ArticlePDF Available

The guard honey bee: ontogeny and behavioural variability of workers performing a specialized task

Authors:

Abstract and Figures

Guarding is a relatively unstudied aspect of honey bee, Apis mellifera L., worker behaviour. The aim of this study was to characterize quantitatively the ontogeny and individual variability of guarding behaviour, the allocation of workers to the guard population in a colony, and the intercolonial variability of guarding behaviour. Guarding is a discrete task performed by a distinct group of workers that are younger than foragers and older than house bees. Workers that guarded initiated the behaviour between the ages of 7 and 22 days. The mean age of the onset of guarding varied; the minimum mean age of guards for a colony was 13·6 days and the maximum was 16·0 days. Workers varied in the length of time they spent as a guard. Most bees guarded for less than 1 days; however, some guarded up to 6 consecutive days. The more time a bee spent guarding during a day the more likely that bee was to guard for more than 1 day. Bees that guarded for more than 1 day also had longer and more frequent individual guarding bouts. All colonies that were studied had guard populations, but not all workers guarded. A relatively small proportion of any age cohort was observed to guard. The percentage of an age cohort that guarded varied among colonies, as did the size of the guard population. Guarding is a specialized task in that few bees guard, but guarding does not appear to require experience because so few bees remained as guards for very long. There was intercolonial variation in all aspects of the ontogeny of guarding and in allocation of workers to guarding. This variation is discussed in the light of other studies of variation in worker behaviour.
Content may be subject to copyright.
A preview of the PDF is not available
... For some other behaviours, however, age is but one criterion. In particular, guarding and stinging propensities seem to vary between individuals of the same age group [3,4]. It is unknown, however, whether this form of task allocation is a short-term, 'ad hoc' organization possibly controlled by collective signals such as pheromones (i.e. ...
... It is worth noting that this variability was evident even though we specifically tested 'defensive bees' that attacked a black feather waved in front of the hive entrance. This was likely a rather homogeneous population consisting of middle-aged guard bees and maybe older foragers or soldiers [3,4]. Sampling the full spectrum of bees composing the colony (by also catching younger nurse bees for example) would likely make this inter-individual variability even stronger. ...
Article
Full-text available
Whether individuals exhibit consistent behavioural variation is a central question in the field of animal behaviour. This question is particularly interesting in the case of social animals, as their behaviour may be strongly modulated by the collective. In this study, we ask whether honeybees exhibit individual differences in stinging behaviour. We demonstrate that bees are relatively stable in their decision to sting—or not—in a specific context and show temporal consistency suggestive of an internal state modulation. We also investigated how social factors such as the alarm pheromone or another bee modulated this behaviour. The presence of alarm pheromone increased the likelihood of a bee to sting but this response decayed over trials, while the presence of a conspecific decreased individual stinging likelihood. These factors, however, did not alter stinging consistency. We therefore propose that social modulation acts by shifting the stinging threshold of individuals. Finally, experimental manipulation of group composition with respect to the ratio of aggressive and gentle bees within a group did not affect the behaviour of focal bees. Overall, our results establish honeybee stinging behaviour as a promising model for studying mechanistically how collective and individual traits interact to regulate individual variability.
... After spending approximately 21 to 26 days within the hive as brood, the female pupae will be fully developed into immature workers and the male pupae will have developed into drones. The role of the honeybee depends on their age polytheism; a young worker spends their day cleaning the hive and nursing broods, while a forager spends their day harvesting pollen and nectar (Moore et al., 1987;Johnson, 2010). Therefore, natural and predatory death rates cannot be equal in each life cycle stage. ...
Article
Full-text available
Honeybees play a critical role as natural pollinator and are essential to global food production. Monitoring honeybee population densities can provide valuable insights into the environmental status of a given region, although effectively carrying out such monitoring is challenging. To address this issue, this study focused on the development of a mathematical model to predict population density and detect potential colony collapse. The model utilized a set of effective arrays of differential equations that consider crucial parameters. Analyzing actual data using the model revealed that regions with higher flower densities experienced reduced vulnerability to unnatural deaths or diseases, while those with lower flower densities tended to have smaller populations. Furthermore, numerical simulations showed that unnatural death rates exerted the most significant impact on the model. In adverse environmental conditions, forager populations decline first, leading to decreased food availability and potential colony collapse. This model, as a highly practical tool, holds immense value for environmentalists seeking precise predictions of honeybee population density within their respective regions.
... The degree and persistence in time of behavioural variation varies among species, worker groups and tasks that are performed [2][3][4][5][6]. A honey bee (Apis mellifera) might spend only a few hours of her life as a nest guard [7], while a leaf-cutter ant minor worker will show a lifelong dedication to fungus gardening and nursing [5]. Division of labour is similarly diverse and complex in stingless bees (Meliponini), the largest group of eusocial bees [8], yet the social, physiological and molecular mechanisms underpinning division of labour in stingless bees remain poorly understood. ...
