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Abstract
Herding behavior is widespread among herbivorous insect larvae across several orders. These larval societies represent one of several different forms of insect sociality that have historically received less attention than the well-known eusocial model but are showing us that social diversity in insects is broader than originally imagined. These alternative forms of sociality often focus attention on the ecology, rather than the genetics, of sociality. Indeed, mutually beneficial cooperation among individuals is increasingly recognized as important relative to relatedness in the evolution of sociality, and I will explore its role in larval insect herds. Larval herds vary in in the complexity of their social behavior but what they have in common includes exhibiting specialized social behaviors that are ineffective in isolated individuals but mutually beneficial in groups. They hence constitute cooperation with direct advantages that doesn’t require kinship between cooperators to be adaptive. Examples include: trail following, head-to-tail processions and other behaviors that keep groups together, huddling tightly to bask, synchronized biting and edge-feeding to overwhelm plant defenses, silk production for shelter building or covering plant trichomes and collective defensive behaviors like head-swaying. Various selective advantages to group living have been suggested and I propose that different benefits are at play in different taxa where herding has evolved independently. Proposed benefits include those relative to selection pressure from abiotic factors (e.g., thermoregulation), to bottom-up pressures from plants or to top-down pressures from natural enemies. The adaptive value of herding cooperation must be understood in the context of the organism’s niche and suite of traits. I propose several such suites in herbivorous larvae that occupy different niches. First, some herds aggregate to thermoregulate collectively, particularly in early spring feeders of the temperate zone. Second, other species aggregate to overwhelm host plant defenses, frequently observed in tropical species. Third, species that feed on toxic plants can aggregate to enhance the warning signal produced by aposematic coloration or stereotyped defensive behaviors. Finally, the combination of traits including gregariousness, conspicuous behavior and warning signals can be favored by a synergy between bottom-up and top-down selective forces. When larvae on toxic plants aggregate to overcome plant defenses, this grouping makes them conspicuous to predators and favors warning signals. I thus conclude that a single explanation is not sufficient for the broad range of herding behaviors that occurs in phylogenetically diverse insect larvae in different environments.
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Lihoreau M, Gómez-Moracho T, Pasquaretta C, Costa JT, Buhl C. Social nutrition: an emerging field in insect science. CURRENT OPINION IN INSECT SCIENCE 2018; 28:73-80. [PMID: 30551770 DOI: 10.1016/j.cois.2018.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/01/2018] [Accepted: 05/08/2018] [Indexed: 06/09/2023]
Abstract
Nutrition is thought to be a major driver of social evolution, yet empirical support for this hypothesis is scarce. Here we illustrate how conceptual advances in nutritional ecology illuminate some of the mechanisms by which nutrition mediates social interactions in insects. We focus on experiments and models of nutritional geometry and argue that they provide a powerful means for comparing nutritional phenomena across species exhibiting various social ecologies. This approach, initially developed to study the nutritional behaviour of individual insects, has been increasingly used to study insect groups and societies, leading to the emerging field of social nutrition. We discuss future directions for exploring how these nutritional mechanisms may influence major social transitions in insects and other animals.
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Affiliation(s)
- Mathieu Lihoreau
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI); CNRS, University Paul Sabatier, Toulouse, France.
| | - Tamara Gómez-Moracho
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI); CNRS, University Paul Sabatier, Toulouse, France
| | - Cristian Pasquaretta
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI); CNRS, University Paul Sabatier, Toulouse, France
| | - James T Costa
- Highlands Biological Station, 265 N. Sixth Street, Highlands, NC 28741, USA; Department of Biology, Western Carolina University, Cullowhee, NC 28723, USA
| | - Camille Buhl
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, Southern Australia 5005, Australia
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Costa JT. The other insect societies: overview and new directions. CURRENT OPINION IN INSECT SCIENCE 2018; 28:40-49. [PMID: 30551766 DOI: 10.1016/j.cois.2018.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 06/09/2023]
Abstract
The diversity of societies and forms of social interaction across the Arthropoda is commensurate with the great taxonomic diversity within this pylum. Social evolution research has, however, largely focused on a small subset of social forms; namely, those deemed to be 'eusocial'-groups exhibiting overlapping generations, cooperative brood care, and reproductive division of labor. Here I provide a brief overview of the 'other', non-eusocial, societies of insects and allies, defining the main social traits of interest and summarizing recent work. Four active and emerging fields of inquiry in the other insect societies are discussed.
