigan, , Ann Arbor, MI 48109, USA
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Temporary sterilization behavior of mutualistic partner ants in a Southeast Asian myrmecophyte. Ecol Res 2014. [DOI: 10.1007/s11284-014-1161-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mayer VE, Frederickson ME, McKey D, Blatrix R. Current issues in the evolutionary ecology of ant-plant symbioses. THE NEW PHYTOLOGIST 2014; 202:749-764. [PMID: 24444030 DOI: 10.1111/nph.12690] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 12/16/2013] [Indexed: 05/08/2023]
Abstract
Ant-plant symbioses involve plants that provide hollow structures specialized for housing ants and often food to ants. In return, the inhabiting ants protect plants against herbivores and sometimes provide them with nutrients. Here, we review recent advances in ant-plant symbioses, focusing on three areas. First, the nutritional ecology of plant-ants, which is based not only on plant-derived food rewards, but also on inputs from other symbiotic partners, in particular fungi and possibly bacteria. Food and protection are the most important 'currencies' exchanged between partners and they drive the nature and evolution of the relationships. Secondly, studies of conflict and cooperation in ant-plant symbioses have contributed key insights into the evolution and maintenance of mutualism, particularly how partner-mediated feedbacks affect the specificity and stability of mutualisms. There is little evidence that mutualistic ants or plants are under selection to cheat, but the costs and benefits of ant-plant interactions do vary with environmental factors, making them vulnerable to natural or anthropogenic environmental change. Thus, thirdly, ant-plant symbioses should be considered good models for investigating the effects of global change on the outcome of mutualistic interactions.
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Affiliation(s)
- Veronika E Mayer
- Department of Structural and Functional Botany, Faculty Centre of Biodiversity, University of Vienna, Rennweg 14, A-1030, Wien, Austria
| | - Megan E Frederickson
- Department of Ecology & Evolutionary Biology, University of Toronto, 25 Harbord Street, Toronto, M5S 3G5, Canada
| | - Doyle McKey
- Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 CEFE, Université Montpellier 2, 1919 route de Mende, 34293, Montpellier Cedex 5, France
- Institut Universitaire de France, Université Montpellier 2, Montpellier Cedex 5, France
| | - Rumsaïs Blatrix
- Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 CEFE, CNRS, 1919 route de Mende, 34293, Montpellier Cedex 5, France
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Frederickson ME. Rethinking mutualism stability: cheaters and the evolution of sanctions. QUARTERLY REVIEW OF BIOLOGY 2014; 88:269-95. [PMID: 24552098 DOI: 10.1086/673757] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
How cooperation originates and persists in diverse species, from bacteria to multicellular organisms to human societies, is a major question in evolutionary biology. A large literature asks: what prevents selection for cheating within cooperative lineages? In mutualisms, or cooperative interactions between species, feedback between partners often aligns their fitness interests, such that cooperative symbionts receive more benefits from their hosts than uncooperative symbionts. But how do these feedbacks evolve? Cheaters might invade symbiont populations and select for hosts that preferentially reward or associate with cooperators (often termed sanctions or partner choice); hosts might adapt to variation in symbiont quality that does not amount to cheating (e.g., environmental variation); or conditional host responses might exist before cheaters do, making mutualisms stable from the outset. I review evidence from yucca-yucca moth, fig-fig wasp, and legume-rhizobium mutualisms, which are commonly cited as mutualisms stabilized by sanctions. Based on the empirical evidence, it is doubtful that cheaters select for host sanctions in these systems; cheaters are too uncommon. Recognizing that sanctions likely evolved for functions other than retaliation against cheaters offers many insights about mutualism coevolution, and about why mutualism evolves in only some lineages of potential hosts.
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Affiliation(s)
- Megan E Frederickson
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada.
