Proteome Changes Paralleling the Olfactory Conditioning in the Forager Honey Bee and Provision of a Brain Proteomics Dataset

The olfactory conditioning of the bee proboscis extension reflex (PER) is extensively used as a paradigm in associative learning of invertebrates but with limited molecular investigations. To investigate which protein changes are linked to olfactory conditioning, a non‐sophisticated conditioning model is applied using the PER in the honeybee (Apis mellifera). Foraging honeybees are assigned into three groups based on the reflex behavior and training: conditioned using 2‐octanone (PER‐conditioned), and sucrose and water controls. Thereafter, the brain synaptosomal proteins are isolated and analyzed by quantitative proteomics using stable isotope labeling (TMT). Additionally, the complex proteome dataset of the bee brain is generated with a total number of 5411 protein groups, including key players in neurotransmitter signaling. The most significant categories affected during olfactory conditioning are associated with “SNARE interactions in vesicular transport” (BET1 and VAMP7), ABC transporters, and fatty acid degradation pathways.     

Larval Exposure to Parasitic Varroa destructor Mites Triggers Specific Immune Responses in Different Honey Bee Castes and Species

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Non-Specific dsRNA-Mediated Antiviral Response in the Honey Bee

Honey bees are essential pollinators of numerous agricultural crops. Since 2006, honey bee populations have suffered considerable annual losses that are partially attributed to Colony Collapse Disorder (CCD). CCD is an unexplained phenomenon that correlates with elevated incidence of pathogens, including RNA viruses. Honey bees are eusocial insects that live in colonies of genetically related individuals that work in concert to gather and store nutrients. Their social organization provides numerous benefits, but also facilitates pathogen transmission between individuals. To investigate honey bee antiviral defense mechanisms, we developed an RNA virus infection model and discovered that administration of dsRNA, regardless of sequence, reduced virus infection. Our results suggest that dsRNA, a viral pathogen associated molecular pattern (PAMP), triggers an antiviral response that controls virus infection in honey bees.     

Direct Visual Observation of Wing Movements during the Honey Bee Waggle Dance

Recruitment-related behaviours such as waggle dances enable honey bee foragers to inform their nestmates about the location of important resources. However, it is still not known how the information contained in a dance performed in the darkness of the nest is transferred to followers. Although, there are findings indicating that dancing honey bees produce airborne sounds which may convey the information, there has only been indirect evidence that moving wings are the source of these airborne sounds. In this study, honey bee dances were recorded using a high-speed camera in order to directly observe and precisely measure the frequency of wing beats and abdomen wags of dancers. Dancing bees moved their wings for 40.4% of the duration of a waggle run and for only 8.1% of the duration of a circle run. The episodes of wing movements consisted of one to five wing beats and were separated by intervals of motionless wings. The mean frequency of wing beats was 167.0 Hz and significantly differed depending on the number of wing beats in one episode (p < 0.001) and the position of the wings (p = 0.007). The mean frequency of abdomen wags was 14.6 Hz. The mean number of followers was 7.9 and significantly more of them gathered around the abdomens of dancers than around their heads and thoraxes (p = 0.001). The results of this study support the assumption that moving wings are the source of airborne sounds emitted during honey bee dances.     

Colony and Individual Forager Responses to Food Quality in the New World Bumble Bee, Bombus occidentalis

The ability of a successful forager to activate colony foraging allows colonies to rapidly exploit ephemeral resources and is an important innovation in the evolution of sociality. We tested the ability of the species, Bombus occidentalis, to stimulate colony foraging for food varying in quality. We then analyzed the behavior of successful foragers inside the nest to learn more about potential foraging activation movements. The number of bees entering a foraging arena was positively correlated with food sucrose concentration (0.5, 1.0, and 2.5 M sucrose, equal to 16–65% w/w). Foragers spent significantly more time imbibing higher concentration solutions. Foragers then returned to the nest where they moved in elaborate paths at variable speeds. There was no significant effect of sucrose concentration on average forager velocity or time spent inside the nest. However, the length of a forager’s path inside the nest (total of all distances moved each 0.1 s) significantly increased with sucrose concentration. On average, individuals foraging on 2.5 M and 1.0 M solution walked paths respectively 1.6 fold and 1.4 longer than the paths of individuals foraging on 0.5 M solution. These longer paths could result in a greater number of nestmate contacts, a factor shown to be important in the activation of B. impatiens foragers and also reported in B. terrestris foragers.     