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Affiliation(s)
- James T Costa
- Highlands Biological Station, 265 N. Sixth Street, Highlands, NC 28741, USA; Department of Biology, Western Carolina University, Cullowhee, NC 28723, USA.
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Host-plant mediated effects on group cohesion and mobility in a nomadic gregarious caterpillar. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2482-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Sasaki T, Pratt SC. The Psychology of Superorganisms: Collective Decision Making by Insect Societies. ANNUAL REVIEW OF ENTOMOLOGY 2018; 63:259-275. [PMID: 28977775 DOI: 10.1146/annurev-ento-020117-043249] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Under the superorganism concept, insect societies are so tightly integrated that they possess features analogous to those of single organisms, including collective cognition. If so, colony function might fruitfully be studied using methods developed to understand individual animals. Here, we review research that uses psychological approaches to understand decision making by colonies. The application of neural models to collective choice shows fundamental similarities between how brains and colonies balance speed/accuracy trade-offs in decision making. Experimental analyses have explored collective rationality, cognitive capacity, and perceptual discrimination at both individual and colony levels. A major theme is the emergence of improved colony-level function from interactions among relatively less capable individuals. However, colonies also encounter performance costs due to their reliance on positive feedback, which generates consensus but can also amplify errors. Collective learning is a nascent field for the further application of psychological methods to colonies. The research strategy reviewed here shows how the superorganism concept can serve as more than an illustrative analogy.
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Affiliation(s)
- Takao Sasaki
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
| | - Stephen C Pratt
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA;
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Swarm intelligence in fish? The difficulty in demonstrating distributed and self-organised collective intelligence in (some) animal groups. Behav Processes 2017; 141:141-151. [DOI: 10.1016/j.beproc.2016.10.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 10/05/2016] [Accepted: 10/08/2016] [Indexed: 12/25/2022]
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Hansen MJ, Schaerf TM, Simpson SJ, Ward AJW. Group foraging decisions in nutritionally differentiated environments. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12646] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew J. Hansen
- Animal Behaviour Lab School of Biological Sciences The University of Sydney Sydney New South Wales 2006 Australia
| | - Timothy M. Schaerf
- Animal Behaviour Lab School of Biological Sciences The University of Sydney Sydney New South Wales 2006 Australia
- School of Science and Technology University of New England Armidale New South Wales 2351 Australia
| | - Stephen J. Simpson
- Charles Perkins Centre The University of Sydney Sydney New South Wales 2006 Australia
| | - Ashley J. W. Ward
- Animal Behaviour Lab School of Biological Sciences The University of Sydney Sydney New South Wales 2006 Australia
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Senior AM, Lihoreau M, Charleston MA, Buhl J, Raubenheimer D, Simpson SJ. Adaptive collective foraging in groups with conflicting nutritional needs. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150638. [PMID: 27152206 PMCID: PMC4852629 DOI: 10.1098/rsos.150638] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/15/2016] [Indexed: 06/05/2023]
Abstract
Collective foraging, based on positive feedback and quorum responses, is believed to improve the foraging efficiency of animals. Nutritional models suggest that social information transfer increases the ability of foragers with closely aligned nutritional needs to find nutrients and maintain a balanced diet. However, whether or not collective foraging is adaptive in a heterogeneous group composed of individuals with differing nutritional needs is virtually unexplored. Here we develop an evolutionary agent-based model using concepts of nutritional ecology to address this knowledge gap. Our aim was to evaluate how collective foraging, mediated by social retention on foods, can improve nutrient balancing in individuals with different requirements. The model suggests that in groups where inter-individual nutritional needs are unimodally distributed, high levels of collective foraging yield optimal individual fitness by reducing search times that result from moving between nutritionally imbalanced foods. However, where nutritional needs are highly bimodal (e.g. where the requirements of males and females differ) collective foraging is selected against, leading to group fission. In this case, additional mechanisms such as assortative interactions can coevolve to allow collective foraging by subgroups of individuals with aligned requirements. Our findings indicate that collective foraging is an efficient strategy for nutrient regulation in animals inhabiting complex nutritional environments and exhibiting a range of social forms.
