1
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Gaytán Á, Drobyshev I, Klisho T, Gotthard K, Tack AJM. Parasitism rate differs between herbivore generations in the univoltine, but not bivoltine, range. PLoS One 2023; 18:e0294275. [PMID: 38011177 PMCID: PMC10681160 DOI: 10.1371/journal.pone.0294275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023] Open
Abstract
With climate change, plant-feeding insects increase their number of annual generations (voltinism). However, to what degree the emergence of a new herbivore generation affects the parasitism rate has not been explored. We performed a field experiment to test whether the parasitism rate differs between the first and the second generations of a specialist leaf miner (Tischeria ekebladella), both in the naturally univoltine and bivoltine parts of the leaf miner's distribution. We found an interactive effect between herbivore generation and geographical range on the parasitism rate. The parasitism rate was higher in the first compared to the second host generation in the part of the range that is naturally univoltine, whereas it did not differ between generations in the bivoltine range. Our experiment highlights that shifts in herbivore voltinism might release top-down control, with potential consequences for natural and applied systems.
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Affiliation(s)
- Álvaro Gaytán
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Spanish National Research Council (IRNAS-CSIC), Seville, Spain
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Bolin Center for Climate Research, Stockholm University, Stockholm, Sweden
| | - Igor Drobyshev
- Southern Swedish Forest Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Tatiana Klisho
- Southern Swedish Forest Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Karl Gotthard
- Bolin Center for Climate Research, Stockholm University, Stockholm, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Ayco J. M. Tack
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Bolin Center for Climate Research, Stockholm University, Stockholm, Sweden
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2
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Klapwijk MJ, Bonsall MB. Associational Effects and Indirect Interactions-The Dynamical Effects of Consumer and Resource Traits on Generalist-Resource Interactions. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.854222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Trophic interaction modifications occur in food webs when the direct or indirect interaction between two species is affected by a third species. These behavioral modification effects are often referred to as associational effects. Changes in focal resource availability and consumption by a generalist herbivore can affect a range of outcomes from resource exclusion to multiple resources coexisting with the focal plant species. Here, we investigate the indirect interaction between a focal and alternative resource mediated by a generalist consumer. Using theoretical approaches we analyse the conceptual link between associational effects (both resistance and susceptibility) and the theory of apparent competition and resource switching. We find that changes in focal resource traits have the potential to affect the long-term outcome of indirect interactions. Inclusion of density-dependence expands generalist life-histories and broadens the range where, through associational effects, the availability of alternative resources positively influence a focal resource. We conclude that different forms of associational effects could, in the long-term, lead to a range of indirect interaction dynamics, including apparent competition and apparent mutualism. Our work aims to connects the theoretical body of work on indirect interactions to the concepts of associational effects. The indirect interactions between multiple resources need more thorough investigation to appreciate the range of associational effects that could result from the dynamical interaction between a generalist consumers and its focal and alternative resources.
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3
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Lorusso NS, Faillace CA. Indirect facilitation between prey promotes asymmetric apparent competition. J Anim Ecol 2022; 91:1869-1879. [PMID: 35765925 PMCID: PMC9544837 DOI: 10.1111/1365-2656.13768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 06/17/2022] [Indexed: 11/30/2022]
Abstract
Apparent competition is one mechanism that can contribute to the complex dynamics observed in natural systems, yet it remains understudied in empirical systems. Understanding the dynamics that shape the outcome of processes like apparent competition is vital for appreciating how they influence natural systems. We empirically evaluated the role of indirect trophic interactions in driving apparent competition in a model laboratory system. Our experimental system was designed to let us evaluate combined direct and indirect interactions among species. Here we describe the results of a factorial experiment using two noncompeting prey (Colpidium kleini, a heterotroph, and Chlamydomonas reinhardtii, an autotroph) consumed by a generalist predator Euplotes eurystomus to explore the dynamics of apparent competition. To gain intuition into the potential mechanism driving the asymmetry in the observed results, we further explored the system using structural equation modelling. Our results show an important role of positive interactions and indirect effects contributing to apparent competition in this system with a marked asymmetrical outcome favouring one prey, Chlamydomonas. The selected structural equation supports a role of indirect facilitation; although Chlamydomonas (a photoautotroph) and Colpidium (a bacterivore) use different resources and therefor do not directly compete, Colpidium reduces bacteria that may compete with Chlamydomonas. In addition, formation of colonies by Chlamydomonas in response to predation by Euplotes provides an antipredator defence not available to Colpidium. Asymmetric apparent competition may be more common in natural systems than the symmetric interaction originally proposed in classic theory, suggesting that exploration of the mechanisms driving the asymmetry of the interaction can be a fruitful area of further research to better our understanding of interspecific interactions and community dynamics.
