Search

European honey bees (Apis mellifera) were first introduced to the Hawaiian Islands in the late 1800s, and are now ubiquitous across the state in both managed and feral colonies. Though they play an important role in pollination services for native plants and agricultural crops, the competitive impacts they may have on native bees are not well understood. We assessed bee interactions on the preferred floral resources of Hylaeus anthracinus at the Ka Iwi State Scenic Shoreline on O'ahu, including Heliotropium foertherianum, Scaevola taccada, and Myoporum sandwicense. Bee visitation frequency and duration were documented and analyzed in one-hour increments from 08:00-13:00 totaling 90 hours of video recordings of the focal plants. Honey bee visitation frequency to H. foertherianum peaked at 11:00, and corresponded with a significant reduction in H. anthracinus visitation that resulted in a bimodal activity distribution for H. anthracinus. Feeding duration of H. anthracinus was significantly reduced when visiting H. foertherianum flowers following a honey bee, but unchanged when visiting after conspecifics. Honey bee feeding duration was unaltered by the species of the previous visitor, indicating that deterrence of H. anthracinus to flowers may not be the result of nectar exploitation. S. taccada and M. sandwicense received low overall bee visitation, prohibiting further analyses. We conclude that the presence of honey bees on a preferred foraging resource results in a temporal niche partitioning of H. anthracinus indicative of interference competition, possibly the result of interspecific chemical cues. Future honey bee management considerations are discussed. Keywords: Apis mellifera, Heliotropium foertherianum, interference competition, nice partitioning, European honey bees (Apis mellifera L.) are present worldwide as a result of purposeful introductions for honey production and agricultural pollination services. While they are more often viewed positively by [...]

Sleep is essential for basic survival, and insufficient sleep leads to a variety of dysfunctions. In humans, one of the most profound consequences of sleep deprivation is imprecise or irrational communication, demonstrated by degradation in signaling as well as in receiving information. Communication in nonhuman animals may suffer analogous degradation of precision, perhaps with especially damaging consequences for social animals. However, society-specific consequences of sleep loss have rarely been explored, and no function of sleep has been ascribed to a truly social (eusocial) organism in the context of its society. Here we show that sleep-deprived honey bees (Apis mellifera) exhibit reduced precision when signaling direction information to food sources in their waggle dances. The deterioration of the honey bee's ability to communicate is expected to reduce the foraging efficiency of nestmates. This study demonstrates the impact of sleep deprivation on signaling in a eusocial animal. If the deterioration of signals made by sleep-deprived honey bees and humans is generalizable, then imprecise communication may be one detrimental effect of sleep loss shared by social organisms. dance language | signal precision | recovery sleep | sleep rebound doi 10.1073/pnas.1009439108

In this study, the effects of ethanol on honey bee social communication and behavior within the hive were studied to further investigate the usefulness of honey bees as an ethanol-abuse model. Control (1.5 M sucrose) and experimental (1.5 M sucrose, 2.5% w/v ethanol) solutions were directly administered to individual forager bees via proboscis contact with glass capillary tubes. The duration, frequency, and proportion of time spent performing social and nonsocial behaviors were the dependent variables of interest. No differences in the relative frequency or proportion of time spent performing the target behaviors were observed. However, ethanol consumption significantly decreased bouts of walking, resting, and the duration of trophallactic (i.e., food-exchange) encounters. The results of this study suggest that a low dose of ethanol is sufficient to disrupt both social and nonsocial behaviors in honey bees. In view of these results, future behavioral-genetic investigations of honey bee social behavior are encouraged. DOI 10.2466/PR0.106.3.701-717

It is generally accepted that young worker bees (Apis mellifera L.) are highly attracted to queen mandibular pheromone (QMP). Our results challenge this widely held view. We have found that unless young workers are exposed to QMP early in adult life, they, like foragers, avoid contact with this pheromone. Our data indicate that responses to QMP are regulated peripherally, at the level of the antennal sensory neurons, and that a window of opportunity exists in which QMP can alter a young bee's response to this critically important pheromone. Exposing young bees to QMP from the time of adult emergence reduces expression in the antennae of the D1-like dopamine receptor gene, Amdop1. Levels of Amdop3 transcript, on the other hand, and of the octopamine receptor gene Amoa1, are significantly higher in the antennae of bees strongly attracted to QMP than in bees showing no attraction to this pheromone. A decline in QMP attraction with age is accompanied by a fall in expression in worker antennae of the D2-like dopamine receptor, AmDOP3, a receptor that is selectively activated by QMP. Taken together, our findings suggest that QMP's actions peripherally not only suppress avoidance behavior, but also enhance attraction to QMP, thereby facilitating attendance of the queen. dopamine | honeybee | olfaction | pheromone doi/10.1073/pnas.0907563106