In vivo Responses of Honey Bee Midgut Proteases to Two Protease Inhibitors from Potato

Potato protease inhibitors, POT-1 and POT-2, were fed to newly emerged adult honey bees in cages at different doses in either sugar syrup (0.2 or 0.01% w:v) or pollen food (1 or 0.2% w:w). In vivo activities of three digestive endopeptidases (trypsin, chymotrypsin and elastase) and one exopeptidase (leucine aminopeptidase; LAP) were measured after 3 or 8days' exposure of bees to inhibitor. Enzyme activities were significantly lower at day 8 than at day 3, except for elastase, which did not change. POT-2 significantly reduced the activity of all endopeptidases at both timepoints, regardless of the dose level or the medium in which the inhibitor was administered. POT-1 acted in a similar manner, except that 0.01% POT-1 in syrup had no effect on bees. There was no consistent trend in changes in LAP activity. Bees fed either inhibitor at 1% in pollen or at 0.2% in syrup had significantly reduced lifespans, with the effect of the pollen treatment being greater than the syrup treatment. The survival of bees fed POT-1 or POT-2 at 0.2% in pollen or 0.01% in syrup did not differ from the controls.     

Landscape Learning during Flight Ensures Homing in Honey Bee (Apis mellifera) Drones

Journal of Insect Behavior - The role of learning to navigate toward a specific location has been extensively studied in the foraging context of social hymenopteran females, which bring resources...     

秦巴山区蜜蜂资源调查研究

介绍了发生于秦巴山区的蜜蜂物种 5 0种 ,隶属蜜蜂总科之 6科 19属 ;同时介绍了这些物种的发生区域 ,发生期和发生概况。现行研究结果对于揭示、保护、利用当地的蜜蜂资源具有积极的指导作用。     

Brood Pheromone Modulation of Pollen Forager Turnaround Time in the Honey Bee (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.)

Foraging for pollen is an important behavior of the honey bee because pollen is their sole source of protein. Through nurse bees, larvae are the principal consumers of pollen. Fatty acid esters extractable from the surface of larvae, called brood pheromone, release multiple colony-level and individual foraging behaviors increasing pollen intake. In this study pollen forager turnaround time was measured in observation hives supplemented with brood pheromone versus a blank control treatment. Treatment with brood pheromone significantly decreased pollen forager turnaround time in the hive between foraging bouts by approximately 72%. Concurrently, brood pheromone increased the ratio of pollen to non-pollen foragers entering colonies. Brood pheromone has been shown to release most of the mechanisms known to increase pollen intake by colonies acting as an important regulator of colony foraging decisions and growth.     

Gregarines Found in the Honey Bee Apis mellifera Linnaeus in Venezuela.

SUMMARY. Gregarines were found for the first time in the honey bee Apis mellifera L. in Venezuela. The parasites attacked the inner wall of the ventriculus of the adult bees, causing heavy losses in apiculture in October 1954 and June 1955. The disease produced was called gregarina disease of the honey bee (in Spanish "gregarinosis de la abeja").     

Orchid Mimics Honey Bee Alarm Pheromone in Order to Attract Hornets for Pollination

Approximately one-third of the world's estimated 30,000 orchid species are deceptive and do not reward their pollinators with nectar or pollen [1]. Most of these deceptive orchids imitate the scent of rewarding flowers or potential mates [2] and [3]. In this study, we investigated the floral scent involved in pollinator attraction to the rewardless orchid Dendrobium sinense, a species endemic to the Chinese island Hainan that is pollinated by the hornet Vespa bicolor. Via chemical analyses and electrophysiological methods, we demonstrate that the flowers of D. sinense produce (Z)-11-eicosen-1-ol and that the pollinator can smell this compound. This is a major compound in the alarm pheromones of both Asian (Apis cerana) and European (Apis mellifera) honey bees [4] and [5] and is also exploited by the European beewolf (Philanthus triangulum) to locate its prey [6]. This is the first time that (Z)-11-eicosen-1-ol has been identified as a floral volatile. In behavioral experiments, we demonstrate that the floral scent of D. sinense and synthetic (Z)-11-eicosen-1-ol are both attractive to hornets. Because hornets frequently capture honey bees to feed to their larvae, we suggest that the flowers of D. sinense mimic the alarm pheromone of honey bees in order to attract prey-hunting hornets for pollination.     

Using DNA Metabarcoding to Identify the Floral Composition of Honey: A New Tool for Investigating Honey Bee Foraging Preferences

Identifying the floral composition of honey provides a method for investigating the plants that honey bees visit. We compared melissopalynology, where pollen grains retrieved from honey are identified morphologically, with a DNA metabarcoding approach using the rbcL DNA barcode marker and 454-pyrosequencing. We compared nine honeys supplied by beekeepers in the UK. DNA metabarcoding and melissopalynology were able to detect the most abundant floral components of honey. There was 92% correspondence for the plant taxa that had an abundance of over 20%. However, the level of similarity when all taxa were compared was lower, ranging from 22–45%, and there was little correspondence between the relative abundance of taxa found using the two techniques. DNA metabarcoding provided much greater repeatability, with a 64% taxa match compared to 28% with melissopalynology. DNA metabarcoding has the advantage over melissopalynology in that it does not require a high level of taxonomic expertise, a greater sample size can be screened and it provides greater resolution for some plant families. However, it does not provide a quantitative approach and pollen present in low levels are less likely to be detected. We investigated the plants that were frequently used by honey bees by examining the results obtained from both techniques. Plants with a broad taxonomic range were detected, covering 46 families and 25 orders, but a relatively small number of plants were consistently seen across multiple honey samples. Frequently found herbaceous species were Rubus fruticosus, Filipendula ulmaria, Taraxacum officinale, Trifolium spp., Brassica spp. and the non-native, invasive, Impatiens glandulifera. Tree pollen was frequently seen belonging to Castanea sativa, Crataegus monogyna and species of Malus, Salix and Quercus. We conclude that although honey bees are considered to be supergeneralists in their foraging choices, there are certain key species or plant groups that are particularly important in the honey bees environment. The reasons for this require further investigation in order to better understand honey bee nutritional requirements. DNA metabarcoding can be easily and widely used to investigate floral visitation in honey bees and can be adapted for use with other insects. It provides a starting point for investigating how we can better provide for the insects that we rely upon for pollination.     