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Affiliation(s)
- Nicholas S Lorusso
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, Jersey.,Current Institution: Department of Life Sciences, University of North Texas at Dallas, 7500 University Hills Blvd, Dallas, Texas, USA
| | - Cara A Faillace
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, Jersey.,Current Institution: University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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4
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Kotula HJ, Peralta G, Frost CM, Todd JH, Tylianakis JM. Predicting direct and indirect non-target impacts of biocontrol agents using machine-learning approaches. PLoS One 2021; 16:e0252448. [PMID: 34061885 PMCID: PMC8168882 DOI: 10.1371/journal.pone.0252448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 05/14/2021] [Indexed: 11/18/2022] Open
Abstract
Biological pest control (i.e. ‘biocontrol’) agents can have direct and indirect non-target impacts, and predicting these effects (especially indirect impacts) remains a central challenge in biocontrol risk assessment. The analysis of ecological networks offers a promising approach to understanding the community-wide impacts of biocontrol agents (via direct and indirect interactions). Independently, species traits and phylogenies have been shown to successfully predict species interactions and network structure (alleviating the need to collect quantitative interaction data), but whether these approaches can be combined to predict indirect impacts of natural enemies remains untested. Whether predictions of interactions (i.e. direct effects) can be made equally well for generalists vs. specialists, abundant vs. less abundant species, and across different habitat types is also untested for consumer-prey interactions. Here, we used two machine-learning techniques (random forest and k-nearest neighbour; KNN) to test whether we could accurately predict empirically-observed quantitative host-parasitoid networks using trait and phylogenetic information. Then, we tested whether the accuracy of machine-learning-predicted interactions depended on the generality or abundance of the interacting partners, or on the source (habitat type) of the training data. Finally, we used these predicted networks to generate predictions of indirect effects via shared natural enemies (i.e. apparent competition), and tested these predictions against empirically observed indirect effects between hosts. We found that random-forest models predicted host-parasitoid pairwise interactions (which could be used to predict attack of non-target host species) more successfully than KNN. This predictive ability depended on the generality of the interacting partners for KNN models, and depended on species’ abundances for both random-forest and KNN models, but did not depend on the source (habitat type) of data used to train the models. Further, although our machine-learning informed methods could significantly predict indirect effects, the explanatory power of our machine-learning models for indirect interactions was reasonably low. Combining machine-learning and network approaches provides a starting point for reducing risk in biocontrol introductions, and could be applied more generally to predicting species interactions such as impacts of invasive species.
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Affiliation(s)
- Hannah J. Kotula
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- * E-mail:
| | - Guadalupe Peralta
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Carol M. Frost
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
| | - Jacqui H. Todd
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Jason M. Tylianakis
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Bio-Protection Research Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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5
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Allen WJ, Waller LP, Barratt BIP, Dickie IA, Tylianakis JM. Exotic plants accumulate and share herbivores yet dominate communities via rapid growth. Nat Commun 2021; 12:2696. [PMID: 33976206 PMCID: PMC8113582 DOI: 10.1038/s41467-021-23030-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 04/07/2021] [Indexed: 11/08/2022] Open
Abstract
Herbivores may facilitate or impede exotic plant invasion, depending on their direct and indirect interactions with exotic plants relative to co-occurring natives. However, previous studies investigating direct effects have mostly used pairwise native-exotic comparisons with few enemies, reached conflicting conclusions, and largely overlooked indirect interactions such as apparent competition. Here, we ask whether native and exotic plants differ in their interactions with invertebrate herbivores. We manipulate and measure plant-herbivore and plant-soil biota interactions in 160 experimental mesocosm communities to test several invasion hypotheses. We find that compared with natives, exotic plants support higher herbivore diversity and biomass, and experience larger proportional biomass reductions from herbivory, regardless of whether specialist soil biota are present. Yet, exotics consistently dominate community biomass, likely due to their fast growth rates rather than strong potential to exert apparent competition on neighbors. We conclude that polyphagous invertebrate herbivores are unlikely to play significant direct or indirect roles in mediating plant invasions, especially for fast-growing exotic plants.
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Affiliation(s)
- Warwick J Allen
- The Bio-Protection Research Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- The Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.
| | - Lauren P Waller
- The Bio-Protection Research Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- The Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Barbara I P Barratt
- AgResearch, Invermay Research Centre, Mosgiel, New Zealand
- Department of Botany, University of Otago, Dunedin, New Zealand
| | - Ian A Dickie
- The Bio-Protection Research Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Jason M Tylianakis
- The Bio-Protection Research Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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6
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Miller KE, Aguilera G, Bommarco R, Roslin T. Land-use intensity affects the potential for apparent competition within and between habitats. J Anim Ecol 2021; 90:1891-1905. [PMID: 33901299 DOI: 10.1111/1365-2656.13508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/15/2021] [Indexed: 11/27/2022]
Abstract
Arthropod communities dwelling in adjacent habitats are able to impact one another via shared natural enemies. In agricultural landscapes, drastic differences in resource availability between crop and non-crop habitats cause variation in insect herbivore densities over short distances, potentially driving inter-habitat effects. Moreover, the composition of the landscape in which the habitats are embedded likely affects realised attack rates from natural enemies via impacts on local arthropod community structure. Here, we examine indirect effects between herbivore species within and between habitat types by calculating the potential for apparent competition between multiple populations. Firstly, we aim to determine how disparities in resource availability impact the strength of the potential for apparent competition occurring between habitats, secondly to examine the impact of landscape composition upon these effects, and finally to couch these observations in reality by investigating the link between the potential for apparent competition and realised attack rates. We used DNA metabarcoding to characterise host-parasitoid interactions within two habitat types (with divergent nutrient inputs) at 11 locations with variable landscape composition within an agroecosystem context. We then used these interaction networks to estimate the potential for apparent competition between each host pair and to compare expected versus realised attack rates across the system. Shared natural enemies were found to structure host herbivore communities within and across habitat boundaries. The size of this effect was related to the resource availability of habitats, such that the habitat with high nutrient input exerted a stronger effect. The overall potential for apparent competition declined with increasing land-use intensity in the surrounding landscape and exhibited a discernible impact on realised attack rates upon herbivore species. Thus, our results suggest that increasing the proportion of perennial habitat in agroecosystems could increase the prevalence of indirect effects such as apparent competition among insect herbivore communities, potentially leading to enhanced population regulation via increased attack rates from natural enemies like parasitoid wasps.
