Rainbow bee-eaters (Merops ornatus) as a monitoring tool for honeybees (Apis mellifera L.; Hymenoptera: Apidae)

Abstract Regurgitated pellets were collected from underneath roosts of rainbow bee-eaters in suburban Darwin, Australia, and examined for the presence of wings of honeybees. The proportion of pellets containing wings was compared prior to and after placement or removal of honeybee hives in the vicinity of four roosts. On each occasion, the addition or removal of hives was reflected in proportions of pellets containing wings. The results suggest that examination of pellets beneath bee-eater roosts would be a useful technique for monitoring the occurrence of feral honeybees. Potential uses for this technique in eradication of unwanted bees are discussed.     

Native Prey and Invasive Predator Patterns of Foraging Activity: The Case of the Yellow-Legged Hornet Predation at European Honeybee Hives

Contrary to native predators, which have co-evolved with their prey, alien predators often benefit from native prey naïveté. Vespa velutina, a honeybee predator originating from Eastern China, was introduced into France just before 2004. The present study, based on video recordings of two beehives at an early stage of the invasion process, intends to analyse the alien hornet hunting behaviour on the native prey, Apis mellifera, and to understand the interaction between the activity of the predator and the prey during the day and the season. Chasing hornets spent most of their time hovering facing the hive, to catch flying honeybees returning to the hive. The predation pressure increased during the season confirming previous study based on predator trapping. The number of honeybee captures showed a maximum peak for an intermediate number of V. velutina, unrelated to honeybee activity, suggesting the occurrence of competition between hornets. The number of honeybees caught increased during midday hours while the number of hornets did not vary, suggesting an increase in their efficacy. These results suggest that the impact of V. velutina on honeybees is limited by its own biology and behaviour and did not match the pattern of activity of its prey. Also, it could have been advantageous during the invasion, limiting resource depletion and thus favouring colonisation. This lack of synchronization may also be beneficial for honeybee colonies by giving them an opportunity to increase their activity when the hornets are less effective.     

引入西方蜜蜂对中蜂的危害及生态影响

作者阐述自1896年中国引进西方蜜蜂Apis melliferaL.的优良品种如意大利蜂Apis mellifera ligusticaSpinola和喀尼阿兰蜂Apis mellifera Carnica Pollmann以来,使当地的东方蜜蜂Apis cerana F.受到严重危害,其分布区域缩小75%以上,种群数量减少80%以上。使山林植物授粉总量减少,导致植物多样性减少。文中提出: 建立自然保护区保存本地蜜蜂遗传特性,和采用基因转移等技术,培育具有西方蜜蜂优良生产性能的中蜂新品种,逐步恢复中蜂的种群数量。     

蜜蜂体内王浆主蛋白基因mrjp9的转录表达研究

蜜蜂体内有9种王浆蛋白基因(major royal jelly protein,MRJPs1～9),其中MRJPs1～5在蜂王浆中含量较高,是蜂王浆生物学功能的基础。MRJPs6～9在王浆中没有或含量极少,且功能未知。为研究非王浆蛋白组分的MRJP9的生物学功能,本研究用RT-PCR的方法对意大利蜜蜂Apis mellifera ligustica Spinola不同组织,不同部位,不同级型样本中mrjp9的转录水平进行检测和定量。结果发现mrjp9在蜜蜂的幼虫、蛹和成年蜜蜂的各组织部位均广泛转录表达,但其在幼虫、蛹和刚出房的成年蜜蜂体内表达水平较低,而在成年采集蜂体内表达水平则较高,其表达与蜜蜂的发育时期有关。通过对在成年蜜蜂体内各组织部位的表达水平进行检测的结果显示该基因主要在蜜蜂的头、胸和王浆腺等组织部位的表达较高,其他组织部位表达较少。此外,该基因也在雄蜂和蜂王体内广泛表达,不受蜜蜂性别和级型的影响。这些结果说明mrjp9是一与蜜蜂发育有关的基因,可能与蜜蜂的行为发育和分工调控有关。     

