"All cold-blooded animals and a large number of warm-blooded ones spend an unexpectedly large proportion of their time doing nothing at all, or at any rate, nothing in particular." (Elton 1927) Many animals are remarkably "lazy", spending >50% of their waking hours "resting" . This is common across all taxa, ecologies, and life histories, including what are commonly considered to be highly industrious animals: the social insects (e.g., Aesop's Fable 'The Grasshopper and the Ant'). This dissertation broadly seeks to explain a phenomenon that has long been observed, but never adequately addressed, by asking: 'why are there 'lazy' ants?' First, I established that inactivity was a real and ecologically relevant phenomenon in the ant Temnothorax rugatulus by testing whether inactivity was a lab artifact. I then showed that inactive workers comprise a behaviorally distinct group of workers that are commonly overlooked in studies looking at colony function, though they typically represent at least half of the individuals within social insect colonies. I then tested a set of mutually non-exclusive hypotheses explaining inactivity in social insects: that (1) inactivity is a form of social "cheating" in which egg-laying workers selfishly invest in their own reproduction rather than contribute to colony fitness, (2) inactive workers comprise a pool of reserve workers used to mitigate the effects of fluctuations in colony workload, (3) inactivity is the result of physiological constraints on worker age such that young and old workers may less active due to inexperience/physical vulnerability, and physiological deterioration respectively, (4) inactive workers are performing an as-yet unidentified function, such as playing a role in communication and acting as food stores, or repletes, and that (5) inactive workers represent the 'slow' end of intra-nest variation in worker 'pace-of-life'. Inactivity is linked to worker age, reproduction, and a potential function as food stores for the colony. These hypotheses are not mutually exclusive, and in fact, likely form a 'syndrome' of behaviors common to inactive social insect workers. Their simultaneous contribution to worker inactivity may explain the difficulty in finding a simple answer to this deceptively simple question.

The construction of nests in insect societies requires building materials, pulp and water foragers, builders and also an organized workforce for effective construction. The central hypothesis of this study is that wasp societies developed a social crop, or common stomach, which stores water and provides a mechanism for worker connectivity, which in turn regulates construction behaviour. Inspired by the construction behaviour of social wasps, an agent-based model is presented to show that via the usage of the common stomach, larger colonies enjoy the benefit of having highly effective foragers, while most of the swarm stays on the nest and only a few engage in highly risky foraging trips. We also demonstrate how colony efficiency changes as a function of colony size and the constitution of the labour distribution, as well as how indirect interactions can increase efficiency of labour in wasp societies.

Construction of wasp nests is a self organized process that requires building materials, pulp and water foragers, and builders to cooperate. In this paper we study how the society of agents use a social crop, or common stomach, to store water that also provides a mechanism for worker connectivity, which in turn regulates building. Our model predicts that via the common stomach usage, medium sized colonies enjoy the benefit of having highly effective foragers and this in turn means that the colonies need only endanger a few foragers to ensure steady construction. When pulp foraging becomes more costly than water foraging, the colonies adjust via recruiting more pulp foragers and less water foragers, but keep high numbers of common stomach wasps on the nest. The common stomach provides an adaptable platform for indirect worker connectivity and a buffer for water storage.

BACKGROUND: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. RESULTS: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A.cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. CONCLUSIONS: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory.

Social insect is known for its unique caste system, coherence and effective division of labor, but also for the extreme longevity of reproductive individuals in comparison with asexual castes. Although mechanisms leading to lifespan differences between reproductive and non-reproductive castes of social insects are not sufficiently explained, one of the longevity determinants might be telomere length and activity of telomerase as the most common mechanism of telomere length maintenance. Telomere length belongs to general indicators of organismal lifespan. This work is focused on monitoring of telomerase activity in various stages, castes and organs of the termite Prorhinotermes simplex (Isoptera: Rhinotermitidae) showing up-regulation of telomerase in reproductive castes.