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Affiliation(s)
- Kirsten E Miller
- Department of Ecology, The Swedish University of Agricultural Sciences, Uppsala, Sweden.,School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Guillermo Aguilera
- Department of Ecology, The Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Riccardo Bommarco
- Department of Ecology, The Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tomas Roslin
- Department of Ecology, The Swedish University of Agricultural Sciences, Uppsala, Sweden.,University of Helsinki, Helsinki, Finland
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7
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Monticelli LS, Bishop J, Desneux N, Gurr GM, Jaworski CC, McLean AH, Thomine E, Vanbergen AJ. Multiple global change impacts on parasitism and biocontrol services in future agricultural landscapes. ADV ECOL RES 2021. [DOI: 10.1016/bs.aecr.2021.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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8
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Downey H, Lewis OT, Bonsall MB, Ward A, Gripenberg S. Assessing the potential for indirect interactions between tropical tree species via shared insect seed predators. Biotropica 2020. [DOI: 10.1111/btp.12759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Harriet Downey
- Department of Zoology University of Cambridge Cambridge UK
- Department of Zoology University of Oxford Oxford UK
| | - Owen T. Lewis
- Department of Zoology University of Oxford Oxford UK
| | | | - Alan Ward
- Department of Zoology University of Oxford Oxford UK
| | - Sofia Gripenberg
- Department of Zoology University of Oxford Oxford UK
- School of Biological Sciences University of Reading Reading UK
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9
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Terry JCD, Bonsall MB, Morris RJ. Identifying important interaction modifications in ecological systems. OIKOS 2019. [DOI: 10.1111/oik.06353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Michael B. Bonsall
- Dept of Zoology, Univ. of Oxford Oxford OX1 3PS UK
- St. Peter's College Oxford UK
| | - Rebecca J. Morris
- Dept of Zoology, Univ. of Oxford Oxford OX1 3PS UK
- School of Biological Sciences, Univ. Of Southampton Southampton UK
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10
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Simmons BI, Cirtwill AR, Baker NJ, Wauchope HS, Dicks LV, Stouffer DB, Sutherland WJ. Motifs in bipartite ecological networks: uncovering indirect interactions. OIKOS 2018. [DOI: 10.1111/oik.05670] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Benno I. Simmons
- Dept of Zoology, Univ. of Cambridge, The David Attenborough Building, Pembroke Street; Cambridge CB2 3QZ UK
| | - Alyssa R. Cirtwill
- Dept of Physics, Chemistry and Biology (IFM), Linköping Univ; Linköping Sweden
| | - Nick J. Baker
- Centre for Integrative Ecology, School of Biological Sciences, Univ. of Canterbury; Christchurch New Zealand
| | - Hannah S. Wauchope
- Dept of Zoology, Univ. of Cambridge, The David Attenborough Building, Pembroke Street; Cambridge CB2 3QZ UK
| | - Lynn V. Dicks
- School of Biological Sciences, Univ. of East Anglia; UK
| | - Daniel B. Stouffer
- Centre for Integrative Ecology, School of Biological Sciences, Univ. of Canterbury; Christchurch New Zealand
| | - William J. Sutherland
- Dept of Zoology, Univ. of Cambridge, The David Attenborough Building, Pembroke Street; Cambridge CB2 3QZ UK
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11
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Zwolak R, Witczuk J, Bogdziewicz M, Rychlik L, Pagacz S. Simultaneous population fluctuations of rodents in montane forests and alpine meadows suggest indirect effects of tree masting. J Mammal 2018. [DOI: 10.1093/jmammal/gyy034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Rafał Zwolak
- Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University, Umultowska, Poznań, Poland
| | - Julia Witczuk
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza, Warszawa, Poland
| | - Michał Bogdziewicz
- Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University, Umultowska, Poznań, Poland
- CREAF, Campus de Bellaterra (UAB) Edifici C, Cerdanyola del Valles, Catalonia, Spain
| | - Leszek Rychlik
- Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University, Umultowska, Poznań, Poland
| | - Stanisław Pagacz
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza, Warszawa, Poland
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12
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Godoy O, Bartomeus I, Rohr RP, Saavedra S. Towards the Integration of Niche and Network Theories. Trends Ecol Evol 2018; 33:287-300. [DOI: 10.1016/j.tree.2018.01.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 01/13/2018] [Accepted: 01/15/2018] [Indexed: 12/31/2022]
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13
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Blanchet FG, Roslin T, Kimura MT, Huotari T, Kaartinen R, Gripenberg S, Tack AJM. Related herbivore species show similar temporal dynamics. J Anim Ecol 2018; 87:801-812. [DOI: 10.1111/1365-2656.12807] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/12/2017] [Indexed: 11/29/2022]
Affiliation(s)
- F. Guillaume Blanchet