A prominent theory states that animal phenotypes arise by evolutionary changes in gene regulation, but the extent to which this theory holds true for behavioral evolution is not known. Because 'nature and nurture' are now understood to involve hereditary and environmental influences on gene expression, we studied whether environmental influences on a behavioral phenotype, i.e., aggression, could have evolved into inherited differences via changes in gene expression. Here, with microarray analysis of honey bees, we show that aggression-related genes with inherited patterns of brain expression are also environmentally regulated. There were expression differences in the brain for hundreds of genes between the highly aggressive Africanized honey bee compared with European honey bee (EHB) subspecies. Similar results were obtained for EHB in response to exposure to alarm pheromone (which provokes aggression) and when comparing old and young bees (aggressive tendencies increase with age). There was significant overlap of the gene lists generated from these three microarray experiments. Moreover, there was statistical enrichment of several of the same cis regulatory motifs in promoters of genes on all three gene lists. Aggression shows a remarkably robust brain molecular signature regardless of whether it occurs because of inherited, age-related, or environmental (social) factors. It appears that one element in the evolution of different degrees of aggressive behavior in honey bees involved changes in regulation of genes that mediate the response to alarm pheromone.

Hierarchical population structure, where individuals are aggregated into colonies or similar groups that themselves grow, survive or perish, and potentially produce offspring groups, is an important feature of many biological systems, most notably eusocial organisms such as the honey bee, Apis mellifera. Despite this hierarchical structure, there is a paucity of analytical models and theory linking the dynamics of individuals within colonies to the dynamics of a population of colonies. We present an analytical framework that provides a simple, robust, and predictive theory for the population dynamics of hierarchical organisms. Our framework explicitly describes and links demographic dynamics for the different levels in the hierarchy (individuals, groups, population). We illustrate the application of the framework by developing a model for honey bees and analyzing the effects of life history traits such as worker life span and size at swarming on the growth rate of populations. We conclude by discussing possible extensions of the model that increase its realism and expand its usefulness beyond swarm-founding, monogynous, eusocial insects. Key words: Apis mellifera; bees; demography; eusocial insects; hierarchical population; multilevel selection population model.

By using a functional genomics approach, we have identified a honey bee [Apis mellifera (Am)] odorant receptor (Or) for the queen substance 9-oxo-2-decenoic acid (9-ODA). Honey bees live in large eusocial colonies in which a single queen is responsible for reproduction, several thousand sterile female worker bees complete a myriad of tasks to maintain the colony, and several hundred male drones exist only to mate. The 'queen substance' [also termed the queen retinue pheromone (QRP)] is an eight-component pheromone that maintains the queen's dominance in the colony. The main component, 9-ODA, acts as a releaser pheromone by attracting workers to the queen and as a primer pheromone by physiologically inhibiting worker ovary development; it also acts as a sex pheromone, attracting drones during mating flights. However, the extent to which social and sexual chemical messages are shared remains unresolved. By using a custom chemosensory-specific microarray and qPCR, we identified four candidate sex pheromone Ors (AmOr10, -11, -18, and -170) from the honey bee genome based on their biased expression in drone antennae. We assayed the pheromone responsiveness of these receptors by using Xenopus oocytes and electrophysiology. AmOr11 responded specifically to 9-ODA (EC50 = 280 [+ or -] 31 nM) and not to any of the other seven QRP components, other social pheromones, or floral odors. We did not observe any responses of the other three Ors to any of the eight QRP pheromone components, suggesting 9-ODA is the only QRP component that also acts as a long-distance sex pheromone. queen pheromone | olfaction | functional genomics

Honey bees (Apis mellifera) are regularly faced with the task of navigating back to their hives from remote food sources. They have evolved several methods to do this, including compass-directed 'vector' flights and the use of landmarks. If these hive-centered mechanisms are disrupted, bees revert to searching for the hive, but the nature and efficiency of their searching strategy have hitherto been unknown. We used harmonic radar to record the flight paths of honey bees that were searching for their hives. Our subsequent analysis of these paths revealed that they can be represented by a series of straight line segments that have a scale-free, Levy distribution with an inverse-square-law tail. We show that these results, combined with the 'no preferred direction' characteristic of the segments, demonstrate that the bees were flying an optimal search pattern. Levy movements have already been identified in a number of other animals. Our results are the best reported example where the movements are mostly attributable to the adoption of an optimal, scale-free searching strategy. Key words: flight pattern; harmonic radar; honey bees; Levy flights; optimal searching strategy; scale

Colony defense by honey bees, Apis mellifera, is associated with stinging and mass attack, fueled by the release of alarm phero mones. Thus, alarm pheromones are critically important to surviva of honey bee colonies, Here we report that in the parasitic relationship between the European honey bee and the small hive beetle, Aethina tumida, the honey bee's alarm pheromones serve a negative function because they are potent attractants for the beetle. Furthermore, we discovered that the beetles from both Africa and the United States vector a strain of Kodamaea ohmer yeast, which produces these same honey bee alarm pheromones when grown on pollen in hives. The beetle is not a pest of African honey bees because African bees have evolved effective methods to mitigate beetle infestation. However, European honey bees faced with disease and pest management stresses different from those experienced by African bees, are unable to effectively inhibit beetle infestation. Therefore, the environment of the European honey bee colony provides optimal conditions to promote the unique bee--beetle--yeast--pollen multitrophic interaction that facilitates effective infestation of hives at the expense of the Euro pean honey bee, alarm pheromone | kairomone | small hive beetle

The study presents a complete analysis of a honeybee genome that confirms the presence of a large number of neuropeptides in the insect and also describes and explains its social behavior, as well as its evolution. The analysis states that in spite of the genes being a messenger of the brain's signals and being able to modulate behavior tremendously, its increasing number is not found to be related to the social behavior.