The organization of complex societies requires constant information to flow between individuals. Because of their elaborated social structures and principally because of the division of labor, social insects depend on the efficacy of their information web in order to adapt the colony activity to its needs. Although many studies focused on understanding the regulation of the foraging activity, little is known about the intranidal food distribution and stock management regulation. The aim of this thesis is to quantify and describe the dynamics of the food flow and its regulation in an ant colony. A medical imagery technique, scintigraphy, was adapted to follow the propagation of radio-labeled nutrients inside the nest. This technique allowed spatiotemporal dynamics quantification of the food flow and led to the enunciation of simple yet robust regulation rules that are at work during the colony feeding process.<p>The dynamics of the harvest is regulated by the coupling of a positive and negative feedbacks. The harvest acts as both: negative and positive feedbacks. Entering food-loads trigger foragers to exploit the newly discovered food source through the well-known recruitment process. At the same time, the harvest proportionally reduces the entering food flow until the complete stop of the foraging activity when the colony reaches satiety. Surprisingly, the positive feedback (that is the recruitment) is not responsible for a faster entering food flow and is not influenced by the colony needs while the exploring activity is. The spatial dynamics of the food exchange network revealed stable patterns and fine tuning regulation of the feeding process. Spatial analysis of the food distribution showed that sucrose is heterogeneously stored among individuals and also heterogeneously consumed. We observed a regular spatial structure leading to centralization of the stocks: heavy loaded individuals being at the center of the cluster and weakly loaded individuals at its periphery.<p>The spatiotemporal quantification of the food flow allowed describing and understanding the flexibility of the colony to adapt its working force according to its nutritional requirements.<p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Terraforming mars by autonomous robotic building system, inspired by social insect. Idea design of robotic solution, their transportation and software. Design of structures builded by robots and their function. Pyramidal structures interwoven with ice tunnel, heat the atmosphere of Mars and accumulate heat in their mass. These structures are built with cheap and simple robots that mimic the behavior of social insects.

