Nectar and pollen sources for honeybees in Kafrelsheikh province of northern Egypt

This study was conducted at the apiary of the Beekeeping Research Section at the Sakha Agricultural Research Station, ARC, Kafrelsheikh, and other apiaries in Kafrelsheikh province, during two successive years 2015 and 2016. The study aimed to survey nectar and pollen floral resources in Kafrelsheikh province. Ninty seven plant species belonging to 33 families were recorded as nectar sources, and 82 plant species belonging to 36 families were recorded as pollen sources during the whole year. The largest amount of monthly trapped pollen was obtained during May followed by August. It can be concluded that, beekeepers in Kafrelsheikh province can harvest good honey yield at the end of blooming seasons of citrus (Citrus spp.) during March and April, Egyptian clover (Trifolium alexandrinum L.) during May and June, loofah (Luffa aegyptiaca Mill.) during June to October, cotton (Gossypium spp.) during July and August, and banana (Musa spp.) during August and September. They also, could be trapping pollen loads collected from faba bean (Vicia faba L.) and flax (Linum usitatissimum L.) during January to March, date palm (Phoenix dactylifera L.) during March and April, Egyptian clover during May and June, summer seed watermelon (Citrullus lanatus var. colothynthoides L.) during June and July, loofah and maize (Zea mays L.) during June to November.     

蜜蜂人工代用花粉中适宜钙磷水平的初步研究

钙磷是蜜蜂饲粮中必需的常量元素。为了探讨蜜蜂人工代用花粉中适宜的钙磷水平,本试验选取蜂王、群势基本一致的意大利蜜蜂Apis mellifera ligustica Spinola 70群,随机分为14个组,每组5群蜂,前12组饲喂采用均匀设计法配制的不同钙磷水平的人工代用花粉。第13组饲喂不加钙磷的人工代用花粉为负对照,第14组饲喂纯油菜花粉为正对照。试验从春繁开始,到刺槐流蜜期结束为止。试验期间测定蜂群的采食量、蜂群群势、幼蜂初生重,成蜂蜂体组织内钙磷含量。结果表明:当人工代用花粉中钙磷水平分别为0,0.65%时,蜂群的采食量、蜂群群势、幼蜂初生重均取得最大值;成蜂蜂体组织内钙含量与人工代用花粉中钙磷含量成正相关,成蜂蜂体组织内磷含量与人工代用花粉中钙磷含量之间没有相关性。     

Botanical origin and geographic differentiation of bee-pollen produced in high mountains from the Colombian eastern Andes

In the high mountains of the Colombian Eastern Cordillera (~2000–3000 m above sea level), at the Altiplano Cundiboyacense region and surroundings, beekeepers have specialised in pollen production with substantial harvests all year round. Despite this productive advantage, the knowledge about plants used by honeybees as pollen resources is still limited. Hence, the aim of this work was to identify the botanical origin of bee pollen from this region and to examine differences between five distinguished sub-regions: Sabana de Bogotá, Fúquene, Márquez, Tundama and Norte-Gutiérrez. By means of palynological analyses of 86 pollen samples produced between 2008 and 2010, we found a total amount of 126 pollen types, most of them belonging to the families Asteraceae and Fabaceae. Major pollen types correspond to the exotic taxa Hypochaeris radicata, Brassicaceae, Eucalyptus globulus, Trifolium repens, Trifolium pratense and the native taxa Quercus humboldtii and Weinmannia sp. Differences between sample groups from the five sub-regions were mainly associated to variations in pollen abundance and frequency of native plant species. This result highlights the potential for commercialising bee-pollen from the Colombian Eastern Cordillera with geographical origin differentiation, as well as the importance for beekeeping in promoting the conservation of the natural ecosystems from the region.     

Conserving genetic diversity in the honeybee: Comments on Harpur et al. (2012)

The article by Harpur et al. (2012) ‘Management increases genetic diversity of honey bees via admixture’ concludes that ‘…honey bees do not suffer from reduced genetic diversity caused by management and, consequently, that reduced genetic diversity is probably not contributing to declines of managed Apis mellifera populations’. In the light of current honeybee and beekeeping declines and their consequences for honeybee conservation and the pollination services they provide, we would like to express our concern about the conclusions drawn from the results of Harpur et al. (2012). While many honeybee management practices do not imply admixture, we are convinced that the large-scale genetic homogenization of admixed populations could drive the loss of valuable local adaptations. We also point out that the authors did not account for the extensive gene flow that occurs between managed and wild/feral honeybee populations and raise concerns about the data set used. Finally, we caution against underestimating the importance of genetic diversity for honeybee colonies and highlight the importance of promoting the use of endemic honeybee subspecies in apiculture.     

Seasonal variation in vegetation and pollen collected by honeybees in Thessaloniki,Greece

Pollen is important for the nutrition of honeybees and it is necessary for their survival and reproduction. In this study, we collected daily the pollen pellets from four colonies and also recorded the plants in flower in the area around the apiary, over a two‐year period. Field records revealed the presence of 204 species with Asteraceae, Fabaceae and Rosaceae being the most specious families. Although honey bees collected more than 140 pollen types, the main pollen sources (>60% of the total weight) came from less than ten taxa. The most important pollen types with respect to total weight were Sisymbrium irio, Papaver rhoeas, Verbascum sp., Polygonum aviculare, Zea mays and Olea europaea. The use of pollen traps proved a more accurate method to record the type and the foraging period during which the honeybees collect pollen, compared to field observations.     

