Behavior Of Social Insects Research Articles

BEECLUST swarm algorithm: analysis and implementation using a Markov chain model

In this paper, we analyse a new swarm search algorithm based on the behaviour of social insects, specifically honey bees. The new algorithm, called BEECLUST, is unique because it does not require any bot-bot communication and does not require the bots to know their position. In this paper, we describe the BEECLUST algorithm and model the algorithm using a birth and death Markov chain. From the Markov model, we answer two questions: 1 Will the bots eventually congregate or cluster near the targets maxima in the search space? 2 How long does it take the bots to cluster? We corroborate the time-to-cluster analysis with laboratory measurements. The experimental results were done with epuck robots in two different search spaces. In general, the BEECLUST algorithm shows promise for using very simple bots in swarm search applications if conditions during the search allow for bot-bot collisions near the target.

Ant-inspired Decentralized Task Allocation Strategy in Groups of Mobile Agents

This paper presents a hybrid task allocation strategy for decentralized groups of mobile agents. The work is strongly inspired by the biological behavior of social insects. Agent based modeling approach has been used to model the behavior of agents. Environment of the model comprises of set of tasks and heterogeneous groups of mobile agents. Each group of agents follows respective local rules to communicate with neighboring agents and with the environment in their vicinity. The agents can not only carry out their own tasks but can also switch tasks to meet colonial demands. This paper presents an extension of a series of models presented earlier. In earlier models, agents reacted only to stimulus. Although evidence exists of task preferences among castes (bias) in many ant species, little work has been done in investigating the benefits for the colony of such preferences. This paper addresses the role of bias in the colony performance under different environmental circumstances. Experiment results indicate that the model presented in this paper is highly efficient, accurate and consistent with biological equivalents. The model with bias within a group is novel and has not been done before to the best of my knowledge.

A Bio-Inspired Resource-Saving Approach to Dynamic Client-Server Association

This novel method for client-server association draws inspiration from the nest-building behavior of social insects. It focuses on reducing active, and thus resource-consuming, servers.

Insulin Modifies Honeybee Worker Behavior.

The insulin signaling pathway has been hypothesized to play a key role in regulation of worker social insect behavior. We tested whether insulin treatment has direct effects on worker honeybee behavior in two contexts, sucrose response thresholds in winter bees and the progression to foraging by summer nurse bees. Treatment of winter worker bees with bovine insulin, used as a proxy for honeybee insulin, increased the bees’ sucrose response threshold. Treatment of summer nurse bees with bovine insulin significantly decreased the age at which foraging was initiated. This work provides further insight into the role of endocrine controls in behavior of in honeybees and insects in general.

Inspired Social Spider Behavior for Secure Wireless Sensor Networks

Last year’s biologically inspired systems had received a great interest. Behavior of social insects, DNA computation, artificial neural networks, evolutionary computation, and artificial immune systems are some of the interests which can be highlighted. Wireless sensor networks have no clear line of defense and no fixed infrastructure; therefore, the known security techniques used for cabled networks might not work perfectly. While wireless sensor networks, node misbehavior can cause the packet dropping, packet modification, packet misrouting, selfish node behavior, and so on. A biologically-inspired algorithm for detecting misbehaving nodes in a wireless sensor network is presented. Such an algorithm, inspired by the behavior of some social spiders from Congo, a specially their strategy to collaborate for detecting an intrusion in their web.

The regulation of ant colony foraging activity without spatial information.

Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

Isolation and characterisation of microsatellite loci in the wasp Mischocyttarus cassununga

Mischocyttarus cassununga, a primitively eusocial Brazilian wasp, commonly found in urban environments, is an interesting model for studies on the evolution of social behaviour in hymenopteran insects. In this study, we constructed a microsatellite-enriched genomic library and presented primers for 18 microsatellite loci. For the analysis, 20 unrelated females were screened and all loci obtained were polymorphic. PCR amplification revealed from 3 (Mcas5b) to 17 (Mcas53b) alleles per locus (\( \overline{x} = 8.3 \)). We detected the levels of observed (Ho) and expected (He) heterozygosities ranging from 0.150 to 0.950 and 0.261 to 0.920, respectively. The polymorphic information content ranged from 0.238 to 0.915, averaging 0.680. All loci were in Hardy–Weinberg equilibrium and linkage disequilibrium was not detected after sequential Bonferroni correction (P > 0.05). These molecular markers will allow further studies on sociogenetic structure, extensive population genetic analysis and diversity of M. cassununga and other Mischocyttarini species.