Article
Full-text available
Stingless bees are a diverse and ecologically important group of pollinators in the tropics. Division of labour allows bee colonies to meet the various demands of their social life, but has been studied in only ~3% of all described stingless bee species. The available data suggest that division of labour shows both parallels and striking differences compared to other social bees. Worker age is a reliable predictor of worker behaviour in many species, while morphological variation in body size or differences in brain structure are important for specific worker tasks in some species. Stingless bees provide opportunities to confirm general patterns of division of labour, but they also offer prospects to discover and study novel mechanisms underlying the different lifestyles found in eusocial bees.
... . The mandible and its gland, (Mg) mandibular gland, (Rg) reservoir of the mandibular gland, (Se) setae, (Gr) groove; (Lensky & Cassier, 1995 Robinson et al., 1990 ) . Moore et al., 1987 ...
Article
Full-text available
Beekeeping is an important agricultural activity that contributes to increasing agricultural production. Therefore, it has received a lot of attention through the ages. Despite this importance, it is still facing many problems in all countries especially in Iraq. One of the obstacles of honeybee industry development is the aggressive behavior of this beneficial insect. This review examined the complex integration of external stimuli, reactions, and response to olfactory, visual, and mechanical signals. It was concluded that the strength of the colony, its queen health, her production of eggs, and the abundance of food sources, all have a role in determining the aggressiveness of bees. The physiological explanation of this behavior is the secretion of alarming pheromone, isopentyl acetate, which leads to an increase in the level of serotonin and dopamine in the brains of bee workers. Moreover, the location of the olfactory and visual receptors, and the number of sensory cells in the antennae, which varies according to honeybee races, resulted in a complex response of defensive reactions that include guarding, recruiting, alerting, attracting, culminating, biting, stinging, and pursuing.
Article
Resistance to and avoidance of stress slow aging and confer increased longevity in numerous organisms. Honey bees and other superorganismal social insects have two main advantages over solitary species to avoid or resist stress: individuals can directly help each other by resource or information transfer, and they can cooperatively control their environment. These benefits have been recognised in the context of pathogen and parasite stress as the concept of social immunity, which has been extensively studied. However, we argue that social immunity is only a special case of a general concept that we define here as social stress protection to include group‐level defences against all biotic and abiotic stressors. We reason that social stress protection may have allowed the evolution of reduced individual‐level defences and individual life‐history optimization, including the exceptional aging plasticity of many social insects. We describe major categories of stress and how a colonial lifestyle may protect social insects, particularly against temporary peaks of extreme stress. We use the honey bee ( Apis mellifera L.) to illustrate how patterns of life expectancy may be explained by social stress protection and how modern beekeeping practices can disrupt social stress protection. We conclude that the broad concept of social stress protection requires rigorous empirical testing because it may have implications for our general understanding of social evolution and specifically for improving honey bee health.
Article
Why do human beings exhibit enduring personality differences, and to what extent are these differences shaped by biological and cultural evolution? Despite ongoing efforts, a consensus framework remains elusive. This paper introduces the Diversity Advantage Theory, partially shifting the focus from how personality impacts individuals to its influence within groups. Through an evolutionary lens, connections among personality, collective cognition, and group dynamics are explored, revealing that diversity in personality traits would tend to enhance collective intelligence and foster deliberation, mitigating group biases. The framework proposes that biologically evolved psychological mechanisms underlying personality, including individual niche-finding, adapt and conform to culturally evolving heuristic personality traits. This co-evolution stabilized the Big Few personality traits in western, educated, industrialized, rich, and democratic (WEIRD) societies, addressing recurring group challenges related to engagement, closure, task, risk, and change. The Diversity Advantage Theory offers a novel explanatory framework for stable personality traits, aligning with biology and testable in contemporary group contexts. At least three novel perspectives are introduced: (1) personality trait dimensions have emerged, in part, to establish normative behavior for functional group processes; (2) normative diversity along trait dimensions enhances collective intelligence; and (3) such diversity should also promote deliberation, mitigate group biases, and improve group decision-making.
Article
The olfactory system plays a fundamental role in mediating insect behaviour. Worker bees exhibit an age‐dependent division of labour, performing discrete sets of behaviours throughout their lifespan. The behavioural states of bees rely on their sense of the environment and chemical communication via their olfactory system, the antennae. However, the olfactory adaptation mechanism of worker bees during their behavioural development remains unclear. In this study, we conducted a comprehensive and quantitative analysis of antennal gene expression in the Apis mellifera of newly emerged workers, nurses, foragers and defenders using RNA‐seq. We found that the antenna tissues of honey bees continued developing after transformation from newly emerged workers to adults. Additionally, we identified differentially expressed genes associated with bee development and division of labour. We validated that major royal jelly protein genes are highly and specifically expressed in nurse honey bee workers. Furthermore, we identified and validated significant alternative splicing events correlated with the development and division of labour. These findings provide a comprehensive transcriptome profile and a new perspective on the molecular mechanisms that may underlie the worker honey bee division of labour.
