Symposia
1. Mechanisms of individual life history evolution in the social context
Olav Rueppell, University of Alberta
Judith Korb, Universität Freiburg
Juergen Heinze, Universität Regensburg
Life history theory is one of the great unifying principles for conceptualizing biological diversity. Social evolution fundamentally changes selection on individual life history optimization. Thus, studying life history is fundamental for understanding the biology of social insects, and the exceptional life history of social insects also provides unique opportunities for general insights into life history evolution. Specifically driven by advances in functional genomics, proteomics, and metabolomics, this symposium will synthesize recent progress in our understanding of the mechanisms of social life histories, including reproduction, behavioral ontogeny, and aging. We will further attempt to integrate such mechanistic findings with current studies that quantify life history at unprecedented scales and precision through automated lifetime monitoring of individuals and advanced analyses. We will pursue the overarching question whether the mutual relationships between individual life history and social group dynamics are species-specific, a general function of social complexity, or universal in all social insects. Thus, we plan on drawing contributions from across the entire spectrum of social insects.
2. Origins & transitions: A model clade approach for social evolution
Rajendhran Rajakumar, University of Ottawa
Arjuna Rajakumar, McGill University
A handful of model organisms have been the bedrock for understanding in detail the life history traits of social insects. More recently, advances in phylogenetics, molecular genetics, various omics, and other disciplines have enabled us to establish a model clade comparative approach to elucidate, at high resolution, transitions in traits and their underlying mechanistic basis across social evolution. This approach has already made a major impact in our understanding of the origin and evolution of several hallmark social insect traits including supergenes, morphological diversification, endosymbiosis, chemical communication, and superorganismal regulation. We are moving from a time of understanding 'how things work' to 'how things change', and ultimately, the model clade approach will form a framework for us to understand how adaptive traits in social insects have originated and radiated, giving rise to the incredible diversity of social organisms. As Tschinkel & Wilson wrote: ‘The story of any species chosen at random is an epic, filled with mysteries and surprises that will engage biologists for generations to come.’ With the promise that the model clade brings to our social insect community, we hope that by expanding this vision to a broader taxonomic scale, we will begin to understand how the mysteries and surprises of these epics evolved.
3. Major transitions revisited: The how, why, and when of social transitions in insects
Seirian Sumner, University College London
Amy Toth, Iowa State University
Sandra Rehan, York University, Canada
The evolution of biological complexity is often explained using the framework of major evolutionary transitions (METs). Social insects have featured as popular study organisms for this, especially the complex societies of the honeybee, most ants, and the vespine wasps, which epitomize the major transition to sociality, as superorganisms. Recently, the wider diversity of insect societies across different lineages has provided important insights into the process of the MET, in providing putative snapshots at different time points of the transition from solitary to complex social living. This very diversity has fueled controversy over the definition and nature of METs, obscuring progress toward a more salient understanding of the underlying proximate and ultimate processes. This symposium will address these issues in three ways. (i) HOW do METs arise: what are the genomic mechanisms involved and what can physiological, morphological, and behavioral traits tell us about the processes? (ii) WHY do METs arise: what does theory tell us about the evolutionary drivers, and what is the empirical evidence for drivers such as inclusive fitness and ecology? (iii) WHEN did METs arise: how does phylogenetic history explain the emergence of sociality and the timing of key innovations during the MET? The latest theoretical and empirical progress across bees, wasps, ants, and termites will be explored through talks and a panel discussion, culminating in a balanced synthesis of the important contribution made by social insects to a fundamental evolutionary question on the nature of the complexity of life.
4. What can we learn from simple insect societies?
Abel Bernadou, Universität Regensburg
Romain Libbrecht, Johannes Gutenberg Universität Mainz
Yasukazu Okada, Tokyo Metropolitan University
Division of labor is a distinguishing feature of insect societies. A classical approach to study behavioral and reproductive specialization in social insects is to compare morphologically distinct castes. Although such comparisons have been key to understanding division of labor and colony functioning as a whole, they are limited by the fact that castes differ in many interrelated traits. For instance, in several species, queens and workers vary in reproduction, but also in size, behavior, immunity, and longevity, thus making it difficult to disentangle the relative influence of each trait. In recent years, there has been a surge in the use of organisms without a morphological reproductive caste to circumvent these issues. These simple societies allow researchers to experimentally induce phenotypic variation, which is a powerful tool to identify and confirm the role of specific regulators of behavioral and reproductive specialization. Within this symposium we seek to highlight and discuss the use of these societies to understand the mechanisms that favor individual specialization and ultimately shaped the evolution of division of labor in eusocial insects. We aim at generating cross-talks beyond the eusocial Hymenoptera, and welcome contributions from a variety of study organisms (e.g., burying beetles, earwigs, etc.) using diverse approaches (e.g., modelling, behavioral analyses, genomics, and transcriptomics, etc.).