The Role of Anchor-Tipped Larval Hairs in the Organization of Ant Colonies

The spatial organization within a social insect colony is a key component of colony life. It influences individual interaction rates, resource distribution, and division of labor within the nest. Yet studies of social insect behavior are most often carried out in artificial constructions, which may change worker behavior and colony organization. We observed how workers of the ant Pheidole rhea organized brood in nests with deep chambers and textured walls that were designed to mimic their natural constructions more closely. Instead of clumping larvae into piles on the chamber floor, workers suspended fourth-instar larvae from the vertical walls and ceiling of each chamber while young larvae and pupae were clumped at the base. Fourth-instar larvae possess five rows of anchor-tipped hairs on their dorsal side, and we predicted that these hairs functioned to attach larvae to the nest walls. We gave larvae “haircuts,” where only the anchor-tipped hairs were removed, and then tested their ability to adhere to a textured surface raised to an angle of 90° and then 120° with respect to the horizontal plane. Larvae whose hairs had been clipped came unattached in almost all trials, while larvae whose hairs remained intact stayed attached. This confirmed that anchor-tipped hairs functioned to attach larvae to the walls of the nest. The presence of anchor-tipped hairs is widespread and has been documented in at least 22 genera from the ant subfamily Myrmicinae, including species that occur in a variety of environments and represent a broad range of nesting habits. Based on our results, it is likely that many species exhibit this larval hanging behavior, and this could impact colony characteristics such as spatial organization and the care of developing larvae by nurse workers.

Regulation of the brain dopaminergic system by juvenile hormone in honey bee males (Apis mellifera L.)

Dopamine (DA) and juvenile hormone (JH) are multifunctional regulators of behaviour in social insects, with distinct effects across species and even between different dominance positions within the same species. We examined the effects of JH on the brain dopaminergic system in honey bee males to investigate the potential relationship between JH and DA within Apis mellifera. Both DA content and the expression of three DA receptor genes (Amdop1, Amdop2 and Amdop3) increased in the male honey bee brain from day 4 to day 8 after emergence. Treatment of 4-day-old males with a JH analogue (methoprene, JHA) enhanced brain DA levels. Brain expression of Amdop1 was also enhanced by JHA but not by a DA receptor agonist 2-amino 6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (6,7-ADTN), indicating that Amdop1 up-regulation was not mediated by increased DA receptor stimulation. Furthermore, Amdop1 expression was still enhanced when JHA was co-applied with the DA receptor antagonist cis-(Z)-flupenthixol. Expression levels of Amdop2 and Amdop3 were not altered by JHA, 6,7-ADTN or by JHA plus the DA receptor antagonist. Regulation of the brain dopaminergic system by JH, as observed in solitary species, is conserved in male honey bees but not in female honey bees and other advanced eusocial insects.

Social Hybridogenesis in the Clonal Ant Cataglyphis hispanica

With a few rare exceptions, the vast majority of animals reproduce sexually. Some species have, however, evolved alternative modes of reproduction by shifting from classical bisexuality to unorthodox reproductive systems, like parthenogenesis, gynogenesis, or hybridogenesis. Under hybridogenesis, both the maternal and paternal genomes are expressed in somatic tissues, whereas the germline is purely maternal. Recently, a form of hybridogenesis at the level of the society has been reported in some ants, where purebred females develop into reproductive queens and interlineage hybrids into sterile workers. Here, we report a unique case of social hybridogenesis in the desert ant Cataglyphis hispanica. Workers are produced exclusively from interbreeding between two distinct genetic lineages, whereas male and female sexuals are produced by asexual reproduction through parthenogenesis. As a consequence, all workers are pure hybridogens, and only maternal genes are perpetuated from one generation to the next. Thus, queens of C. hispanica use sexual reproduction for colony growth, whereas they reproduce asexually through parthenogenesis for germline production.

Identification of differentially expressed genes from adult cockroach females exhibiting maternal care behavior

Recent challenges in the study of animal behavior are to detect genes related to behavior and how the genes exert their influence on morphological and behavioral plasticity, particularly as related to the mechanism of insect sociability. In this study, we discovered genes related to parental care behavior in social insects. Woodroaches of the genus Cryptocercus provide nutritious materials and symbiotic protists via proctodeal feeding to their young during early developmental stages. Thus, they are a good model species for discovering genes related to parental care behavior. We screened eight differentially expressed genes (DEG1–DEG8) from adult Cryptocercus females exhibiting maternal care behavior. Of the proteins translated from the screened genes, DEG7 showed high homology to apolipophorin-III-like proteins. Analysis of diverse molecular features revealed that DEG7 was a partial clone encoding apoLp-III, which plays essential roles in hemolymph-lipid transport processes in insects. Isolation of full-length cDNAs for the DEGs identified in this study would be very helpful for a functional annotation of the individual genes and further understanding of maternal care behavior at the molecular level in the future.

Physiological state influences the social interactions of two honeybee nest mates.