- Département de biologie; Faculté des sciences; Université de Sherbrooke; Sherbrooke QC Canada
| | - Tomas Roslin
- Department of Ecology; Swedish Univ. of Agricultural Sciences; Uppsala Sweden
- Department of Agricultural Sciences; University of Helsinki; Helsinki Finland
| | | | - Tea Huotari
- Department of Agricultural Sciences; University of Helsinki; Helsinki Finland
| | - Riikka Kaartinen
- Ashworth Laboratories; School of Biological Sciences; University of Edinburgh; Edinburgh UK
| | | | - Ayco J. M. Tack
- Department of Ecology; Environment and Plant Sciences; Stockholm University; Stockholm Sweden
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14
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Abstract
Most species have one or more natural enemies, e.g., predators, parasites, pathogens, and herbivores, among others. These species in turn typically attack multiple victim species. This leads to the possibility of indirect interactions among those victims, both positive and negative. The term apparent competition commonly denotes negative indirect interactions between victim species that arise because they share a natural enemy. This indirect interaction, which in principle can be reflected in many facets of the distribution and abundance of individual species and more broadly govern the structure of ecological communities in time and space, pervades many natural ecosystems. It also is a central theme in many applied ecological problems, including the control of agricultural pests, harvesting, the conservation of endangered species, and the dynamics of emerging diseases. At one end of the scale of life, apparent competition characterizes intriguing aspects of dynamics within individual organisms—for example, the immune system is akin in many ways to a predator that can induce negative indirect interactions among different pathogens. At intermediate scales of biological organization, the existence and strength of apparent competition depend upon many contingent details of individual behavior and life history, as well as the community and spatial context within which indirect interactions play out. At the broadest scale of macroecology and macroevolution, apparent competition may play a major, if poorly understood, role in the evolution of species’ geographical ranges and adaptive radiations.
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Affiliation(s)
- Robert D. Holt
- Department of Biology, University of Florida, Gainesville, Florida 32611 USA
| | - Michael B. Bonsall
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
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15
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Terry JCD, Morris RJ, Bonsall MB. Trophic interaction modifications: an empirical and theoretical framework. Ecol Lett 2017; 20:1219-1230. [PMID: 28921859 PMCID: PMC6849598 DOI: 10.1111/ele.12824] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/01/2017] [Accepted: 07/17/2017] [Indexed: 12/01/2022]
Abstract
Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity.
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Affiliation(s)
| | - Rebecca J. Morris
- Department of ZoologyUniversity of OxfordOxfordOX1 3PSUK
- Biological Sciences, Faculty of Natural and Environmental SciencesUniversity of SouthamptonLife Sciences Building 85Highfield CampusSouthamptonSO17 1BJUK
| | - Michael B. Bonsall
- Department of ZoologyUniversity of OxfordOxfordOX1 3PSUK
- St. Peter's CollegeNew Inn Hall StreetOxfordOX1 2DLUK
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16
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Ovaskainen O, Tikhonov G, Norberg A, Guillaume Blanchet F, Duan L, Dunson D, Roslin T, Abrego N. How to make more out of community data? A conceptual framework and its implementation as models and software. Ecol Lett 2017; 20:561-576. [PMID: 28317296 DOI: 10.1111/ele.12757] [Citation(s) in RCA: 322] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/31/2017] [Accepted: 02/09/2017] [Indexed: 12/23/2022]
Abstract
Community ecology aims to understand what factors determine the assembly and dynamics of species assemblages at different spatiotemporal scales. To facilitate the integration between conceptual and statistical approaches in community ecology, we propose Hierarchical Modelling of Species Communities (HMSC) as a general, flexible framework for modern analysis of community data. While non-manipulative data allow for only correlative and not causal inference, this framework facilitates the formulation of data-driven hypotheses regarding the processes that structure communities. We model environmental filtering by variation and covariation in the responses of individual species to the characteristics of their environment, with potential contingencies on species traits and phylogenetic relationships. We capture biotic assembly rules by species-to-species association matrices, which may be estimated at multiple spatial or temporal scales. We operationalise the HMSC framework as a hierarchical Bayesian joint species distribution model, and implement it as R- and Matlab-packages which enable computationally efficient analyses of large data sets. Armed with this tool, community ecologists can make sense of many types of data, including spatially explicit data and time-series data. We illustrate the use of this framework through a series of diverse ecological examples.