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Affiliation(s)
- Alistair M. Senior
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Mathematics and Statistics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Mathieu Lihoreau
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Michael A. Charleston
- School of Physical Sciences, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - Jerome Buhl
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - David Raubenheimer
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
- Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Stephen J. Simpson
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
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Santana AFK, McClure M, Ethier J, Despland E. Exploration costs promote conservative collective foraging in the social caterpillar Malacosoma disstria. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.04.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Lihoreau M, Buhl C, Charleston MA, Sword GA, Raubenheimer D, Simpson SJ. Modelling nutrition across organizational levels: from individuals to superorganisms. JOURNAL OF INSECT PHYSIOLOGY 2014; 69:2-11. [PMID: 24681322 DOI: 10.1016/j.jinsphys.2014.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 03/06/2014] [Accepted: 03/12/2014] [Indexed: 06/03/2023]
Abstract
The Geometric Framework for nutrition has been increasingly used to describe how individual animals regulate their intake of multiple nutrients to maintain target physiological states maximizing growth and reproduction. However, only a few studies have considered the potential influences of the social context in which these nutritional decisions are made. Social insects, for instance, have evolved extreme levels of nutritional interdependence in which food collection, processing, storage and disposal are performed by different individuals with different nutritional needs. These social interactions considerably complicate nutrition and raise the question of how nutrient regulation is achieved at multiple organizational levels, by individuals and groups. Here, we explore the connections between individual- and collective-level nutrition by developing a modelling framework integrating concepts of nutritional geometry into individual-based models. Using this approach, we investigate how simple nutritional interactions between individuals can mediate a range of emergent collective-level phenomena in social arthropods (insects and spiders) and provide examples of novel and empirically testable predictions. We discuss how our approach could be expanded to a wider range of species and social systems.
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Affiliation(s)
- Mathieu Lihoreau
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia; Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur la Cognition Animale, Toulouse 31062, France; Université de Toulouse (UPS), Centre de Recherches sur la Cognition Animale, Toulouse 31062, France.
| | - Camille Buhl
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia
| | - Michael A Charleston
- School of Information Technologies, The University of Sydney, NSW 2006, Australia
| | - Gregory A Sword
- Department of Entomology, Interdisciplinary Faculty of Ecology and Evolutionary Biology, Texas A&M University, TX 77843-2475, USA
| | - David Raubenheimer
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia; Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia
| | - Stephen J Simpson
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia
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McClure M, Morcos L, Despland E. Collective choice of a higher-protein food source by gregarious caterpillars occurs through differences in exploration. Behav Ecol 2012. [DOI: 10.1093/beheco/ars141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Leader-based and self-organized communication: modelling group-mass recruitment in ants. J Theor Biol 2012; 313:79-86. [PMID: 22884918 DOI: 10.1016/j.jtbi.2012.07.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 07/22/2012] [Accepted: 07/24/2012] [Indexed: 11/21/2022]
Abstract
For collective decisions to be made, the information acquired by experienced individuals about resources' location has to be shared with naïve individuals through recruitment. Here, we investigate the properties of collective responses arising from a leader-based recruitment and a self-organized communication by chemical trails. We develop a generalized model based on biological data drawn from Tetramorium caespitum ant species of which collective foraging relies on the coupling of group leading and trail recruitment. We show that for leader-based recruitment, small groups of recruits have to be guided in a very efficient way to allow a collective exploitation of food while large group requires less attention from their leader. In the case of self-organized recruitment through a chemical trail, a critical value of trail amount has to be laid per forager in order to launch collective food exploitation. Thereafter, ants can maintain collective foraging by emitting signal intensity below this threshold. Finally, we demonstrate how the coupling of both recruitment mechanisms may benefit to collectively foraging species. These theoretical results are then compared with experimental data from recruitment by T. caespitum ant colonies performing group-mass recruitment towards a single food source. We evidence the key role of leaders as initiators and catalysts of recruitment before this leader-based process is overtaken by self-organised communication through trails. This model brings new insights as well as a theoretical background to empirical studies about cooperative foraging in group-living species.