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Cembrowski AR, Tan MG, Thomson JD, Frederickson ME. Ants and Ant Scent Reduce Bumblebee Pollination of Artificial Flowers. Am Nat 2014; 183:133-9. [DOI: 10.1086/674101] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Orona-Tamayo D, Heil M. Stabilizing Mutualisms Threatened by Exploiters: New Insights from Ant-Plant Research. Biotropica 2013. [DOI: 10.1111/btp.12059] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Domancar Orona-Tamayo
- Departamento de Ingeniería Genética; CINVESTAV-Irapuato; Irapuato Guanajuato Mexico
- Instituto de Investigaciones Químico-Biológicas; Universidad Michoacana de San Nicolás de Hidalgo (UMSNH); Edif. B3, Ciudad Universitaria 58060 Morelia Michoacán Mexico
| | - Martin Heil
- Departamento de Ingeniería Genética; CINVESTAV-Irapuato; Irapuato Guanajuato Mexico
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Malé PJG, Ferdy JB, Leroy C, Roux O, Lauth J, Avilez A, Dejean A, Quilichini A, Orivel J. Retaliation in Response to Castration Promotes a Low Level of Virulence in an Ant–Plant Mutualism. Evol Biol 2013. [DOI: 10.1007/s11692-013-9242-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Dejean A, Orivel J, Rossi V, Roux O, Lauth J, Malé PJG, Céréghino R, Leroy C. Predation success by a plant-ant indirectly favours the growth and fitness of its host myrmecophyte. PLoS One 2013; 8:e59405. [PMID: 23516632 PMCID: PMC3597600 DOI: 10.1371/journal.pone.0059405] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 02/16/2013] [Indexed: 11/29/2022] Open
Abstract
Mutualisms, or interactions between species that lead to net fitness benefits for each species involved, are stable and ubiquitous in nature mostly due to “byproduct benefits” stemming from the intrinsic traits of one partner that generate an indirect and positive outcome for the other. Here we verify if myrmecotrophy (where plants obtain nutrients from the refuse of their associated ants) can explain the stability of the tripartite association between the myrmecophyte Hirtella physophora, the ant Allomerus decemarticulatus and an Ascomycota fungus. The plant shelters and provides the ants with extrafloral nectar. The ants protect the plant from herbivores and integrate the fungus into the construction of a trap that they use to capture prey; they also provide the fungus and their host plant with nutrients. During a 9-month field study, we over-provisioned experimental ant colonies with insects, enhancing colony fitness (i.e., more winged females were produced). The rate of partial castration of the host plant, previously demonstrated, was not influenced by the experiment. Experimental plants showed higher δ15N values (confirming myrmecotrophy), plus enhanced vegetative growth (e.g., more leaves produced increased the possibility of lodging ants in leaf pouches) and fitness (i.e., more fruits produced and more flowers that matured into fruit). This study highlights the importance of myrmecotrophy on host plant fitness and the stability of ant-myrmecophyte mutualisms.
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Affiliation(s)
- Alain Dejean
- Université de Toulouse, UPS, Ecolab, Toulouse, France.
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Frederickson ME, Ravenscraft A, Miller GA, Arcila Hernández LM, Booth G, Pierce NE. The direct and ecological costs of an ant-plant symbiosis. Am Nat 2012; 179:768-78. [PMID: 22617264 DOI: 10.1086/665654] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
How strong is selection for cheating in mutualisms? The answer depends on the type and magnitude of the costs of the mutualism. Here we investigated the direct and ecological costs of plant defense by ants in the association between Cordia nodosa, a myrmecophytic plant, and Allomerus octoarticulatus, a phytoecious ant. Cordia nodosa trees produce food and housing to reward ants that protect them against herbivores. For nearly 1 year, we manipulated the presence of A. octoarticulatus ants and most insect herbivores on C. nodosa in a full-factorial experiment. Ants increased plant growth when herbivores were present but decreased plant growth when herbivores were absent, indicating that hosting ants can be costly to plants. However, we did not detect a cost to ant colonies of defending host plants against herbivores. Although this asymmetry in costs suggests that the plants may be under stronger selection than the ants to cheat by withholding investment in their partner, the costs to C. nodosa are probably at least partly ecological, arising because ants tend scale insects on their host plants. We argue that ecological costs should favor resistance or traits other than cheating and thus that neither partner may face much temptation to cheat.
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Affiliation(s)
- Megan E Frederickson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.
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Rudgers JA, Miller TEX, Ziegler SM, Craven KD. There are many ways to be a mutualist: Endophytic fungus reduces plant survival but increases population growth. Ecology 2012; 93:565-74. [DOI: 10.1890/11-0689.1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Does exogenic food benefit both partners in an ant-plant mutualism? The case of Cecropia obtusa and its guest Azteca plant-ants. C R Biol 2012; 335:214-9. [PMID: 22464429 DOI: 10.1016/j.crvi.2012.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/31/2011] [Accepted: 01/11/2012] [Indexed: 11/22/2022]
Abstract
In the mutualisms involving the myrmecophyte Cecropia obtusa and Azteca ovaticeps or A. alfari, both predatory, the ants defend their host trees from enemies and provide them with nutrients (myrmecotrophy). A. ovaticeps provisioned with prey and then (15)N-enriched food produced more individuals than did control colonies (not artificially provisioned). This was not true for A. alfari colonies, possibly due to differences in the degree of maturity of the colonies for the chosen range of host tree sizes (less than 3m in height). Myrmecotrophy was demonstrated for both Azteca species as provisioning the ants with (15)N-enriched food translated into higher δ(15)N values in host plant tissues, indicating that nitrogen passed from the food to the plant. Thus, the predatory activity of their guest ants benefits the Cecropia trees not only because the ants protect them from defoliators since most prey are phytophagous insects but also because the plant absorbs nutrients.