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Affiliation(s)
- Otso Ovaskainen
- Department of Biosciences, University of Helsinki, P.O. Box 65, Helsinki, FI-00014, Finland.,Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Gleb Tikhonov
- Department of Biosciences, University of Helsinki, P.O. Box 65, Helsinki, FI-00014, Finland
| | - Anna Norberg
- Department of Biosciences, University of Helsinki, P.O. Box 65, Helsinki, FI-00014, Finland
| | - F Guillaume Blanchet
- Department of Mathematics and Statistics, McMaster University, 1280 Main Street West Hamilton, Ontario, L8S 4K1, Canada.,Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 Boulevard Université Sherbrooke, Québec, J1K 2R1, Canada
| | - Leo Duan
- Department of Statistical Science, Duke University, P.O. Box 90251, Durham, USA
| | - David Dunson
- Department of Statistical Science, Duke University, P.O. Box 90251, Durham, USA
| | - Tomas Roslin
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, Uppsala, 75651, Sweden
| | - Nerea Abrego
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, N-7491, Trondheim, Norway.,Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, Helsinki, FI-00014, Finland
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17
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López-Núñez FA, Heleno RH, Ribeiro S, Marchante H, Marchante E. Four-trophic level food webs reveal the cascading impacts of an invasive plant targeted for biocontrol. Ecology 2017; 98:782-793. [DOI: 10.1002/ecy.1701] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/21/2016] [Accepted: 11/29/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Francisco A. López-Núñez
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra Portugal
| | - Ruben H. Heleno
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra Portugal
| | - Sérgio Ribeiro
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra Portugal
| | - Hélia Marchante
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra Portugal
- Department of Environment; Coimbra Polytechnic Institute, Higher School of Agriculture; Bencanta 3045-601 Coimbra Portugal
| | - Elizabete Marchante
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra Portugal
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18
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Lee DE, Kissui BM, Kiwango YA, Bond ML. Migratory herds of wildebeests and zebras indirectly affect calf survival of giraffes. Ecol Evol 2016; 6:8402-8411. [PMID: 28031792 PMCID: PMC5167056 DOI: 10.1002/ece3.2561] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/14/2016] [Accepted: 09/22/2016] [Indexed: 11/24/2022] Open
Abstract
In long‐distance migratory systems, local fluctuations in the predator–prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. Such systems offer an opportunity to empirically investigate cyclic population density effects on short‐term food web interactions by taking advantage of the large seasonal shifts in migratory prey biomass. We utilized a large‐mammal predator–prey savanna food web to evaluate support for hypotheses relating to the indirect effects of “apparent competition” and “apparent mutualism” from migratory ungulate herds on survival of resident megaherbivore calves, mediated by their shared predator. African lions (Panthera leo) are generalist predators whose primary, preferred prey are wildebeests (Connochaetes taurinus) and zebras (Equus quagga), while lion predation on secondary prey such as giraffes (Giraffa camelopardalis) may change according to the relative abundance of the primary prey species. We used demographic data from five subpopulations of giraffes in the Tarangire Ecosystem of Tanzania, East Africa, to test hypotheses relating to direct predation and indirect effects of large migratory herds on calf survival of a resident megaherbivore. We examined neonatal survival via apparent reproduction of 860 adult females, and calf survival of 449 giraffe calves, during three precipitation seasons over 3 years, seeking evidence of some effect on neonate and calf survival as a consequence of the movements of large herds of migratory ungulates. We found that local lion predation pressure (lion density divided by primary prey density) was significantly negatively correlated with giraffe neonatal and calf survival probabilities. This supports the apparent mutualism hypothesis that the presence of migratory ungulates reduces lion predation on giraffe calves. Natural predation had a significant effect on giraffe calf and neonate survival, and could significantly affect giraffe population dynamics. If wildebeest and zebra populations in this ecosystem continue to decline as a result of increasingly disrupted migrations and poaching, then giraffe calves will face increased predation pressure as the predator–prey ratio increases. Our results suggest that the widespread population declines observed in many migratory systems are likely to trigger demographic impacts in other species due to indirect effects like those shown here.
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Frost CM, Peralta G, Rand TA, Didham RK, Varsani A, Tylianakis JM. Apparent competition drives community-wide parasitism rates and changes in host abundance across ecosystem boundaries. Nat Commun 2016; 7:12644. [PMID: 27577948 PMCID: PMC5013663 DOI: 10.1038/ncomms12644] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 07/19/2016] [Indexed: 11/21/2022] Open
Abstract
Species have strong indirect effects on others, and predicting these effects is a central challenge in ecology. Prey species sharing an enemy (predator or parasitoid) can be linked by apparent competition, but it is unknown whether this process is strong enough to be a community-wide structuring mechanism that could be used to predict future states of diverse food webs. Whether species abundances are spatially coupled by enemy movement across different habitats is also untested. Here, using a field experiment, we show that predicted apparent competitive effects between species, mediated via shared parasitoids, can significantly explain future parasitism rates and herbivore abundances. These predictions are successful even across edges between natural and managed forests, following experimental reduction of herbivore densities by aerial spraying of insecticide over 20 hectares. This result shows that trophic indirect effects propagate across networks and habitats in important, predictable ways, with implications for landscape planning, invasion biology and biological control. Species sharing a common enemy such as a parasitoid or predator can indirectly affect one another. Here, Frost et al. use quantitative food-web data from communities of caterpillar hosts to show experimentally that apparent competition is important in predicting food-web structure across habitats.
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Affiliation(s)
- Carol M Frost
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Guadalupe Peralta
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Tatyana A Rand
- USDA-ARS Northern Plains Agricultural Research Laboratory, Sidney, Montana 59270, USA
| | - Raphael K Didham
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009, Australia.,CSIRO Land &Water, Centre for Environment and Life Sciences, Underwood Ave, Floreat Western Australia 6014, Australia
| | - Arvind Varsani
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.,Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.,Structural Biology Research Unit, Department of Clinical Laboratory Sciences, University of Cape Town, Observatory, Cape Town 7700, South Africa.,Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, Florida 32611, USA
| | - Jason M Tylianakis
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.,Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, UK
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Roslin T, Majaneva S. The use of DNA barcodes in food web construction-terrestrial and aquatic ecologists unite! Genome 2016; 59:603-28. [PMID: 27484156 DOI: 10.1139/gen-2015-0229] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
By depicting who eats whom, food webs offer descriptions of how groupings in nature (typically species or populations) are linked to each other. For asking questions on how food webs are built and work, we need descriptions of food webs at different levels of resolution. DNA techniques provide opportunities for highly resolved webs. In this paper, we offer an exposé of how DNA-based techniques, and DNA barcodes in particular, have recently been used to construct food web structure in both terrestrial and aquatic systems. We highlight how such techniques can be applied to simultaneously improve the taxonomic resolution of the nodes of the web (i.e., the species), and the links between them (i.e., who eats whom). We end by proposing how DNA barcodes and DNA information may allow new approaches to the construction of larger interaction webs, and overcome some hurdles to achieving adequate sample size. Most importantly, we propose that the joint adoption and development of these techniques may serve to unite approaches to food web studies in aquatic and terrestrial systems-revealing the extent to which food webs in these environments are structured similarly to or differently from each other, and how they are linked by dispersal.