The Role of the Vibration Signal during Nest‐Site Selection by Honey Bee Swarms

The vibration signal may influence nest‐site selection by honey bee swarms by enhancing scouting and recruitment. We investigated this hypothesis by comparing (1) the number of nest sites and the distances communicated by nest‐site dancers on swarms from which vibrators were and were not removed and (2) the behavior of scouts visiting higher‐quality (HQ) and lower‐quality (LQ) nest boxes. The removal of vibrators from swarms did not alter the number of nest sites investigated, the distances traveled to nest sites, or the time required to select a new nest cavity. In contrast, vibrator removal tripled the time required for swarms to achieve liftoff after a cavity had been selected, although all swarm eventually became airborne and moved to a new site. About 14% of the scouts that visited the HQ and LQ nest boxes performed vibration signals; however, nest‐box quality did not influence the tendency to produce the signal or intermix vibration signals and recruitment dances. However, we did find a significant, positive correlation between overall levels of vibration signal activity and nest‐site recruitment during the house‐hunting process. When viewed in concert, our results suggest that the vibration signal contributes to the house‐hunting process by operating in a non‐specific manner that may enhance scouting and recruitment in general during nest‐site selection and facilitate rapid swarm liftoff after a new nest site has been chosen. The vibration signal is therefore a component in the cascade of communication signals that orchestrate house‐hunting and colony relocation decisions.     

The Shaking Signal of the Honey Bee Informs Workers to Prepare for Greater Activity

One of the most conspicuous activities of worker bees inside a hive is the shaking of other workers. This shaking has long been suspected to be a communication behavior, but its information content and function have until recently remained mysterious. Prior studies of the colony-level patterns of the production of the shaking signal suggest strongly that this signal serves to arouse workers to greater activity, such as at times of good foraging. Data from our observations of individual bees bolster the hypothesis that the shaking signal informs workers to prepare for a higher level of activity. We followed foragers in a colony whose only source of ‘nectar’ was a sugar-water feeder and discovered that when the feeder was left empty for 1–3 d and then refilled, the first bees to find the food initially produced only shaking signals upon return to the hive. It was not until they had completed several trips to the feeder that they began to produce waggle dances. Evidently, the shaking signal and the waggle dance function together to stimulate a colony's foragers to activity.     

Modeling the Adaptive Role of Negative Signaling in Honey Bee Intraspecific Competition

Collective decision making in the social insects often proceeds via feedback cycles based on positive signaling. Negative signals have, however, been found in a few contexts in which costs exist for paying attention to no longer useful information. Here we incorporate new research on the specificity and context of the negative stop signal into an agent based model of honey bee foraging to explore the adaptive basis of negative signaling in the dance language. Our work suggests that the stop signal, by acting as a counterbalance to the waggle dance, allows colonies to rapidly shut down attacks on other colonies. This could be a key adaptation, as the costs of attacking a colony strong enough to defend itself are significant.     

A Game Theoretical Analysis of the Mating Sign Behavior in the Honey Bee

Queens of the honey bee, Apis mellifera (L.), exhibit extreme polyandry, mating with up to 45 different males (drones). This increases the genetic diversity of their colonies, and consequently their fitness. After copulation, drones leave a mating sign in the genital opening of the queen which has been shown to promote additional mating of the queen. On one hand, this signing behavior is beneficial for the drone because it increases the genetic diversity of the resulting colony that is to perpetuate his genes. On the other hand, it decreases the proportion of the drone??s personal offspring among colony members which is reducing drone fitness. We analyze the adaptiveness and evolutionary stability of this drone??s behavior with a game-theoretical model. We find that theoretically both the strategy of leaving a mating sign and the strategy of not leaving a mating sign can be evolutionary stable, depending on natural parameters. However, the signing strategy is not favored for most scenarios, including the cases that are biologically plausible in reference to empirical data. We conclude that leaving a sign is not in the interest of the drone unless it serves biological functions other than increasing subsequent queen mating chances. Nevertheless, our analysis can also explain the prevalence of such a behavior of honey bee drones by a very low evolutionary pressure for an invasion of the nonsigning strategy.