5. Spatial structure and organization within social insect colonies
Matina Donaldson-Matasci, Harvey Mudd College
Elva Robinson, University of York, UK
Scott Powell, George Washington University
Spatial structure is integral to the collective organization of social insect colonies, and it is produced by the interplay between internal organizational mechanisms and external environmental interactions. In many species, individuals show spatial fidelity to specific zones within the nest, which interacts with external environmental pressures to influence task allocation and determine the flow of products and information. The location and geometry of nest entrances can influence foraging dynamics and collective defense behavior, while also being an adaptive response to environmental opportunities and pressures. In polydomous (multi-nest) ants, the spatial location of nests and the pathways connecting them to each other determines how quickly and efficiently nutrients and colony members flow through the colony, and how robust that traffic is to disturbance. In turn, the spatial structure of nests and within-colony nest networks is a result of self-organization influenced by biotic and abiotic environmental limitations and interactions. New tools for quantifying nest and network architecture, and for tracking individual movement within and between nests, are increasingly adding a more detailed picture of colony structure and dynamics. The combination of a diversity of approaches holds potential to uncover new connections between within-colony spatial structure and collective organization, as shaped by ecological interactions.
6. Division of labor in social insects: Advancing theory and novel empirical approaches
Ricarda Scheiner, Universität Würzburg
Guy Bloch, The Hebrew University of Jerusalem
Samuel Beshers, University of Illinois at Urbana-Champaign
Sean O'Donnell, Drexel University
Division of labor is a hallmark of all social insects and important for understanding the function and evolution of insect societies. It is also of enormous interest to biologists in other fields, and to computational scientists and engineers who look to social insects for both fundamental problems in need of solutions and biologically inspired approaches to human-designed systems. Studies on the mechanisms and regulation of division of labor are crucial for understanding their social organization and evolution. These systems provide excellent models for understanding the interplay between the intricate social organization of insect societies and the complex internal and developmental mechanisms that shape the structure and behavior of individuals in the colony. We have gathered a diverse group of speakers, including some of the best-known experts in the field of social insects from across the globe, who will present their latest findings on a broad range of social insects including ants, termites, wasps, and bees, as well as social aphids. Our speakers will present state of the art experimental and theoretical research on the fundamental mechanisms underlying all forms of division of labor in a broad variety of social insects, spanning broad levels of biological organization from the regulation of gene expression to neuroendocrine modulation of tissues and social regulation of behavior. This symposium will feature new insights and the latest developments in the field. We expect it to stimulate vigorous and productive discussion and to be of great interest to all IUSSI members.
7. Sociable arthropods: Broadening conceptions about social insects
Miriam Richards, Brock University
Javier Quezada-Euan, Universidad Autónoma de Yucatán
Joël Meunier, Université de Tours
To many entomologists, the term social insect usually means eusocial insect and is applied specifically to species living in structured societies exhibiting the classic, familial division of labor between reproductive castes. In contrast, the term social animal encompasses species with a much broader range of behavioral interactions, including extended parental care, transitory versus permanent group-living, territoriality, etc. Many sociable arthropods are facultatively social, making them ideal models for investigating ecological benefits and costs of solitary versus social reproduction. They also frequently live in groups composed of non-relatives, providing evidence for evolutionary routes to arthropod sociality based on direct fitness benefits. In this symposium we aim to bridge the gap between social insects and social animals, focusing on recent research on the social behavior of non-classical sociable arthropods. We will compare species with vastly different life histories, representing multiple evolutionary origins of sociality, including spiders, bees, caterpillars, earwigs, and aphids.
8. Guests of social insects
David Nash, University of Copenhagen
Og DeSouza, Federal University of Viçosa
The colonies of social insects provide a concentration of resources, often in a well-defended nest. Hence, it is not surprising that various symbiotic species (sensu DeBary) have evolved to exploit these resources, ranging from pure parasites to mutualists and everything in between. This symposium will focus on the enormous variety of guests found in social insect nests, examining the proximate and ultimate drivers of heterospecific cohabitation. While myrmecophiles (ant guests) and termitophiles (termite guests) are the best known examples, mellitophiles (bee guests) and sphecophiles (wasp guests) are also known. We will aim to bring the study of all these guests of social insects together, and to examine common problems, methods and concepts in fields that are often disparate.