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Range expansion induces variation in a behavioural trait in an ant–plant mutualism. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2012. [DOI: 10.1016/j.actao.2011.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Leroy C, Corbara B, Pélozuelo L, Carrias JF, Dejean A, Céréghino R. Ant species identity mediates reproductive traits and allocation in an ant-garden bromeliad. ANNALS OF BOTANY 2012; 109:145-152. [PMID: 21984729 PMCID: PMC3241577 DOI: 10.1093/aob/mcr253] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 09/05/2011] [Indexed: 05/29/2023]
Abstract
BACKGROUND AND AIMS Determining the sources of variation in floral morphology is crucial to understanding the mechanisms underlying Angiosperm evolution. The selection of floral and reproductive traits is influenced by the plant's abiotic environment, florivores and pollinators. However, evidence that variations in floral traits result from mutualistic interactions with insects other than pollinators is lacking in the published literature and has rarely been investigated. We aimed to determine whether the association with either Camponotus femoratus or Pachycondyla goeldii (both involved in seed dispersal and plant protection) mediates the reproductive traits and allocation of Aechmea mertensii, an obligatory ant-garden tank-bromeliad, differently. METHODS Floral and reproductive traits were compared between the two A. mertensii ant-gardens. The nitrogen flux from the ants to the bromeliads was investigated through experimental enrichments with stable isotopes ((15)N). KEY RESULTS Camponotus femoratus-associated bromeliads produced inflorescences up to four times longer than did P. goeldii-associated bromeliads. Also, the numbers of flowers and fruits were close to four times higher, and the number of seeds and their mass per fruit were close to 1·5 times higher in C. femoratus than in P. goeldii-associated bromeliads. Furthermore, the (15)N-enrichment experiment showed that C. femoratus-associated bromeliads received more nitrogen from ants than did P. goeldii-associated bromeliads, with subsequent positive repercussions on floral development. Greater benefits were conferred to A. mertensii by the association with C. femoratus compared with P. goeldii ants. CONCLUSIONS We show for the first time that mutualistic associations with ants can result in an enhanced reproductive allocation for the bromeliad A. mertensii. Nevertheless, the strength and direction of the selection of floral and fruit traits change based on the ant species and were not related to light exposure. The different activities and ecological preferences of the ants may play a contrasting role in shaping plant evolution and speciation.
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Affiliation(s)
- Céline Leroy
- CNRS, UMR Ecologie des Forêts de Guyane (UMR-CNRS 8172), Campus Agronomique, F-97379 Kourou cedex, France
| | - Bruno Corbara
- Clermont Université, Université Blaise Pascal, BP 10448, F-63000 Clermont-Ferrand, France
- Laboratoire Microorganismes, Génome et Environnement (UMR-CNRS 6023), F-63177 Aubière, France
| | - Laurent Pélozuelo
- Laboratoire Ecologie Fonctionnelle et Environnement (UMR-CNRS 5245), Université de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
- Université de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Jean-François Carrias
- Clermont Université, Université Blaise Pascal, BP 10448, F-63000 Clermont-Ferrand, France
- Laboratoire Microorganismes, Génome et Environnement (UMR-CNRS 6023), F-63177 Aubière, France
| | - Alain Dejean
- CNRS, UMR Ecologie des Forêts de Guyane (UMR-CNRS 8172), Campus Agronomique, F-97379 Kourou cedex, France
- Université de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Régis Céréghino
- Laboratoire Ecologie Fonctionnelle et Environnement (UMR-CNRS 5245), Université de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
- Université de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
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OÑA L, LACHMANN M. Ant aggression and evolutionary stability in plant-ant and plant-pollinator mutualistic interactions. J Evol Biol 2010; 24:617-29. [DOI: 10.1111/j.1420-9101.2010.02200.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Orivel J, Lambs L, Malé PJG, Leroy C, Grangier J, Otto T, Quilichini A, Dejean A. Dynamics of the association between a long-lived understory myrmecophyte and its specific associated ants. Oecologia 2010; 165:369-76. [PMID: 20683730 DOI: 10.1007/s00442-010-1739-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Accepted: 07/17/2010] [Indexed: 10/19/2022]
Abstract