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Affiliation(s)
- Tomas Roslin
- a Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden.,b Spatial Foodweb Ecology Group, Department of Agricultural Sciences, PO Box 27, (Latokartanonkaari 5), FI-00014 University of Helsinki, Finland
| | - Sanna Majaneva
- c Centre for Ecology and Evolution in Microbial model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, 39182 Kalmar, Sweden
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Kaser JM, Ode PJ. Hidden risks and benefits of natural enemy-mediated indirect effects. CURRENT OPINION IN INSECT SCIENCE 2016; 14:105-111. [PMID: 27436655 DOI: 10.1016/j.cois.2016.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/03/2016] [Indexed: 06/06/2023]
Abstract
Polyphagous natural enemies can mediate a variety of indirect interactions between resource populations. Such indirect interactions are often reciprocally negative (i.e. apparent competition), but the sign of effects between resource populations can be any combination of positive (+), negative (-), or neutral (0). In this article we focus on parasitoids to illustrate the importance of natural enemy-mediated indirect interactions in predicting risk and efficacy in biological control. We review recent findings to illustrate how an improved understanding of parasitoid behavioral ecology may increase model accuracy.
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Affiliation(s)
- Joe M Kaser
- Department of Entomology, University of Minnesota, Saint Paul, MN 55108, USA.
| | - Paul J Ode
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
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Zheng C, Ovaskainen O, Roslin T, Tack AJM. Beyond metacommunity paradigms: habitat configuration, life history, and movement shape an herbivore community on oak. Ecology 2016; 96:3175-85. [PMID: 26909424 DOI: 10.1890/15-0180.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Many empirical studies of metacommunities have focused on the classification of observational patterns into four contrasting paradigms characterized by different levels of movement and habitat heterogeneity. However, deeper insight into the underlying local and regional processes may be derived from a combination of long-term observational data and experimental studies. With the aim of exploring forces structuring the insect metacommunity on oak, we fit a hierarchical Bayesian state-space model to data from observations and experiments. The fitted model reveals large variation in species-specific dispersal abilities and basic reproduction numbers, R0. The residuals from the model show only weak correlations among species, suggesting a lack of strong interspecific interactions. Simulations with model-derived parameter estimates indicate that habitat configuration and species attributes both contribute substantially to structuring insect communities. Overall, our findings demonstrate that community-level variation in movement and life history are key drivers of metacommunity dynamics.
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24
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Hrček J, Godfray HCJ. What do molecular methods bring to host–parasitoid food webs? Trends Parasitol 2015; 31:30-5. [DOI: 10.1016/j.pt.2014.10.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/22/2014] [Accepted: 10/29/2014] [Indexed: 01/20/2023]
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Chailleux A, Mohl EK, Teixeira Alves M, Messelink GJ, Desneux N. Natural enemy-mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems. PEST MANAGEMENT SCIENCE 2014; 70:1769-1779. [PMID: 25256611 DOI: 10.1002/ps.3916] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/20/2014] [Accepted: 09/20/2014] [Indexed: 06/03/2023]
Abstract
Understanding how arthropod pests and their natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of natural enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for enemy-mediated indirect interactions to be applied to biological control.