9. Advances in collective behavior using quantitative behavioral tools
Laurent Keller, Université de Lausanne
Tomas Kay, Université de Lausanne
Ebi Antony George, National Centre for Biological Sciences, India
Nitika Sharma, University of California Los Angeles
Chris R. Reid, Macquarie University
Daniele Carlesso, Macquarie University
Michael L. Smith, Auburn University
Eusocial insects exhibit prime examples of collective behavior: they select the best food resource or nesting site among many options, build sophisticated structures, and form complex networks to transport resources. The emergence of collective phenomena has long attracted researchers in physics, biology, and engineering. For decades, technological limitations constrained behavioral observation to isolated environments or to short periods of time. Recent advances in computational tools allow researchers to gain detailed observations of multiple individuals over long timescales. We can now access information about interaction networks, information flow, and individual movements that span the entire lifespan of colony members. Computational models can simulate complex physical phenomena, such as the diffusion of chemical signals, and mechanical adaptations of active networks. The (unprecedentedly) large behavioral data sets acquired, often combined with network-based analyses, allow us to experimentally probe the selective pressures guiding social structures, the mechanistic underpinnings of division of labor, and the relationships between social structures and various aspects of individual biology. In our symposium, we present recent advances in the study of collective behavior in social insects. The speakers will discuss the importance of an interdisciplinary approach, with a strong focus on novel technologies such as automated tracking, posture estimation, network analysis, etc., to promote a deeper understanding of collective behavior. The symposium will include a panel discussion on the benefits and drawbacks of implementing these tools on varied experimental set-ups involving different model organisms, with a focus on making them accessible to all researchers.
10. The function of network structure: From genes to ecological communities
Noa Pinter-Wollman, University of California Los Angeles
Graham J Thompson, Western University, Canada
Claire Morandin, Université de Lausanne
Deborah M. Gordon, Stanford University
The structure and organization of networks can influence the function of a biological system. We can extend the use of social network analysis to study key features in social insect biology, including gene networks, protein networks, neural networks, interactions among workers, networks of foraging trails, or interspecific networks. Our symposium will focus on how network structure, such as degree distribution, topology, connectivity, or modularity, influences network function. Studying networks at different scales of organization creates opportunities for examining feedback across scales that can influence the dynamics of evolution. For example, gene networks regulate protein networks, which influence the neural networks that underlie behavioral decisions, leading to social interactions among workers that determine colony-level outcomes such as nest structure and foraging trail networks. Colony-level interactions can translate into ecosystem-level interactions among species, for example in pollinator networks. This symposium will highlight recent network approaches used to study the function of systems in social insect biology at any level of biological organization and in different ecological situations from genes to ecosystems. We strive to promote the potential of network science to expand and unify the study of social insets within a common analytical framework.
11. Tiny brains pushing the limits: Cognitive abilities of social insects
Juergen Liebig, Arizona State University
Elizabeth Tibbetts, University of Michigan
Historically, much cognition research has focused on understanding why some vertebrate species have larger brains and more sophisticated cognitive abilities than other vertebrate species. More recently, research on social insect cognition has shown that brain size does not necessarily limit sophisticated cognition. In fact, despite their relatively small brain size, social insects are capable of many apparently complex behaviors previously thought to be found only in vertebrates. One of the first discoveries was Pardi’s 1940s work on linear dominance hierarchies in wasps. More recently, abstract abilities such as numerical sense, concept formation, and transitive inference have been found in bees and other social insects. Some social insects use social learning to master complex tasks, like rolling a ball through a maze for a reward. These and other findings have transformed how we think about cognitive evolution. Our symposium aims to highlight the cognitive abilities of social insects, including but not limited to how selection acts on social insect cognition, how insects acquire sophisticated behaviors via individual and social learning, how social insects use collective intelligence to improve their decision making and how small nervous systems mediate apparently complex tasks. What was previously thought to be impossible for the simple brains of social insects helps us to refine our understanding of what are exclusive vertebrate cognitive abilities.
12. From signaling to sensing: How pheromones modulate social organization
Cintia Akemi Oi, KU Leuven
Philip Kohlmeier, Rijksuniversiteit Groningen
Chemical communication is a key factor for the ecological success of eusocial insects as it enables colonies to efficiently transfer information between colony members and to regulate various aspects of colony life such as reproductive division of labor, task selection of workers, and the initiation of rapid defense responses. The impact of a pheromone on colony organization does not only depend on the dynamics of its release but also on how strongly other colony members respond to this pheromone. Thus, dissecting the function of a specific compound requires the application of a wide range of techniques including (i) analytic chemistry to characterize pheromonal release, (ii) various omics approaches to identify the genetic pathways that regulate the synthesis and release of pheromones, (iii) bioinformatics and neurophysiological measurements to characterize pheromone-ligand interactions, (iv) neurogenetic tools to reveal the molecular mechanisms that regulate the sensitivity of neurons to their ligand and the neuronal circuitries that trigger a behavioral response, and (v) manipulations of the genome or gene expression to establish functional relationships between genes, gene expression, pheromonal release/sensing, and colony organization. In this symposium, we will provide a platform for presenting the current research developments regarding chemical signaling mechanisms, the neurophysiological and genetic underpinnings of pheromone sensing and their impact on colony organization. Through an integration of conceptual and methodological advances of all aspects of chemical communication, this symposium will contribute to fostering novel and innovative views on how colonies are organized and on how sociality evolved.