云南食用蜜蜂种类调查及鉴定

在云南,人们有食用蜜蜂幼虫和蛹的习俗。市场上销售的蜜蜂幼虫和蛹多经热水烫过或煮过,因而缺少成虫形态,俗名易混用,食用种类长期未予明确。本文在市场调查的基础上,收集其中部分样品,通过形态学和mtDNA的COI基因部分序列初步鉴定其分类地位,以明确食用种类。结果表明,云南蜜蜂的食用集中在横断山脉南部地区,接受人群广泛,食用方式多样;云南食用本地分布的全部5种野生蜜蜂,包括东方蜜蜂(Apis cerana)、小蜜蜂(A.florea)、大蜜蜂(A.dorsata)、黑大蜜蜂(A.laboriosa)和黑小蜜蜂(A.andreniformis);基于COI序列构建的邻接法(NJ)和最大简约法(MP)系统发育树支持现有的蜜蜂属系统发育关系;现有的食用蜜蜂大多采集自野外,亟待开展遗传资源保护。本研究为食用蜜蜂的鉴定提供了数据支持,也为蜜蜂自然资源的利用和保护提供参考。     

蜜蜂嗅觉相关蛋白的研究进展

蜜蜂是一类营社会性生活的昆虫,蜂群中的蜂王、工蜂和雄蜂相互依存,各司其职,共同维持着群体严密有序的生活。其中,嗅觉系统在它们的生存和繁衍过程中起到重要的作用。昆虫对气味物质的感受过程是非常复杂的,需要有多种蛋白的参与。研究蜜蜂的化学感受机制可以帮助我们更深入地了解蜜蜂特有的行为及生物学特性。本文重点综述了与蜜蜂嗅觉相关的3种蛋白质的生化特性、分子结构、基因表达及其生理功能等方面的研究进展,以期为今后开展相关研究工作提供理论参考。     

Ultrastructural analysis on the gland secretion in the extracellular ducts of the hypopharyngeal glands of the honeybee infected by Nosema apis

The hypopharyngeal glands of the honeybee secrete the larval food royal jelly, along with enzymes that are used in the production of honey from nectar. The composition of this secretion mixture varies with the physiological condition of the honeybee, and the final secretion mixture is conveyed through the extracellular ducts to the large excretory duct. The secretion products in the extracellular duct of both healthy and infected honeybees, was studied by transmission electron microscopy and image analysis. These products consisted of a densely packed, faintly visible granular substance. The granules were clearly defined by the computer enhanced image. The secretion products from the Nosema-infected honeybees exhibited the same granular structure, but were much less concentrated, thereby reducing the overall electron density of the secretion. These observations suggest that the composition of the secretion products from the hypopharyngeal glands in the Nosema-infected honeybees, was altered considerably.     

Farming with native bees (<Emphasis Type="Italic">Apis mellifera</Emphasis> subsp. <Emphasis Type="Italic">capensis</Emphasis> Esch.) has varied effects on nectar-feeding bird communities in South African fynbos vegetation

Outside their natural range, honeybees (Apis mellifera) are known to have detrimental effects on indigenous pollinators through exploitative or interference competition, but little is known about the effect of honeybee farming in areas where honeybees occur naturally. In the Cape Floristic Region of South Africa, where honeybees are indigenous, managed hives potentially elevate the abundance of honeybees far above natural levels, but impacts on other floral resource-dependent species have not been studied. Here we use experimental manipulation of honeybee density to test whether honeybee farming affects nectar-feeding birds. We selected the common sugarbush (Protea repens), utilized by both birds and bees, and analysed the time (before/after) by treatment (control/experiment) interaction to explore changes in bee abundance, nectar availability and bird abundance at three sites. Hive addition increased honeybee abundance in inflorescences of P. repens above expected levels. Despite experimental increase in honeybee numbers, there is no reduction in nectar sugar availability relative to the control areas. Where honeybee density was highest, sugarbird (Promerops cafer) numbers declined relative to expected, but sunbirds (Nectarinidae) were not affected at any of the sites. We conclude that stocking rates of more than one honey bee per P. repens inflorescence have detrimental effects on bird abundance due to interference, rather than resource competition.     

Pyrethroids and Nectar Toxins Have Subtle Effects on the Motor Function,Grooming and Wing Fanning Behaviour of Honeybees (Apis mellifera)