Physiological state profoundly influences the expression of the behaviour of individuals and can affect social interactions between animals. How physiological state influences food sharing and social behaviour in social insects is poorly understood. Here, we examined the social interactions and food sharing behaviour of honeybees with the aim of developing the honeybee as a model for understanding how an individual's state influences its social interactions. The state of individual honeybees was manipulated by either starving donor bees or feeding them sucrose or low doses of ethanol to examine how a change in hunger or inebriation state affected the social behaviours exhibited by two closely-related nestmates. Using a lab-based assay for measuring individual motor behaviour and social behaviour, we found that behaviours such as antennation, willingness to engage in trophallaxis, and mandible opening were affected by both hunger and ethanol intoxication. Inebriated bees were more likely to exhibit mandible opening, which may represent a form of aggression, than bees fed sucrose alone. However, intoxicated bees were as willing to engage in trophallaxis as the sucrose-fed bees. The effects of ethanol on social behaviors were dose-dependent, with higher doses of ethanol producing larger effects on behaviour. Hungry donor bees, on the other hand, were more likely to engage in begging for food and less likely to antennate and to display mandible opening. We also found that when nestmates received food from donors previously fed ethanol, they began to display evidence of inebriation, indicating that ethanol can be retained in the crop for several hours and that it can be transferred between honeybee nestmates during trophallaxis.

Collective search and decision-making for target localization

In this article we investigate the properties of collective search and decision-making in robotic swarm, inspired by a phenomena witnessed in bio-societies. The task of the proposed robotic swarm, comprising scouts and labourers, is to find the most hazardous target in a predefined area. Since in the proposed scenario the time interval for decision-making is predefined, robotic scouts have to detect targets within a particular amount of time. Hence, in the first part of the article, we define a model of scout movement that enhances the explored area. As we want to keep the searching process as simple as possible, and at the same time to mimic social insect behaviour, a particular type of correlated random walk is used for exploration. The second part of the article deals with modelling of the decision-making process in the robotic swarm. Using random walk theory we determine under which circumstances all agents (or a particular number of them) would be committed to the most hazardous target at the moment when the predefined time interval for decision-making expires.

Brain development in an insect with extensive maternal care, the tsetse fly Glossina morsitans (Diptera: Glossinidae)

Brain development in an insect with extensive maternal care, the tsetse fly Glossina morsitans (Diptera: Glossinidae)

A review on self-destructive defense behaviors in social insects

Colony defense is a necessary but dangerous task for social insects, and nest defensive behaviors often lead to a premature death of the actor. As an extreme form of colony defense, self-sacrificial behaviors have evolved by kin selection in various social insects. Most self-sacrificial defensive mechanisms occur in response to an acute threat to the colony, but some behaviors are preemptive actions that avert harm to the colony. Self-sacrifice has also been observed as a form of preemptive defense against parasites and pathogens where individuals will abandon their normal colony function and die in self-exile to reduce the risk of infecting nestmates. Here, we provide an overview of the self-destructive defense mechanisms that eusocial insects have evolved and discuss avenues for future research into this form of altruism.

Reproductive Regulating Pheromones of Queen Ant: A Short and Versatile Synthesis of 3,11-Dimethylheptacosane

Social behavior of insects always fascinates human beings as they appear to maintain good order and communication in the society. Insects have developed sophisticated chemical communication systems using their pheromones for the purpose. Among the pheromones, cuticular wax is used to recognize group members from non-members. In ants, there have been identified close to 1,000 cuticular hydrocarbons (CHCs) and the composition of CHCs of cuticles works for the discrimination between their friends and foes. Some species of ants are known to use cuticular wax of the dead ants in other colonies to disguise their identity when they invade other colonies. It was known that the antennae of ants recognize the composition of the CHCs but the exact mechanism of this recognition has not been well studied. The CHCs on the cuticles are also used to distinguish the queen ant from other fertile ants. Queen ants produce 3,11dimethylated linear hydrocarbons longer than C26 (Figure 1). Interestingly, only the odd numbered carbon chains ranging from 27 to 33 are found in insect society. These CHCs are also coated on the eggs of the queen but do not exist on those of other ants, which allow ants to distinguish those eggs and destroy the latter by eating to control their social hierarchy. We became interested in the recognition mechanism of the different composition of CHCs and the effect of the disruption of CHC composition on the social behavior of ants. For these studies, we need to devise a versatile synthetic route to these branched hydrocarbons. Herein, we report the first synthesis of 3,11-dimethylheptacosane (1) through a short and versatile synthetic route. The synthetic analysis of 3,11-dimethylheptacosane (1) shows that intermolecular enyne metathesis can allow to introduce two methyl group on the chain and the overall chain length could be controlled by using an alkyne with proper chain length (Scheme 1). Two methyl groups of 1 can be obtained from two conjugated dienes of 2. These two diene fragments, 3 and 4, can be prepared through enyne metathesis of tosylated butynol 6 with proper olefin. This synthesis would not require any protecting group and allows that alkyne 5 could be replaced by other alkynes with different chain length for the synthesis of all possible CHC pheromones. The synthesis started from 3-butynol to produce the corresponding tosylate 6. The alkyne 6 was treated with the second generation Grubbs catalyst (Grubbs II) under ethylene atmosphere to produce diene 3. Since allyl bromide was not