13. Neurobiology of chemosensation
Daniel Kronauer, The Rockefeller University
Patrizia d'Ettorre, Université Sorbonne Paris Nord
Efficient communication is pivotal for the function of societies. Social insects primarily communicate via semiochemicals, including pheromones. Studies in behavioral and chemical ecology have made strides in understanding this chemical language over the past decades. However, much less is known about how social insects perceive and process chemical messages at the level of the brain. This symposium will focus on recent advances in genomics and neuroscience that have facilitated the first steps towards identifying and characterizing the genes encoding chemoreceptors, as well as the neural circuitry involved in chemical sensing.
14. The sensory ecology of social insect foraging
Sara Leonhardt, Technische Universität München
Johannes Spaethe, Universität Würzburg
Patrizia d'Ettorre, Université Sorbonne Paris Nord
The fascinating interaction among foraging insects and the resources they collect is mediated by numerous signals. For example, flowers lure pollinating bees or wasps via color, pattern, odor and/or shape, and pollinators perceive these signals via visual, olfactory and/or tactile mechanisms. Both ants and bees use various chemical compounds to exchange information on resources. Increasing evidence suggests that insects prioritize specific signals and show context-specific behavioral responses. Within this symposium, we want to elucidate the role of signals and perception in different facets of social insect foraging. We aim to bring together research from different fields, including chemical ecology, neurophysiology, sensory ecology, and foraging behavior.
15. The effects of anthropogenic warming and increasing thermal variability on social insects
Tali Reiner Brodetzki, University of Pennsylvania
Amy Savage, Rutgers University
Clint Penick, Kennesaw State University
In the age of global anthropogenic changes, the world is becoming increasingly hot, dry, and urban. Furthermore, recent studies have shown that climatic variability is increasing, leading to greater unpredictability across all seasons and geographic locations. These direct effects are, at times, exacerbated by the indirect effects of changing resource bases and shifting community composition. Together, these direct and indirect effects of climate change are imposing strong selective pressures on all species. However, social species might exhibit different mechanisms to deal with these environmental changes than solitary species. It is important to understand these dynamics for social insects because they play important roles in a diversity of ecosystems worldwide. Recent data suggests that there are changes in both social insect behaviors and physiology that raise many questions regarding their survival, adaptation, and community composition. In this symposium, we aim to address recent findings on the direct and indirect effects of anthropogenic warming and increasing thermal variability on social insects and to initiate conversations regarding changes in methodology that should be considered when applying climate studies to social rather than solitary insects. This symposium will also provide an opportunity to bring together researchers investigating taxonomically diverse systems (ants, bees, and wasps) as well as researchers investigating the effects of different aspects of anthropogenic warming on social insects.
16. What makes a successful invader? Exploring how genetics, ecological and behavioral factors contribute to the likelihood of invasion by eusocial species
Brock Harpur, Purdue University
Margarita López-Uribe, Pennsylvania State University
Fabio Manfredini, University of Aberdeen
Benjamin Taylor, Purdue University
Some of the most successful invasive insects are highly eusocial Hymenoptera. Consider fire ants, yellowjacket wasps, and (by some accounts) the Western honeybee. Are these species necessarily more invasive than their solitary ancestors and if so, what features contribute to that success? Recent reviews exploring this topic have proposed that phenotypic plasticity, human management, and sex determination systems each differentially contribute to the success of a social insect establishing outside its range. In this session, we propose to explore what genetic, ecological, and behavioral factors makes an insect species more likely to invade?
17. The anthropogenic drivers of social insect invasions
Jérôme M. W. Gippet, Université de Lausanne
Cleo Bertelsmeier, Université de Lausanne
Social insects are among the most damaging invasive animal species worldwide. They represent only ~2% of all insect species, but 57% of invasive insects. They have dramatic ecological consequences (e.g., biodiversity loss, ecosystem degradation) and cost billions of dollars in damages and control annually. Over the last century, the globalization of human activities has accelerated introductions of social insects outside of their native ranges. In parallel, climate change, urbanization, and habitat disturbance might facilitate the establishment and subsequent spread of invasive species. Studying the anthropogenic drivers of social insect invasions is therefore crucial for better management of ongoing invasions, and the prevention of future introductions. The aim of this symposium is to stimulate exchanges and insights about how human activities and their environmental consequences shape social insect invasions by gathering scientists studying invasive ants, wasps, bees, and termites using diverse conceptual and methodological approaches.