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Affiliation(s)
- Anaïs Chailleux
- French National Institute for Agricultural Reseach (INRA), UMR1355-ISA, Sophia-Antipolis, France; InVivo AgroSolutions, Paris, France; CIRAD, UPR HortSys, Montpellier, France
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26
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Poisot T, Stouffer DB, Gravel D. Beyond species: why ecological interaction networks vary through space and time. OIKOS 2014. [DOI: 10.1111/oik.01719] [Citation(s) in RCA: 283] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Timothée Poisot
- School of Biological Sciences, Univ. of Canterbury; Christchurch New Zealand
- Québec Centre for Biodiversity Sciences; Montréal, QC Canada
| | - Daniel B. Stouffer
- School of Biological Sciences, Univ. of Canterbury; Christchurch New Zealand
| | - Dominique Gravel
- Québec Centre for Biodiversity Sciences; Montréal, QC Canada
- Dept of Biology; Univ. du Québec à Rimouski; Rimouski, QC G5L 3A1 Canada
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Carvalheiro LG, Biesmeijer JC, Benadi G, Fründ J, Stang M, Bartomeus I, Kaiser-Bunbury CN, Baude M, Gomes SIF, Merckx V, Baldock KCR, Bennett ATD, Boada R, Bommarco R, Cartar R, Chacoff N, Dänhardt J, Dicks LV, Dormann CF, Ekroos J, Henson KS, Holzschuh A, Junker RR, Lopezaraiza-Mikel M, Memmott J, Montero-Castaño A, Nelson IL, Petanidou T, Power EF, Rundlöf M, Smith HG, Stout JC, Temitope K, Tscharntke T, Tscheulin T, Vilà M, Kunin WE. The potential for indirect effects between co-flowering plants via shared pollinators depends on resource abundance, accessibility and relatedness. Ecol Lett 2014; 17:1389-99. [DOI: 10.1111/ele.12342] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/26/2014] [Accepted: 07/20/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Luísa Gigante Carvalheiro
- School of Biology; University of Leeds; Leeds LS2 9JT UK
- Naturalis Biodiversity Center; RA Leiden 2300 The Netherlands
| | - Jacobus Christiaan Biesmeijer
- Naturalis Biodiversity Center; RA Leiden 2300 The Netherlands
- Institute for Biodiversity and Ecosystems Dynamics (IBED); University of Amsterdam; Amsterdam The Netherlands
| | - Gita Benadi
- Department of Biometry and Environmental Systems Analysis; University of Freiburg; Tennenbacherstr. 4 Freiburg i. Br 79106 Germany
| | - Jochen Fründ
- Department of Integrative Biology; University of Guelph; Ontario N1G 2W1 Canada
| | - Martina Stang
- Institute of Biology; University of Leiden; RA Leiden 2300 The Netherlands
| | | | | | - Mathilde Baude
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
- Collégium Sciences et Techniques (LBLGC-1207); Université d'Orléans; Orléans F-45067 France
| | | | - Vincent Merckx
- Naturalis Biodiversity Center; RA Leiden 2300 The Netherlands
| | | | - Andrew T. D. Bennett
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
- Centre for Integrative Ecology; Deakin University; Victoria 3217 Australia
| | - Ruth Boada
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
| | - Riccardo Bommarco
- Department of Ecology; Swedish University of Agricultural Sciences; Uppsala SE-75007 Sweden
| | - Ralph Cartar
- Department of Biological Sciences; University of Calgary; Calgary AB T2N 1N4 Canada
| | - Natacha Chacoff
- Fac. de Cs Nat. e IML; Instituto de Ecología Regional; Universidad Nacional de Tucumán; Tucumán Argentina
| | - Juliana Dänhardt
- Centre for Environmental and Climate Research & Department of Biology; Lund University; Lund S-223 62 Sweden
| | - Lynn V. Dicks
- Department of Zoology; University of Cambridge; Cambridge UK
| | - Carsten F. Dormann
- Department of Biometry and Environmental Systems Analysis; University of Freiburg; Tennenbacherstr. 4 Freiburg i. Br 79106 Germany
| | - Johan Ekroos
- Centre for Environmental and Climate Research & Department of Biology; Lund University; Lund S-223 62 Sweden
| | - Kate S.E. Henson
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
| | - Andrea Holzschuh
- Animal Ecology and Tropical Biology; University of Würzburg; Würzburg 97074 Germany
| | - Robert R. Junker
- Department of Organismic Biology; University Salzburg; Salzburg 5020 Austria
| | - Martha Lopezaraiza-Mikel
- Unidad Académica en Desarrollo Sustentable; Universidad Autónoma de Guerrero; Guerrero 40900 México
| | - Jane Memmott
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
| | | | - Isabel L. Nelson
- School of Biological Sciences; University of Bristol; Bristol BS8 1UG UK
| | - Theodora Petanidou
- Department of Geography; Laboratory of Biogeography and Ecology; University of the Aegean; Mytilene Lesvos 81100 Greece
| | - Eileen F. Power
- School of Natural Sciences and Trinity Centre for Biodiversity Research; Trinity College Dublin; Dublin 2 Ireland
| | - Maj Rundlöf
- Centre for Environmental and Climate Research & Department of Biology; Lund University; Lund S-223 62 Sweden
| | - Henrik G. Smith
- Centre for Environmental and Climate Research & Department of Biology; Lund University; Lund S-223 62 Sweden
| | - Jane C. Stout
- School of Natural Sciences and Trinity Centre for Biodiversity Research; Trinity College Dublin; Dublin 2 Ireland
| | - Kehinde Temitope
- Department of Conservation Ecology and Entomology; Stellenbosch University; Stellenbosch South Africa
- Department of Zoology; Obafemi Awolowo University; Ile-Ife Nigeria
| | | | - Thomas Tscheulin
- Department of Geography; Laboratory of Biogeography and Ecology; University of the Aegean; Mytilene Lesvos 81100 Greece
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Derocles SAP, Le Ralec A, Besson MM, Maret M, Walton A, Evans DM, Plantegenest M. Molecular analysis reveals high compartmentalization in aphid-primary parasitoid networks and low parasitoid sharing between crop and noncrop habitats. Mol Ecol 2014; 23:3900-11. [PMID: 24612360 DOI: 10.1111/mec.12701] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/19/2014] [Accepted: 02/19/2014] [Indexed: 12/18/2022]
Abstract
The ecosystem service of insect pest regulation by natural enemies, such as primary parasitoids, may be enhanced by the presence of uncultivated, semi-natural habitats within agro-ecosystems, although quantifying such host-parasitoid interactions is difficult. Here, we use rRNA 16S gene sequencing to assess both the level of parasitism by Aphidiinae primary parasitoids and parasitoid identity on a large sample of aphids collected in cultivated and uncultivated agricultural habitats in Western France. We used these data to construct ecological networks to assess the level of compartmentalization between aphid and parasitoid food webs of cultivated and uncultivated habitats. We evaluated the extent to which uncultivated margins provided a resource for parasitoids shared between pest and nonpest aphids. We compared the observed quantitative ecological network described by our molecular approach to an empirical qualitative network based on aphid-parasitoid interactions from traditional rearing data found in the literature. We found that the molecular network was highly compartmentalized and that parasitoid sharing is relatively rare between aphids, especially between crop and noncrop compartments. Moreover, the few cases of putative shared generalist parasitoids were questionable and could be due to the lack of discrimination of cryptic species or from intraspecific host specialization. Our results suggest that apparent competition mediated by Aphidiinae parasitoids is probably rare in agricultural areas and that the contribution of field margins as a source of these biocontrol agents is much more limited than expected. Further large-scale (spatial and temporal) studies on other crops and noncrop habitats are needed to confirm this.