Sodium channels, found ubiquitously in animal muscle cells and neurons, are one of the main target sites of many naturally-occurring, insecticidal plant compounds and agricultural pesticides. Pyrethroids, derived from compounds found only in the Asteraceae, are particularly toxic to insects and have been successfully used as pesticides including on flowering crops that are visited by pollinators. Pyrethrins, from which they were derived, occur naturally in the nectar of some flowering plant species. We know relatively little about how such compounds—i.e., compounds that target sodium channels—influence pollinators at low or sub-lethal doses. Here, we exposed individual adult forager honeybees to several compounds that bind to sodium channels to identify whether these compounds affect motor function. Using an assay previously developed to identify the effect of drugs and toxins on individual bees, we investigated how acute exposure to 10 ng doses (1 ppm) of the pyrethroid insecticides (cyfluthrin, tau-fluvalinate, allethrin and permethrin) and the nectar toxins (aconitine and grayanotoxin I) affected honeybee locomotion, grooming and wing fanning behaviour. Bees exposed to these compounds spent more time upside down and fanning their wings. They also had longer bouts of standing still. Bees exposed to the nectar toxin, aconitine, and the pyrethroid, allethrin, also spent less time grooming their antennae. We also found that the concentration of the nectar toxin, grayanotoxin I (GTX), fed to bees affected the time spent upside down (i.e., failure to perform the righting reflex). Our data show that low doses of pyrethroids and other nectar toxins that target sodium channels mainly influence motor function through their effect on the righting reflex of adult worker honeybees.     

Pattern recognition in honeybees: chromatic properties of orientation analysis

The spectral properties of the discrimination of pattern orientation in freely flying honeybees (Apis mellifera) were examined. Bees were trained to discriminate between two random black/white gratings oriented perpendicularly to each other, one of which was associated with a reward. Subsequently the bees were tested on two-colour gratings or gratings consisting of grey and coloured stripes, providing a range of different chromatic contrasts, luminance contrasts and specific channel contrasts. The results of these experiments indicate that orientation analysis in the honeybee is mediated almost exclusively by the green receptor channel, although the bee's visual system as a whole is endowed with excellent trichromatic colour vision.     

Barbs Facilitate the Helical Penetration of Honeybee (Apis mellifera ligustica) Stingers

The stinger is a very small and efficient device that allows honeybees to perform two main physiological activities: repelling enemies and laying eggs for reproduction. In this study, we explored the specific characteristics of stinger penetration, where we focused on its movements and the effects of it microstructure. The stingers of Italian honeybees (Apis mellifera ligustica) were grouped and fixed onto four types of cubic substrates, before pressing into different substrates. The morphological characteristics of the stinger cross-sections were analyzed before and after penetration by microscopy. Our findings suggest that the honeybee stinger undergoes helical and clockwise rotation during penetration. We also found that the helical penetration of the stinger is associated directly with the spiral distribution of the barbs, thereby confirming that stinger penetration involves an advanced microstructure rather than a simple needle-like apparatus. These results provide new insights into the mechanism of honeybee stinger penetration.     

How do honeybees attract nestmates using waggle dances in dark and noisy hives?

It is well known that honeybees share information related to food sources with nestmates using a dance language that is representative of symbolic communication among non-primates. Some honeybee species engage in visually apparent behavior, walking in a figure-eight pattern inside their dark hives. It has been suggested that sounds play an important role in this dance language, even though a variety of wing vibration sounds are produced by honeybee behaviors in hives. It has been shown that dances emit sounds primarily at about 250-300 Hz, which is in the same frequency range as honeybees' flight sounds. Thus the exact mechanism whereby honeybees attract nestmates using waggle dances in such a dark and noisy hive is as yet unclear. In this study, we used a flight simulator in which honeybees were attached to a torque meter in order to analyze the component of bees' orienting response caused only by sounds, and not by odor or by vibrations sensed by their legs. We showed using single sound localization that honeybees preferred sounds around 265 Hz. Furthermore, according to sound discrimination tests using sounds of the same frequency, honeybees preferred rhythmic sounds. Our results demonstrate that frequency and rhythmic components play a complementary role in localizing dance sounds. Dance sounds were presumably developed to share information in a dark and noisy environment.     

Exogenous and endogenous fluctuations of thermoregulatory activity in the honeybee

Thermovision and thermometric methods were used to study temperature variations in honeybee nests and in aggregations of honeybees isolated from their families. Endogenous and exogenous circadian rhythms of thermoregulatory activity and their physiological mechanisms were revealed. The magnitude of changes in this activity in response to ambient temperature decreased from the beginning to the end of wintering, which was due to the existence of a genetically determined self-regulation program in honeybees. The improvement of this program in the course of the species evolution contributed to transformation of a honeybee family into a reproducible biological unit.     