18. Ecological and economic impacts of invasive social insects
Elena Angulo, Estación Biológica de Doñana, CSIC, Sevilla
Franck Courchamp, Université Paris Saclay
Invasive non-native species are increasingly recognized as a major driver of biodiversity loss, as well as having tremendous sanitary and economic impacts. Among the thousands of species that can invade new regions, social insects play a particular role, as they are either considered among the most impactful invasive alien species (e.g., five ant species are among the 100 worst invasive alien species of the IUCN, a feat equaled by no other family), or are not even considered as invasive in many parts of the world because of perception biases (e.g., honey bees in North America, despite their demonstrated effect on native pollinators and their pollinated plants). This symposium will present a panel of studies on the impact of invasive non-native social insects belonging to different groups: ants, termites, wasps, hornets, and bees, all of which have shown to be highly problematic worldwide, but with contrasting scientific coverage and public awareness. We will present a series of talks focusing on ecological impacts as well as on economic costs, combining studies embracing a large taxonomic and/or geographic perspective with specific case studies in one country or region. This symposium will provide the audience with a wide spectrum of studies, thereby highlighting the process itself – biological invasions – and their impacts in society and in the environment. We hope this integrated session will help reinforce much-needed awareness and research effort in invasion science on some of the most interesting and impactful species, social insects.
19. Impacts of introduced honeybee populations on plant-pollinator mutualisms in non-managed ecosystems
Keng-Lou James Hung, University of Oklahoma
Diane Thomson, The Claremont Colleges
Joshua Kohn, University of California San Diego
David Holway, University of California San Diego
The western honeybee is one of the best-studied social insects. It is ubiquitous in both managed and natural ecosystems throughout the world due to intentional introduction by humans. Researchers have long recognized that this highly eusocial, super-generalist species may have impacts on ecosystems to which they are introduced; but we still lack a coordinated global effort to quantify how introduced honeybees are influencing the ecology, evolution, and conservation of pollinators and plants in natural ecosystems. The goal of our symposium is to bring together researchers from around the world who have tackled this topic from a diversity of angles and discuss how best to advance the study of this globally important species in the coming years. The unique global distribution and eco-evolutionary impact of the honeybee are inextricably tied to its highly eusocial life history, and thus our symposium will be relevant for all IUSSI members who are interested in how the sociality of insects translates into ecological impacts, especially from the perspective of ecological invaders.
20 A & B. Protecting pollinators and our food supply: Understanding and managing threats to pollinator health (Part A. Managed pollinators & Part B. Wild pollinators)
Jon Harrison, Arizona State University
Karen Kapheim, Utah State University
Hongmei Li-Byarlay, Central State University
Jay Evans, USDA-ARS
Pollinators are declining and/or experiencing increased mortality worldwide. As pollinators are critical for successful cultivation of 35% of the global food supply and required for reproduction of >75% of flowering plants, these threats to pollinator health must be understood and managed. Social insects, including honeybees, bumble bees, and stingless bees are the most important and best-studied pollinators. Yet, recent research has demonstrated that wild pollinators, including other social and solitary bees, are equally effective and important in both agricultural and natural landscapes. Sustaining effective pollination services thus requires understanding how environmental stressors (e.g., pesticides, habitat loss, disease, climate change) impact both managed and wild pollinators. Certain stressors are likely to have similar effects on managed and wild pollinators, but others may have disparate or even opposing effects on different types of pollinators. This symposium aims to bring together researchers working on how environmental factors affect a broad range of social insect pollinators. Part A will focus on managed pollinators and Part B on wild pollinators. Each symposium part will include a panel discussion focused on how to quantitatively assess the relative importance of different environmental stressors, and how government agencies and industry can protect crops and the pollinators critical for our sustainable food supply. After the Part B panel discussion, we will conclude with a discussion open to all.
21. The benefits of human activity on social insect populations
Elizabeth Evesham, Leeson House field studies Centre, UK
We have seen the effects of climate change, farmland management, urbanization and the introduction of invasive species having detrimental effects on social insect populations, such as reductions in population density of the honeybee. However, can such changes in the landscape and climate actually be of benefit to social insect populations? This symposium aims to bring together speakers studying a range of social insect groups with ideas that demonstrate the plasticity of our social insects such they can adapt and thrive in a changing environment. Therefore, the symposium offers opportunities for participants to discuss the wider implications of disturbance on social insect populations and offer ideas on how best to protect them with any current interventions that have been successful.