Myrmecophytic symbioses are widespread in tropical ecosystems and their diversity makes them useful tools for understanding the origin and evolution of mutualisms. Obligate ant-plants, or myrmecophytes, provide a nesting place, and, often, food to a limited number of plant-ant species. In exchange, plant-ants protect their host plants from herbivores, competitors and pathogens, and can provide them with nutrients. Although most studies to date have highlighted a similar global pattern of interactions in these systems, little is known about the temporal structuring and dynamics of most of these associations. In this study we focused on the association between the understory myrmecophyte Hirtella physophora (Chrysobalanaceae) and its obligate ant partner Allomerus decemarticulatus (Myrmicinae). An examination of the life histories and growth rates of both partners demonstrated that this plant species has a much longer lifespan (up to about 350 years) than its associated ant colonies (up to about 21 years). The size of the ant colonies and their reproductive success were strongly limited by the available nesting space provided by the host plants. Moreover, the resident ants positively affected the vegetative growth of their host plant, but had a negative effect on its reproduction by reducing the number of flowers and fruits by more than 50%. Altogether our results are important to understanding the evolutionary dynamics of ant-plant symbioses. The highly specialized interaction between long-lived plants and ants with a shorter lifespan produces an asymmetry in the evolutionary rates of the interaction which, in return, can affect the degree to which the interests of the two partners converge.
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Affiliation(s)
- Jérôme Orivel
- CNRS, UMR Ecologie des Forêts de Guyane, Campus Agronomique, Kourou, France.
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Edwards DP, Frederickson ME, Shepard GH, Yu DW. A plant needs ants like a dog needs fleas: Myrmelachista schumanni ants gall many tree species to create housing. Am Nat 2009; 174:734-40. [PMID: 19799500 DOI: 10.1086/606022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Although we now know that domatia are not galls and that most ant-plant interactions are mutualisms and not parasitisms, we revisit Spruce's suggestion that ants can gall in light of our observations of the plant-ant Myrmelachista schumanni, which creates clearings in the Amazonian rain forest called "supay-chakras," or "devil's gardens." We observed swollen scars on the trunks of nonmyrmecophytic canopy trees surrounding supay-chakras, and within these swellings, we found networks of cavities inhabited by M. schumanni. Here, we summarize the evidence supporting the hypothesis that M. schumanni ants make these galls, and we hypothesize that the adaptive benefit of galling is to increase the amount of nesting space available to M. schumanni colonies.
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Affiliation(s)
- David P Edwards
- Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
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31
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Szilágyi A, Scheuring I, Edwards DP, Orivel J, Yu DW. The evolution of intermediate castration virulence and ant coexistence in a spatially structured environment. Ecol Lett 2009; 12:1306-16. [PMID: 19780787 DOI: 10.1111/j.1461-0248.2009.01382.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- András Szilágyi
- Department of Plant Taxonomy and Ecology, Eötvös University, Pázmány Péter sétány 1C, H-1117 Budapest, Hungary
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Debout GDG, Frederickson ME, Aron S, Yu DW. Unexplained split sex ratios in the neotropical plant-ant, Allomerus octoarticulatus var. demerarae (Myrmicinae): a test of hypotheses. Evolution 2009; 64:126-41. [PMID: 19703224 DOI: 10.1111/j.1558-5646.2009.00824.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigated sex allocation in the Neotropical ant Allomerus octoarticulatus var. demerarae. Because Allomerus is a plant symbiont, we could make geographically extensive collections of complete colonies and of foundresses in saplings, allowing us to estimate not only population- and colony-level sex allocation but also colony resource levels and the relatedness of competing ant foundresses. This species exhibits a strongly split sex ratio, with 80% of mature colonies producing >or=90% of one sex or the other. Our genetic analyses (DNA microsatellites) reveal that Allomerus has a breeding system characterized by almost complete monogyny and a low frequency of polyandry. Contrary to theoretical explanations, we find no difference in worker relatedness asymmetries between female- and male-specialist colonies. Furthermore, no clear link was found between colony sex allocation and life history traits such as the number of mates per queen, or colony size, resource level, or fecundity. We also failed to find significant support for male production by workers, infection by Wolbachia, local resource competition, or local mate competition. We are left with the possibility that Allomerus exhibits split sex ratios because of the evolution of alternative biasing strategies in queens or workers, as recently proposed in the literature.
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Affiliation(s)
- Gabriel D G Debout
- Ecology, Conservation, and Environment Center, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Science, Kunming, Yunnan 65022, China
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