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Group leadership depends on energetic state in a nomadic collective foraging caterpillar. Behav Ecol Sociobiol 2011. [DOI: 10.1007/s00265-011-1167-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sempo G, Canonge S, Detrain C, Deneubourg JL. Complex Dynamics Based on a Quorum: Decision-Making Process by Cockroaches in a Patchy Environment. Ethology 2009. [DOI: 10.1111/j.1439-0310.2009.01699.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
The primary reason animals, including insect herbivores, eat is to acquire a mix of nutrients needed to fuel the processes of growth, development, and reproduction. Most insect herbivores strongly regulate their nutrient intake when given the opportunity. When they are restricted to imbalanced diets, they employ regulatory rules that govern the extent to which nutrients occurring in excess or deficit are eaten. Insect herbivores also regularly encounter allelochemicals as they eat, and recent work indicates the effect an allelochemical has on nutrient regulation, and insect herbivore performance, is modified depending on a food's nutrient composition. Comparative studies of nutrient regulation suggest coexisting generalist herbivores occupy unique nutritional feeding niches, and work with pathogens and parasitoids has revealed the manner in which top-down pressures influence patterns of nutrient intake. Insect herbivores regulate their nutrient intake using pre- and postingestive mechanisms, plus learning, and there is evidence that some of these mechanisms are shaped by natural selection.
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Affiliation(s)
- Spencer T Behmer
- Department of Entomology, Texas A&M University, College Station Texas, 77845-2475, USA.
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18
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Colasurdo N, Dussutour A, Despland E. Do food protein and carbohydrate content influence the pattern of feeding and the tendency to explore of forest tent caterpillars? JOURNAL OF INSECT PHYSIOLOGY 2007; 53:1160-8. [PMID: 17689556 DOI: 10.1016/j.jinsphys.2007.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/11/2007] [Accepted: 06/13/2007] [Indexed: 05/16/2023]
Abstract
This study examines whether the ratio of protein to carbohydrate affects the timing of meals and the propensity to explore of forest tent caterpillars (Malacosoma disstria). The behavior of fourth instar caterpillars was observed on three semi-defined artificial diets varying in protein (p)-carbohydrate (c) ratio. These diets were (a) p14:c28, (b) p28:c14, and (c) p35:c7. The probability of initiating feeding at first contact with the food and the duration of the first feeding event did not vary across diets, suggesting not much difference in phagostimulatory power. There was also no difference in the total time spent eating, at rest and in motion between diets. However, the timing and duration of meals varied significantly; more short meals were observed on the carbohydrate-biased diet. The duration of pauses between meals also increased with food protein content. Furthermore, caterpillars on the carbohydrate-biased diet were more likely to leave the trail leading to the known food source and to discover a second food source, suggesting that protein deprivation promotes exploration. These findings shed insight into the physiological responses to protein and carbohydrate ingestion and demonstrate how post-ingestive effects can favor consumption of foods containing protein without invoking an explicit mechanism of independent nutrient regulation, but simply by influencing the pattern of feeding and the propensity to explore.
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Affiliation(s)
- Nadia Colasurdo
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, Que., Canada H4B 1R6
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