22. New frontiers in social insect research: The role of citizen science
Cristina Castracani, University of Parma
Rob Dunn, North Carolina State University
Citizen science is the active engagement of citizens in the collection, analysis, and interpretation of data for scientific purposes. While it can increase scientific knowledge, citizen science plays a role at a social, educational, and political level, contributing to raising public awareness and leading to the adoption of more sustainable behaviors. Over the past decades, there has been a rapid increase in the diversity and scale of citizen science: initiatives range from crowd sourcing activities, in which the time and effort of large numbers of people help to solve a problem or analyze a large dataset, to small groups of volunteers, collecting and analyzing environmental data and sharing their findings. When correctly planned and executed, citizen science is a useful approach for scientific research that can be effectively applied to the study of social insects. Together with classical fields like the conservation and monitoring of species or biodiversity assessments, there are new scientific fields where citizen science can be applied such as physiology, ecology, behavior, pest management, parasitology, and sustainable development. The purpose of this symposium is to present recent research on social insects that has successfully integrated citizen science, promoting discussion on best practices that can help the diffusion of this approach.
23. Balancing social and ecological information in a changing world
Chelsea N. Cook, Marquette University
Kaitlin M. Baudier, The University of Southern Mississippi
Floria Mora-Kepfer Uy, University of Rochester
Social animals can have multi-level responses to environmental changes. Individuals rely on both social and ecological information to make decisions, the repercussions of which impact group fitness. Social insects offer a unique opportunity to study adaptation to environmental variation and response to novel and unprecedented shifts in their surroundings. Here, we focus on how information is perceived, used, and communicated at multiple levels of biological organization, from genes to societies. This symposium explores how insect societies tackle these environmental changes, whether exploring the mechanisms of adaptive adjustments or in terms of how they confront their limitations.
24. The role of individual variation in collective information processing
Yun Kang, Arizona State University
M. Gabriela Navas-Zuloaga, Arizona State University
Chelsea Cook, Marquette University
Social insect colonies are complex adaptive systems where collective behavior emerging from local interactions determines group survival in dynamic environments. Thus, individual behaviors scale up to colony phenotypes where information processing occurs at the group level. In order to characterize how selection shapes the adaptive value of these collectives, it is important to understand how group-level variation arises from variability at the level of the individual constituents. Our session will discuss how different instances of individual variation (e.g., genetic, cognitive, morphological, etc.) inside social insect colonies may be adaptive for efficient collective information processing, and also when it can instead be an unavoidable liability that must be overcome. We bring together a group of distinguished researchers with great expertise in applying experimental approaches, mathematical models, and theory to study the complex adaptive dynamics of social insect colonies in changing environments. This symposium will provide an effective platform for presenting and discussing current research studies and ideas as well as generating connections and promoting collaboration in an interdisciplinary group of researchers across different universities and career stages.
25. Nutritional dimensions in social insect evolution and ecology
Audrey Dussutour, Université de Toulouse
Lina Pedraza, Universität Regensburg
Enikö Csata, Universität Regensburg
The social lives of social insects hinge on nutrition. And yet, nutritional studies of social insects have long been constrained by the chemical complexity of foods and the physiological complexity of insect consumers. Foragers in social insect colonies must also search for, collect, share, and process foods that meet the diverse and changing nutritional needs of all colony members. This symposium will highlight recent advances toward understanding these nutritional interactions, including 1) visualizing the distribution of ingested resources in social networks with cutting edge resolution (e.g., using proteomics and advanced ant tracking systems), 2) new empirical toolkits for quantifying nutritional niches provided by the emerging field of Nutritional Geometry, 3) novel approaches for quantifying trophic interactions (e.g., stable isotopes and neutral lipid fatty acids), and 4) nutrient processing services of symbionts (e.g. bacteria, fungi, and other insects). We aim for a lineup that integrates across levels of biological organization and includes mostly early career researchers.