Article
In laboratory tests, two inbred lines of honeybees (Apis mellifera) different in colony defensive behaviour were shown to differ in their initial general activity level, the time to react to isopentyl acetate, and the initial intensity of the reaction. Evaluation of an F1 and backcrosses to both lines indicated that a more responsive phenotype was dominant to a less responsive phenotype in all three characteristics. The degree of dominance for time to react was estimated as 0·502 and the heritability as 0·681. It was estimated that 2 or 3 loci controlled each of the three components of behaviour.
Article
1. Observations at hive entrances have been made to ascertain the relative importance of scent and behaviour in enabling a guard bee to recognise members of her own colony and to distinguish them from intruders from other colonies. 2. Guard bees are not present at the hive entrance unless the colony has been alerted. 3. Alerting of colonies is brought about by the presence of robber bees or by numbers of bees that have strayed from other colonies. 4. Guard bees attempt to intercept and inspect other bees on the alighting-board of the hive. Bees of various ages undertake guard duties. 5. Guard bees recognise members of their own colony by scent. 6. Robber bees are recognised by behaviour when attempting to enter the hive, but all other intruders are recognised by scent. 7. After recognition intruders, other than robbers, assume either a dominant or a submissive attitude. 8. A dominant intruder, usually a laden forager, enters the hive without hesitation or difficulty. 9. On interception a submissive intruder stops moving towards the hive entrance and allows herself to be subjected to extensive examination or mauling. 10. Whilst being extensively examined or mauled the submissive intruder offers food to the guards and on their refusal of it 'strops' her tongue. It is suggested that this is a displacement activity. 11. A submissive bee that is being mauled sometimes passes into a state of thanatosis. 12. Very young bees are recognised as intruders and mauled just as readily as older bees. 13. As long as an intruder remains submissive she is not stung by the guards. Intruders, including robbers, which attempt to escape from the guards are immediately seized and stung. 14. If intruders, other than robbers, succeed in remaining in a strange colony for 2-3 hours they are accepted by the bees of that colony.
Article
Within a honey bee (Apis mellifera) colony there are individuals who specialize in the removal of the dead (necrophoresis). Necrophoric behaviour is an essential adaptation to social life in enclosed nests, and the rapidity of corpse removal distinguishes it from general nest-cleaning behaviour. In recognition of a corpse within the nest, worker bees probably use chemical cues appearing very rapidly after the death of a bee; thoroughly extracted or paraffin-coated bees are removed slowly. The bees specializing in necrophoric behaviour comprise one or two per cent of the colony population.
Article
The colony defense strategies of the three honeybee species in Thailand were studied to examine the influence of predation on tropical honeybee societies. Each species focuses its defenses upon different stages in the predation sequence of detection-approach-consumption. This radiation in defense strategies apparently reflects each species' preadaptation by worker size (small, medium-sized, or large) and nest site (cavity or tree branch) to a different pattern of colony defense. Wasps, birds, and primates probably have difficulty finding the small, dispersed colonies of Apis florea, whose nests are built low on the branches of dense, shrubby vegetation. Once found, however, they are easily approached and overpowered because their low, exposed nests are accessible and their small workers inflict relatively painless stings. When overwhelmed, the bees quickly abandon their nest; later, they return to salvage wax. Ants find A. florea nests easily and at least one species (Oecophylla smaragdina) easily kills these small bees. However, sticky bands of resin encircling the nests' slender substrate branches prevent ants from invading A. florea nests. Cavity-nesting colonies of Apis cerana are conspicuous with their medium-sized bees streaming in and out of low, clearly visible entrance holes in caves and hollow tress. However, gaining access to A. cerana nests is difficult. Large predators cannot pass through the small entrance opening and small predators are overpowered by entrance guards. But if a large predator can breach a nest cavity's walls, it faces an only moderately powerful stinging defense. Apis cerana colonies are relatively small and their workers are not fiercely aggressive. Predators easily find the large, sometimes aggregated colonies of Apis dorsata, whose nests hang in the crowns of the tallest forest trees. But only skilled fliers and climbers can reach these lofty nests. Those which do face massive stinging attacks from the large colonies of these relatively giant, ferocious bees. Nests of both open-nesting species, Apis florea and A. dorsata, are protected by a three- to six-layer curtain of bees over the comb. Apis cerana colonies lack these curtains but are protected by their nest cavity walls. A curtain of inactive guards requires a large labor force. The high worker: brood ratio in A. florea relative to A. cerana colonies suggests that the age polyethism schedules of the open- and cavity-nesting species are tuned differently to generate the appropriate proportions of guard bees. Each species' colony defense system consists of numerous interwoven lines of adaptation, including nest site, nest architecture, colony population, labor allocation to defense, age polyethism schedule, colony mobility, and worker morphology, physiology, and behavior. Predation has been a pervasive and powerful force in the evolution of these tropical bee societies.