多巴胺神经通路及其对蜜蜂行为的影响

蜜蜂复杂的社会行为受到了研究者的广泛关注,了解蜜蜂的学习、记忆、导航、信息传递等行为的神经分子基础,可对探索人类自身的脑科学和复杂社会行为的分子基础提供比较研究信息。本文综述了多巴胺的作用机制及其在蜜蜂行为中的作用,详细介绍了蜜蜂脑部的多巴胺受体,总结了蜜蜂脑部多巴胺水平的影响因子等,最后对进一步研究多巴胺神经通路对蜜蜂行为的作用及机制的前景做一展望。     

Wetting Characteristics of Insect Wing Surfaces

Biological tiny structures have been observed on many kinds of surfaces such as lotus leaves,which have an effect on thecoloration of Morpho butterflies and enhance the hydrophobicity of natural surfaces.We investigated the micro-scale andnano-scale structures on the wing surfaces of insects and found that the hierarchical multiple roughness structures help in enhancingthe hydrophobicity.After examining 10 orders and 24 species of flying Pterygotan insects,we found that micro-scaleand nano-scale structures typically exist on both the upper and lower wing surfaces of flying insects.The tiny structures such asdenticle or setae on the insect wings enhance the hydrophobicity,thereby enabling the wings to be cleaned more easily.And thehydrophobic insect wings undergo a transition from Cassie to Wenzel states at pitch/size ratio of about 20.In order to examinethe wetting characteristics on a rough surface,a biomimetic surface with micro-scale pillars is fabricated on a silicon wafer,which exhibits the same behavior as the insect wing,with the Cassie-Wenzel transition occurring consistently around apitch/width value of 20.     

Bacterial community structures in honeybee intestines and their response to two insecticidal proteins

In this study, the effects of the Bt-toxin Cry1Ab and a soybean trypsin inhibitor (SBTI) on intestinal bacterial communities of adult honeybees (Apis mellifera) were investigated. It was hypothesized that changes in intestinal bacterial communities of honeybees may represent a sensitive indicator for altered intestinal physiology. Honeybees were fed in a laboratory set-up with maize pollen from the Bt-transgenic cultivar MON810 or from the non-transgenic near isoline. Purified Cry1Ab (0.0014% w/v) and SBTI (0.1% or 1% w/v) represented supplementary treatments. For comparison, free-flying honeybees from two locations in Switzerland were analysed. PCR-amplification of bacterial 16S rRNA gene fragments and terminal restriction fragment length polymorphism analyses revealed a total of 17 distinct terminal restriction fragments (T-RFs), which were highly consistent between laboratory-reared and free-flying honeybees. The T-RFs were affiliated to Alpha-, Beta-, and Gammaproteobacteria, to Firmicutes, and to Bacteriodetes. Neither Bt-maize pollen nor high concentrations of Cry1Ab significantly affected bacterial communities in honeybee intestines. Only the high concentration of SBTI significantly reduced the number of T-RFs detected in honeybee midguts, a concentration that also increases bee mortality. Therefore, total bacterial community structures may not be a sensitive indicator for providing evidence for the impact of insecticidal proteins on honeybees at sublethal levels.     

Synthetic Nasonov gland pheromone enhances abundance and visitation of honeybee,Apis mellifera,in Korla fragrant pear,Pyrus sinkiangensis

1. Korla fragrant pear (Pyrus sinkiangensis Yü) depends on cross-pollination by honeybees (Apis mellifera) but may suffer from low honeybee visitation.
2. We assessed whether honeybee abundance and visitation frequency are enhanced by using synthetic Nasonov gland pheromone (NGP), which is naturally produced by worker bees to stimulate the aggregation of bees to food resources or nesting sites.
3. The response of honeybees to synthetic NGP was firstly assessed using Y-tube olfactometer tests in the laboratory, and subsequently in the field, by placing NGP lures on Korla fragrant pear trees in orchards with and without beehives. Honeybee abundance was assessed using coloured pan traps while honeybee visits were assessed by visual observations on pear flowers.
4. Y-tube olfactometer tests showed a significant preference of honeybees for NGP. In pear orchards with beehives, honeybee abundance was 2.5-fold higher on trees with NGP lures than on trees without NGP, and 2.2-fold higher in orchards in which all trees contained NGP lures than in orchards without NGP lures. Such positive effects were not observed in orchards without beehives.
5. Flower visitation by honeybees was significantly higher in trees with NGP lures than without NGP lures, irrespective of the presence (5.7-fold higher) or absence of beehives (27.6-fold higher).
6. In mixed pear-apricot orchards, honeybee abundance was higher in pear trees with NGP lures than without lures.
7. Our results show that NGP lures attract honeybees to flowering pear trees in monoculture pear and mixed pear-apricot orchards, and that this effect is greatest in orchards with beehives.