26. Biological clocks and social organization
Tugrul Giray, University of Puerto Rico
Jose Luis Agosto Rivera, University of Puerto Rico
Manuel Giannoni Guzman, Vanderbilt University
This symposium will examine individual timing (biological clocks and activities) across social organization. Biological clocks organize all aspects of life at different levels of organization, as recognized recently with a Nobel prize for outlining the cellular circuitry underlying the organismal clock. We would like to understand the role of biological clocks in the transition to social life. In social insect organization, researchers first found the clock elements, and later observed important social regulation of the clock in highly eusocial species. Currently, changes to clock regulation across levels of social organization are under study. We are at an interesting point when many new technologies can be applied for either precisely manipulating the environment the organisms are exposed to, or continuously following up to thousands of individuals in their environment and society. Across research groups working all over the world, the technologies and insights are distinct, focused on different levels of organization, neural pathways, genomic mechanisms, and behavior. IUSSI presents the unique opportunity to bring all these insights together and to form collaborations and insights not otherwise possible.
27. Diversity and evolution of termite breeding systems
Kenji Matsuura, Kyoto University
Robert Hanus, Academy of Sciences of the Czech Republic
In social insect colonies, which are based on altruistic behavior towards close relatives, kin structure is a central factor determining social behavior among individuals. There is huge variation in the breeding system of termites both within and among species, which provides us an important clue to understand the ecological and evolutionary factors driving the variation of breeding systems in social insects. Most termite colonies are founded by a monogamous pair (primary king and queen). Some of them remain in the state of simple families throughout the colony life cycle, while in others, the primary king and queen get replaced by secondary (neotenic) reproductives, which leads to an inbred genetic architecture. Yet some others may be co-founded by multiple individuals or by colony fusion, which increases genetic diversity within the colony. Moreover, recent studies have identified asexual queen succession (AQS) in multiple lower and higher termite species and even obligately asexual species. In this symposium, we will share the latest information on the diversity of termite breeding systems and discuss the selection factors, preadaptations, caste-determining mechanisms, and colony interactions that underlie them. The symposium will also cover recent advances in the field of termite queen primer pheromones and king/queen recognition pheromones, which are vital for the establishment and maintenance of different breeding systems.
28. Developmental plasticity of social insectsD
Eva Schultner, Universität Regensburg
Ehab Abouheif, McGill University
Jan Oettler, Universität Regensburg
Superorganismality is characterized by distinct castes, which are obligately co-dependent and of which one is mated for life. Despite the fundamental importance of reproductive division of labor for social evolution, not much is known about the underlying developmental biology. Five different forms of reproductive constraints in workers have been identified, which render workers effectively sterile to different degrees. While some species show flexibility in developmental outcomes (e.g., Apis, Polistes, Platythyrea), others seem to be hardwired in their developmental trajectories (e.g., Cardiocondyla, Monomorium). On the molecular side, studies have emphasized the importance of JH and insulin-like signaling, but how these mediators are integrated into the developmental program remains elusive. Furthermore, recent studies of imaginal disc development have highlighted the co-dependency of modular anlagen in the development of alternative castes. In this symposium we want to shine light on recent advances concerning the molecular and developmental mechanisms of caste determination and caste differentiation. We aim to bring together the fields of classic evo-devo and molecular evolution for a better understanding of the factors mediating the development of castes.
29. Exploring the intricacies of relationships between social insects and microorganisms
Marielle Postava-Davignon, Virginia Wesleyan University
Tatsuya Inagaki, Tokyo Institute of Technology
Hiroyuki Shimoji, Kwansei Gakuin University
Social insects have a variety of symbiotic relationships with microorganisms, ranging from mutualistic endosymbionts and fungus gardens, to the beneficial or pathogenic/parasitic microbes present in their surrounding environment. Microbial mutualists strongly affect the fitness of host organisms by modifying nutritional status, life cycle, physiological and/or behavioral traits in a wide range of taxa. In the environment, social insects promote a wider diversity of soil microflora in many cases, while in the contents of their nests those same microbes are greatly reduced to protect the colony from pathogens. Microbes have not only shaped the evolution of social insects but are deeply connected to maintaining their current social systems. For several decades our understanding of these communities and interactions were restricted to those microbes we could culture in the lab. Recently, molecular approaches have opened many biological functions of symbiotic microbes. Moreover, high-throughput DNA sequencing technology has revealed a number of microbial communities, from the gut to external environments. Despite access to these tools, many of these communities and their interactions have remained unexplored. This symposium aims to share what we know so far and open discussion for how we can expand this area of research in years to come.