Social insects are the most dominant terrestrial fauna for the last 50 million years. This tremendous ecological success is accompanied by the fact that sociality has evolved multiple times independently and achieved highest degree of complexity in insect lineages. The remarkable social organization found in insect societies is the result of finely balanced cooperation and conflict among the colony members. A typical hymenopteran colony is characterised by one or a few queens monopolizing reproduction and several sterile workers co-operatively raising brood and performing colony activities. The colonies are often conceptualized as superorganisms where groups of cooperative workers are compared with organs in the body, each of which accomplish a particular task like brood care, foraging and defence. The choice of tasks is often regulated by a systematic age polyethism. As the queens monopolize reproduction, they serve as the sole suppliers of eggs in the colony. Therefore, loss or death of the queen creates a crucial void which exposes the colony to potential reproductive conflict for the position of egg-layer. This crisis is expected to be extreme in monogynous colonies. The situation is rescued only after a new queen is established, and the whole process is known as queen succession. I am interested in this crisis management, and my thesis deals with potential and realized conflicts associated with queen succession and behavioural strategies involved in resolution of these conflicts. The queen can be replaced in two ways - either by a newly eclosed specialized reproductive individual, which happens in highly eusocial hymenopterans, or by an existing member of the colony (worker), as it happens in primitively eusocial hymenopterans. Unlike in highly eusocial species, the workers of primitively eusocial species retain their ancestral capability of mating and activating ovaries to produce both sons and daughters, which makes them suitable for taking up the role of queen in their lifetime. Hence, primitively eusocial species provide a unique situation where loss or death of the queen might result in severe reproductive conflict as the queen can be replaced by any one of the existing workers. Strictly monogynous colonies of the tropical primitively eusocial wasp Ropalidia marginata provide ideal opportunities to study the reproductive conflict and its resolution associated with queen succession because the queen is frequently replaced by one of her nestmates resulting in a serial polygyny. These queens have highly variable tenures of queenship ranging from seven to over 200 days, which, together with the fact that they are replaced by a variety of relatives such as daughters, niece and cousins, suggests a potential reproductive conflict with variable degrees of complexity. I have divided my thesis in three parts which are as follows -Natural queen turnover: Previous works from this lab have tried to characterize the queen succession in R. marginata colonies by experimentally removing the queen from the colony. As this design involves the experimenter intervening at a random point of the colony cycle, the colony might not respond in the similar way as it might have done to a natural succession necessitated by loss or death of the queen. But rarity and unpredictability of natural queen turnovers made them difficult to study. Therefore, in this section, we gathered a dataset of long-term and opportunistic quantitative behavioural observations on eleven natural queen turnovers and compared them with available data on queen removal experiments. All our queen removal experiments resulted in a hyper-aggressive potential queen who gradually reduced her aggression, activated her ovaries and went on to become the unanimously accepted new queen of the colony if the original queen was not returned. Here we found a similar phenomenon in natural colonies where a single un-challenged potential queen took over the colony as new queen after the old queen was lost, died or was driven out of the colony. In some of the natural colonies, the transition was preceded by aggression shown by the potential queens towards their nestmates including the queens, which indicates that they might have pre-empted the transition. The potential queens in natural colonies started laying eggs much faster than in experimental colonies suggesting their physiological readiness for the transition. How does a colony respond to a declining queen?: As we could show that some of the potential queens might perceive the upcoming queen turnover, a fair prediction would be that they sense it through the declining fertility status of the queens. Therefore, we tried to ex-perimentally induce situations where the queen appears to be declining, expecting that it might lead to a queen turnover. The growing evidence suggests that R. marginata queen maintains her status by applying a pheromone on the nest surface by rubbing the tip of her abdomen. We knocked down the nest to deny the queen the surface for applying her pheromone, and argued that the queen would be overthrown as the workers would sense her as infertile. To our surprise, the queen maintained her status in six out of seven colonies by applying her pheromone on the entire surface of the cage. However, the effectively insufficient concentration of pheromone elicited aggression from workers towards the queen, and the queen retaliated back with aggression. These results suggest that the pheromone, being an honest signal of fertility, is extremely important for the queen for maintaining her reproductive monopoly, and the workers are able to perceive the decline of the queen from her pheromone. Queen-successor conflict over access to reproduction: Here we more explicitly looked at the potential reproductive conflict between the queen and her successor over access to direct reproduction. We used the theory of parent-offspring conflict proposed by Robert Trivers (1974) as the conceptual framework and adapted it to unravel the pat-tern of queen-successor conflict in R. marginata colonies. According to this idea, we expected that there should be a pre-conflict zone where the queen and the successor both would agree that the queen should continue to reproduce, followed by a conflict zone where the successor would try to takeover but the queen would hang on, finally followed by post-conflict zone where they both would agree that the successor should reproduce. To test this expectation, we maintained the queen and the potential queen on either side of a wire-mesh partition, each with randomly chosen half of the workers. It allowed the potential queen (successor) to establish herself and then we reintroduced the queen to her side of the mesh daily till the queen gave up. We could behaviourally characterise all three zones which always appeared in the expected sequence. The pre and post-conflict zones had no aggressive interaction between the queen and the potential queen, whereas the conflict zone was characterized by aggressive falling fight between them. This is our first success in experimentally creating overt conflict between the queen and her successor. Overall we can say, that the queens and the potential queens of R. marginata show great behvioural plasticity which might have been shaped by natural selection as an adaptation for conflict resolution. We could show that the potential queens sometimes can predict the upcoming transition and pre-pare themselves accordingly, whereas they can also react to an experimentally created sudden loss of queen by hugely elevating their aggression. The docile queens, on the other hand, maintain their reproductive monopoly by a pheromone, which is essentially a feature of highly eusocial species. But these docile queens have not lost their capability to show aggression and can use that to complement the insufficient concentration of her pheromone. This and the behaviour of potential queens in their establishment phase are strongly reminiscent of typical primitively eusocial species. We conclude that Ropalidia marginata is, perhaps, a particularly advanced primitively eusocial hymenopteran situated on an evolutionary continuum from primitive to highly eusocial species.