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Affiliation(s)
- Stephane A P Derocles
- Agrocampus Ouest, UMR1349 IGEPP, 65 rue de Saint-Brieuc, CS 84215, 35 042, Rennes Cedex, France; School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, HU6 7RX, UK
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Preference and prey switching in a generalist predator attacking local and invasive alien pests. PLoS One 2013; 8:e82231. [PMID: 24312646 PMCID: PMC3846826 DOI: 10.1371/journal.pone.0082231] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 10/22/2013] [Indexed: 11/21/2022] Open
Abstract
Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae) when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the invasive alien pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage) may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology), the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato.
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Roslin T, Wirta H, Hopkins T, Hardwick B, Várkonyi G. Indirect interactions in the High Arctic. PLoS One 2013; 8:e67367. [PMID: 23826279 PMCID: PMC3691180 DOI: 10.1371/journal.pone.0067367] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 05/16/2013] [Indexed: 11/23/2022] Open
Abstract
Indirect interactions as mediated by higher and lower trophic levels have been advanced as key forces structuring herbivorous arthropod communities around the globe. Here, we present a first quantification of the interaction structure of a herbivore-centered food web from the High Arctic. Targeting the Lepidoptera of Northeast Greenland, we introduce generalized overlap indices as a novel tool for comparing different types of indirect interactions. First, we quantify the scope for top-down-up interactions as the probability that a herbivore attacking plant species i itself fed as a larva on species j. Second, we gauge this herbivore overlap against the potential for bottom-up-down interactions, quantified as the probability that a parasitoid attacking herbivore species i itself developed as a larva on species j. Third, we assess the impact of interactions with other food web modules, by extending the core web around the key herbivore Sympistis nigrita to other predator guilds (birds and spiders). We find the host specificity of both herbivores and parasitoids to be variable, with broad generalists occurring in both trophic layers. Indirect links through shared resources and through shared natural enemies both emerge as forces with a potential for shaping the herbivore community. The structure of the host-parasitoid submodule of the food web suggests scope for classic apparent competition. Yet, based on predation experiments, we estimate that birds kill as many (8%) larvae of S. nigrita as do parasitoids (8%), and that spiders kill many more (38%). Interactions between these predator guilds may result in further complexities. Our results caution against broad generalizations from studies of limited food web modules, and show the potential for interactions within and between guilds of extended webs. They also add a data point from the northernmost insect communities on Earth, and describe the baseline structure of a food web facing imminent climate change.
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Affiliation(s)
- Tomas Roslin
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
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Bompard A, Jaworski CC, Bearez P, Desneux N. Sharing a predator: can an invasive alien pest affect the predation on a local pest? POPUL ECOL 2013. [DOI: 10.1007/s10144-013-0371-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Henri DC, Seager D, Weller T, van Veen FJF. Potential for climate effects on the size-structure of host-parasitoid indirect interaction networks. Philos Trans R Soc Lond B Biol Sci 2013; 367:3018-24. [PMID: 23007090 DOI: 10.1098/rstb.2012.0236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Communities of insect herbivores are thought to be structured mainly by indirect processes mediated by shared natural enemies, such as apparent competition. In host-parasitoid interaction networks, overlap in natural enemy communities between any pair of host species depends on the realized niches of parasitoids, which ultimately depend on the foraging decisions of individuals. Optimal foraging theory predicts that egg-limited parasitoid females should reject small hosts in favour of future opportunities to oviposit in larger hosts, while time-limited parasitoids are expected to optimize oviposition rate regardless of host size. The degree to which parasitoids are time- or egg-limited depends in part on weather conditions, as this determines the proportion of an individual's lifespan that is available to foraging. Using a 10-year time series of monthly quantitative host-parasitoid webs, we present evidence for host-size-based electivity and sex allocation in the common secondary parasitoid Asaphes vulgaris. We argue that this electivity leads to body-size-dependent asymmetry in apparent competition among hosts and we discuss how changing weather patterns, as a result of climate change, may impact foraging behaviour and thereby the size-structure and dynamics of host-parasitoid indirect interaction networks.
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Affiliation(s)
- Dominic C Henri
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, Cornwall TR10 9EZ, UK
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Blitzer EJ, Welter SC. Emergence asynchrony between herbivores leads to apparent competition in the field. Ecology 2011; 92:2020-6. [DOI: 10.1890/11-0117.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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