Ants use pheromone markings in emigrations to move closer to food-rich areas

Nest site quality can affect survival and reproduction, and thus many animals have evolved behaviors which facilitate nest site assessment and selection. Ants of the genus Temnothorax have been shown to include an array of nest site attributes when choosing such a site. Here, we show that they also include traits of the habitat surrounding nest sites. In particular, we found that during emigration, ants preferred to move to nests located close to a previously explored food-rich area. We also determined that scent markings played a role in this choice and that scouts and transporting ants may have tracked scent marks laid in foraging, and this behavior could have biased emigration toward nests located near previously foraged areas. These results indicate that pheromones play a bigger role in Temnothorax foraging and decision making in emigration than previously thought. Overall, this work provides new insights into the mechanisms involved in habitat selection in ants and contributes to our understanding of collective behavior in social insects in general.

Rhythmic behavior of social insects from single to multibody

Revealing the evolution of well-organized social behavior requires understanding a mechanism by which collective behavior is produced. A well-organized group may be produced by two possible mechanisms, namely, a central control and a distributed control. In the second case, local interactions between interchangeable components function at the bottom of the collective behavior. We focused on a simple behavior of an individual ant and analyzed the interactions between a pair of ants. In an experimental set-up, we placed the workers in a hemisphere without a nest, food, and a queen, and recorded their trajectories. The temporal pattern of velocity of each ant was obtained. From this bottom-up approach, we found the characteristic behavior of a single worker and a pair of workers as follows: (1) Activity of each individual has a rhythmic component. (2) Interactions between a pair of individuals result in two types of coupling, namely the anti-phase and the in-phase coupling. The direct physical contacts between the pair of workers might cause a phase shift of the rhythmic components in individual ants. We also build up a simple model based on the coupled oscillators toward the understanding of the whole colony behavior.

Rossiter Henry Crozier 1943 - 2009

Ross Crozier, population geneticist and leader in the study of the evolutionary genetics of social insects, was born on 4 January 1943 in Jodhpur, India. He died of a heart attack in his office at James Cook University in Townsville on 12 November 2009. He is survived by his wife Yuen Ching Kok, who was his inseparable companion and collaborator in life as in the laboratory. Crozier was a pioneer in the application of molecular genetic markers to the analysis of social insect populations, and generated much of the theory that made these analyses possible. Ross and Ching Crozier produced the first sequence of the honey bee mitochondrial genome?the second insect mitochondria to be fully sequenced. From the sequence Crozier produced fundamental insights into the nature of DNA evolution, particularly directional mutation pressure towards particular nucleotides. Crozier contributed massively to the development of kin selection theory, which remains the most potent explanatory theory for the evolution of social behaviour in insects.

The ‘truck‐driver’ effect in leaf‐cutting ants: how individual load influences the walking speed of nest‐mates

The foraging behaviour of social insects is highly flexible because it depends on the interplay between individual and collective decisions. In ants that use foraging trails, high ant flow may entail traffic problems if different workers vary widely in their walking speed. Slow ants carrying extra‐large loads in the leaf‐cutting ant Atta cephalotes L. (Hymenoptera: Formicidae) are characterized as ‘highly‐laden’ ants, and their effect on delaying other laden ants is analyzed. Highly‐laden ants carry loads that are 100% larger and show a 50% greater load‐carrying capacity (i.e. load size/body size) than ‘ordinary‐laden’ ants. Field manipulations reveal that these slow ants carrying extra‐large loads can reduce the walking speed of the laden ants behind them by up to 50%. Moreover, the percentage of highly‐laden ants decreases at high ant flow. Because the delaying effect of highly‐laden ants on nest‐mates is enhanced at high traffic levels, these results suggest that load size might be adjusted to reduce the negative effect on the rate of foraging input to the colony. Several causes have been proposed to explain why leaf‐cutting ants cut and carry leaf fragments of sizes below their individual capacities. The avoidance of delay in laden nest‐mates is suggested as another novel factor related to traffic flow that also might affect load size selection The results of the presennt study illustrate how leaf‐cutting ants are able to reduce their individual carrying performance to maximize the overall colony performance.