30. The high cost of communal living: Evolution and mechanisms of social immunity in eusocial insects
Juliana Rangel, Texas A&M University
James Nieh, University of California San Diego
Amy Geffre, University of California San Diego
Edward Vargo, Texas A&M University
Jordan Twombly Ellis, Texas A&M University
Kin selection theory predicts that altruistic behavior will evolve if inclusive fitness benefits to the actors outweigh its costs. In eusocial insects, kin selection has led to the evolution of altruistic behaviors among colony members, including the cooperative rearing of young by non-reproductive workers, which helps increase a colony’s inclusive fitness. Other forms of altruism include adaptive suicide in the context of colony defense, as well as self-removal of individuals whose presence in the nest may be harmful to the colony. Another strategy to protect a colony’s inclusive fitness is known as social immunity. Social immune responses result from the cooperation of group members to combat the increased risk of disease transmission that arises from group living, including defense strategies to reduce parasite and pathogen infection intensity and transmission among colony members. In this symposium, we will highlight the latest international research that tests the hypothesis that social immune strategies are employed by various eusocial insects to decrease the costs of group living and increase their inclusive fitness. Using examples from various groups including ants, bees, wasps, termites, and aphids, we will broaden our understanding of the potential social immunity strategies that are used by eusocial insects to overcome the costs of communal living. We will end with a panel discussion led by the organizers and symposium speakers, which will shed light on the limitations of testing the predictions of social immunity hypotheses in different study systems, helping to move this field forward in the coming years.
31. My parents made me do it: Epigenetic inheritance in social insects
Christina Grozinger, Pennsylvania State University
Ben Oldroyd, University of Sydney
Social insects display many phenotypes that are clearly the result of epigenetic inheritance and long-term epigenetic modifications. These phenotypes include caste differentiation, temporal polyethism within worker castes, pheromone regulation of adult behavior and physiology, colony-level effects during pre-adult development which influence adult behavior, intragenomic conflict mediating social behavior, and transgenerational immunity. In mammalian and plant systems, DNA methylation is a key mechanism underpinning epigenetic modifications and long-term variation in transcriptional processes. However, in social insect systems, despite the presence of a full suite of DNA methylation enzymes and heritable patterns of DNA methylation across generations, there is little evidence that DNA methylation plays an important role in generating these phenotypes. In this symposium, we will explore the diversity of these phenotypes and examine the underlying molecular mechanisms, including the role of small RNAs, chromatin structure, and gene regulatory networks, and discuss the potential functions of DNA methylation. This symposium will provide the opportunity for the community to compare examples of epigenetic inheritance across life stages, behaviors, and species, reassess the role of DNA methylation and evaluate additional mechanisms, and inspire new research directions and collaborations..
32. Pleiotropism and neofunctionalization: The varied facets of juvenile hormone in social insect life cycles
Klaus Hartfelder, Universidade de São Paulo
Judith Korb, Universität Freiburg
Juvenile hormone (JH) is a key endocrine regulator of insect development and reproduction. Over the past 50 years its crucial role in social insect life histories has gradually come to light. In the Ovarian Groundplan Hypothesis, and subsequently the Reproductive Groundplan Hypothesis, JH has been mechanistically implicated in the evolutionary progression from a solitary lifestyle towards a social one, marked by the splitting of tasks between the reproductive and the subfertile or sterile castes in the Hymenoptera. In the hemimetabolous termites, JH has, originally, primarily been implicated in the differentiation of the soldier caste. Recent progress in our understanding of the molecular basis of JH signaling, as well as comparative studies on the role of JH in hymenopteran and termite caste development and division of labor are now revealing considerable variability in the roles and mechanisms that this hormone plays in different species and social contexts. The aim of this symposium is to bring together the results of current comparative studies on wasp, bee, and termite societies to gain insights on what is common and what is different in the role and mode of action of JH in shaping their societies.
Special symposium: Exhibiting social insect research through art and science communication
Peter Marting, Auburn University
Social insect societies have inspired all of us here on an emotional level, whether from the staggering diversity of beautiful forms and behaviors, the impact they have on whole ecosystems, their intimate relationships with other species, their marvelous architectural achievements, or their ability to transcend individual capacity through collective intelligence. The awe and wonder that insect societies inspire in us often goes beyond the articulation of a peer-reviewed journal article. Piece by piece, we uncover the complex inner workings of these strange societies using rigorous, quantitative tools. The inventiveness and creativity we use to design and conduct experiments should be celebrated and harnessed in the dissemination of our findings – pushing forward with different ways to represent and experience our data. From sculpture, to music, to poetry, to video, using art to explore social insects takes many forms and has many benefits beyond fulfilling expressions that are missing from more traditional scientific outlets. We can gain new insight about hidden patterns in their data by engaging with it using different, non-traditional sensory modalities. Art can be an impactful way to disseminate research to a broader general audience; by providing an engaging narrative of our research, we can allow our audience to make a longer-lasting emotional connection that can not only lead to a more science-literate society, but one that values and actively supports basic research and evidence-based policy. This special symposium is a celebration of social insect scientists and enthusiasts exploring the aesthetics, narratives, and impact of their organisms to reach a deeper understanding and a larger audience.