Ancestral developmental programs are used to derive the origins of complex social behavior, from which insect societies emerge. Behavioral assays, selective breeding, and genetic mapping are used to describe the evolution of complex social behavior from heterochronic changes in reproductive signaling systems that govern ubiquitous and ancient relationships between behavior and ovarian development.

Honey bees communicate the location and desirability of valuable forage sites to their nestmates through an elaborate, symbolic 'dance language.' The dance language is a uniquely complex communication system in invertebrates, and the neural mechanisms that generate dances are largely unknown. Here we show that treatments with controlled doses of the biogenic amine neuromodulator octopamine selectively increased the reporting of resource value in dances by forager bees. Oral and topical octopamine treatments modulated aspects of dances related to resource profitability in a dose-dependent manner. Dances for pollen and sucrose responded similarly to octopamine treatment, and these effects were eliminated by treatment with the octopamine antagonist mianserin. We propose that octopamine modulates the representation of floral rewards in dances by changing the processing of reward in the honey bee brain. Octopamine is known to modulate appetitive behavior in a range of solitary insects; the role of octopamine in dance provides an example of how neural substrates can be adapted for new behavioral innovations in the process of social evolution. Apis mellifera | biogenic amine | foraging | reward | social behavior

A study of hygienic behavior of honey bees, Apis mellifera, in mixed colonies during removal of diseased brood to prevent disease transmission with relation to division of labor is presented.

Prompted by doubts about the adequacy of the various control procedures long used in research on blocking, we repeated some earlier experiments with honeybees that had given the appearance of forward, concurrent, and backward blocking. The new experiments differed from the earlier experiments only in that the target stimulus was omitted during the training and was encountered for the first time in the test. In the new experiments, just as in the earlier experiments, the blocking groups responded less to the target stimulus than did the control groups. The results show that the effects of the different treatments of nontarget stimuli commonly compared in blocking experiments may generalize to the target stimulus and thus affect responding to that stimulus independently of experience with it. Implications for research on blocking in honeybees and other animals are considered.

Most insects are thought to fly by creating a leading-edge vortex that remains attached to the wing as it translates through a stroke. In the species examined so far, stroke amplitude is large, and most of the aerodynamic force is produced halfway through a stroke when translation velocities are highest. Here we demonstrate that honeybees use an alternative strategy, hovering with relatively low stroke amplitude ([approximately equal to] 90 [degrees]) and high wingbeat frequency ([approximately equal to] 230 Hz). When measured on a dynamically scaled robot, the kinematics of honeybee wings generate prominent force peaks during the beginning, middle, and end of each stroke, indicating the importance of additional unsteady mechanisms at stroke reversal. When challenged to fly in low-density heliox, bees responded by maintaining nearly constant wingbeat frequency while increasing stroke amplitude by nearly 50%. We examined the aerodynamic consequences of this change in wing motion by using artificial kinematic patterns in which amplitude was systematically increased in 5[degrees] increments. To separate the aerodynamic effects of stroke velocity from those due to amplitude, we performed this analysis under both constant frequency and constant velocity conditions. The results indicate that unsteady forces during stroke reversal make a large contribution to net upward force during hovering but play a diminished role as the animal increases stroke amplitude and flight power. We suggest that the peculiar kinematics of bees may reflect either a specialization for increasing load capacity or a physiological limitation of their flight muscles. bee flight | flight in heliox | stroke amplitude | unsteady mechanisms | wingbeat kinematics

A model was developed that stimulates the movement of swarms and scouts and showed that when scouts fly through swarm at a speed slightly higher than the speed of the other uninformed bees, they are indeed able to direct the swarm toward its new home. The results showed that a small number of informed scouts guided the uninformed bees successfully towards the new home.

The robustness and plasticity of working memory were investigated in honey bees by using a delayed matching-to-sample (DMTS) paradigm. The findings are summarized as follows: first, performance in the DMTS task decreases as the duration between the presentation of the sample stimulus and the presentation of the comparison stimuli is increased. This decrease is well approximated by an exponential decay function. Performance is significantly better than random-choice level even at delays as long as 5 sec and is reduced to random-choice levels at an average delay time of 8.68 [+ or -] 0.06 sec. Second, when the DMTS task involves two samples (one relevant, the other irrelevant), bees can be trained to learn to use the relevant sample to perform the task if (i) the relevant sample is always at a fixed position, or (ii) the relevant sample always has the same place in the sequence of presentation (always first or always second). Bees that have learned to use the relevant sample and to ignore the irrelevant sample can generalize this learning, and apply it to novel sets of sample and comparison stimuli that they have never previously encountered. The findings point to a remarkably robust, and yet plastic, working memory in the honey bee. honey bee learning | matching to sample | maze | tunnel