     

Environmental factors have a strong impact on the composition and diversity of the gut bacterial community of Chinese black honeybees

The Chinese black honeybees is an ecotype of the European honeybee that is formed by the natural hybridization of Apis mellifera mellifera and A. m. carnica. It is distributed in nature reserves in North China and has been an important breeding resource for disease resistance and other desirable traits. Compared to the areas outside of reserves, the nature reserves offer significant biodiversity benefits not only to the Chinese black honey bees but also to the other valuable plants and animals. In recent years there has been growing evidence that environmental factors including food choices play an important role in shaping the composition and activity of gut microbiota, which in turn can impact host health. In the previous studies on Chinse black honeybees, little attention has been paid to the diverse population of microbes in the gut that play a vital role in host health. In order to achieve a better understanding on the role of environmental factors in diversity and composition of gut microbiota of honey bees, in the present study, we analyzed the gut bacterial communities of Chinese black honeybees using terminal restriction fragment length polymorphism (T-RFLP). The results showed that the samples from the national nature reserves that are protected and managed so as to preserve and enrich their natural condition and resources for Chinese black honeybees had higher variety and richness of gut bacteria than that collected from unreserved regions that also harbor populations of Chinese black honeybees. The four terminal restriction fragments (T-RFs), 201, 223, 247 and 320 bp, were identified to be the dominant bacteria of Chinese black honeybees. Of which 247 and 320 bp had greater differences between bee groups sampled in different regions and therefore could be used as genetic markers to separate samples collected from the national nature reserves to samples collected from unreserved regions. The results clearly indicate that national nature reserve protects biological diversity and ecological and evolutionary processes which have had a significant influence on the diversity of gut bacteria of Chinese black honeybees. The ubiquity of gut symbiotic bacteria identified in Chinese black honeybee suggests that environmental factors could play an important role in diversity and composition of gut bacteria and warrant further investigation into the functional significance of these gut bacteria for the honeybee health.     

Hygropreference and brood care in the honeybee (Apis mellifera)

Terrestrial organisms need to limit evaporation from their bodies in order to maintain a homeostatic water balance. Owing to a large surface to volume ratio, arthropods are particularly susceptible to desiccation and have evolved behavioural and physiological mechanisms to conserve water. In social insects, water balance is also affected by the interactions between nestmates and by the architecture of the nest. For honeybees, humidity is particularly important for the brood because it affects the hatching success of eggs and because, unlike ants, honeybees cannot relocate their brood to parts of the nest with more favourable humidity. To advance the understanding of the water economy in honeybee nests, we investigated whether workers exhibit a hygropreference when exposed to a gradient of 24-90% relative humidity (RH) and whether the expression of this preference and their behaviour is affected by the presence of brood. The results show that young honeybee workers in the absence of brood exhibit a weak hygropreference for approximately 75% RH. When brood is present the expression of this preference is further weakened, suggesting that workers tend to the brood by distributing evenly in the gradient. In addition, fanning behaviour is shown to be triggered by an increase in humidity above the preferred level but not by a decrease. Our results suggest that humidity in honeybee colonies is actively controlled by workers.     

Detection and Identification of a Novel Lactic Acid Bacterial Flora Within the Honey Stomach of the Honeybee Apis mellifera

This investigation concerned the question of whether honeybees collect bacteria that are beneficial for humans from the flowers that contribute to formation of their honey. Bacteria originating from the types of flowers involved, and found in different anatomic parts of the bees, in larvae, and in honey of different types, were sampled during a 2-year period. 16S rRNA sequencing of isolates and clones was employed. A novel bacterial flora composed of lactic acid bacteria (LAB) of the genera Lactobacillus and Bifidobacterium, which originated in the honey stomach of the honeybee, was discovered. It varied with the sources of nectar and the presence of other bacterial genera within the honeybee and ended up eventually in the honey. It appeared that honeybees and the novel LAB flora may have evolved in mutual dependence on one another. It was suggested that honey be considered a fermented food product because of the LAB involved in honey production. The findings are seen as having clear implications for future research in the area, as providing a better understanding the health of honeybees and of their production and storage of honey, and as having clear relevance for future honeybee and human probiotics.