不同组配的蜜蜂信息素对西方蜜蜂的蜂蜜生产及繁殖性能影响

为了探究不同组配的蜜蜂信息素对西方蜜蜂Apis mellifera蜂蜜生产及繁殖性能的影响。本研究在不同浓度（0.05 μg/μL、0.10 μg/μL和0.15 μg/μL）反式-9-氧代-2-癸烯酸\[(E)-9-oxodec-2-enoicacid,9-ODA\]对工蜂卵黄原蛋白基因（Vg）表达影响基础上,以蜂蜡为载体,用4种蜂王上颚腺信息素（9-ODA,9-HDA,HOB,HVA）与蜜蜂幼虫饥饿信息素（β-罗勒烯）按照一定比例组配了4种蜜蜂信息素挂片（T1-1、T1-2、T2-1、T2-2）,同时以纯蜂蜡挂片作为空白对照组（CK）。系统研究了4种蜜蜂信息素挂片对西方蜜蜂无王群急造王台以及有王群的蜂蜜产量、封盖子数和群势影响。结果表明：人工饲喂0.05 μg/μL、0.10 μg/μL和0.15 μg/μL的9-ODA,对工蜂Vg表达水平具有显著抑制作用（P<0.05）;与对照组相比,4个实验组（T1-1、T1-2、T2-1和T2-2组）出现封盖王台的时间均有显著延迟（P<0.05）,推迟时间2~3 d;T2-1组蜂蜜产量显著高于对照组（P<0.05）,蜂蜜产量提高24.00%;T1-2组、T2-1组和T2-2组封盖子数量都显著高于对照组（P<0.05）,分别提高84.52%、64.50%和80.09%;T1-2组和T2-1组蜂群群势显著高于对照组（P<0.05）,分别提高了53.37%和50.85%。因此不同组配的蜜蜂信息素对西方蜜蜂蜂蜜生产及繁殖性能都起到了积极作用,相关研究结果对养蜂生产中合理利用蜜蜂信息素有指导意义。     

The interplay between dancing and trophallactic behavior in the honey bee Apis mellifera

The interplay between the recruitment dance and food-giving trophallactic contacts of returning Apis mellifera foragers was analyzed. Dancing and trophallactic events were recorded for bees returning from a rate feeder that provided 50% weight on weight sucrose solution at a constant flow rate of 5 μl min⁻¹. Bees that had danced immediately before their trophallactic contact had more recipients per trophallaxis compared with bees that did not dance before. Thus, besides information coded in dancing behavior, dance maneuvers could serve as a stimulus to increase attention of bees located on the dance floor to receive nectar. In addition, the number of bees receiving food during a trophallaxis showed a positive correlation with the probability of dancing immediately after contacting. The time from arrival at the hive to when the first or the subsequent contacts took place presented no correlation with the probability of dancing after trophallaxis. Also, the duration of a trophallaxis was positively correlated with the number of recipients per trophallaxis. These results suggest that returning foragers could receive information during a trophallactic contact with their hive mates that modify thresholds for dancing. Dance maneuvers and trophallactic contacts performed by foraging bees seem to be “mutually” affected. Accepted: 29 November 1999     

Foraging pauses and their meaning as an economic strategy in the honeybee Apis mellifera L.

When conditioned honeybees collect sucrose solution delivered at a range of low-profit flow rates for the hive, they increase the pause length between successive visits. If sucrose solution was delivered continuously, it accumulated at the food source in an amount proportional to the pause length and the flow rate of nectar. When the flow rate of sucrose solution was further decreased but kept constant throughout the day, a threshold level was attained in which oscillations in the length of the pauses were observed. The relationship between the amount of accumulated nectar and subsequent pause length at this threshold level can be depicted by means of a power function. The best fit allowed the calculation of the values of parameters that quantitatively describe the control system regulating foraging activity. The importance of foraging pauses as a strategy to cope with changing nectar availability is discussed. Accepted: 7 January 1998     

Effects of Proteinase Inhibitor Ingestion on Survival,Learning Abilities and Digestive Proteinases of the Honeybee

The impact on beneficial insects of proteinase inhibitors expressed in pest-resistant transgenic crops needs to be assessed before the release of these plants into the environment. Three proteinase inhibitors, suitable for incorporation into oilseed rape, were tested on worker bees: the chicken egg white cystatin, oryzacystatin I (OCI) and Bowman-Birk soyabean inhibitor (BBI). Ingestion of low doses of the inhibitors did not cause short-term mortality, and a conditioned proboscis extension assay showed that olfactory learning performances were unchanged when the inhibitors were added to the reward. Long-term ingestion of BBI or OCI did not disrupt total digestive proteolytic activity, but ingestion of BBI induced a new proteinase form, suggesting the existence of a mechanism of control of proteinase synthesis in the honeybee.     

Flower choice by honey bees (Apis mellifera L.): sex-phase of flowers and preferences among nectar and pollen foragers

Bees foraging for nectar should choose different inflorescences from those foraging for both pollen and nectar, if inflorescences consist of differing proportions of male and female flowers, particularly if the sex phases of the flowers differ in nectar content as well as the occurrence of pollen. This study tested this prediction using worker honey bees (Apis mellifera L.) foraging on inflorescences of Lavandula stoechas. Female flowers contained about twice the volume of nectar of male flowers. As one would predict, bees foraging for nectar only chose inflorescences with disproportionately more female flowers: time spent on the inflorescence was correlated with the number of female flowers, but not with the number of male flowers. Inflorescence size was inversely correlated with the number of female flowers, and could be used as a morphological cue by these bees. Also as predicted, workers foraging for both pollen and nectar chose inflorescences with relatively greater numbers of both male and female flowers: time spent on these inflorescences was correlated with the number of male flowers, but not with the number of females flowers. A morphological cue inversely associated with such inflorescences is the size of the bract display. Choice of flowers within inflorescences was also influenced predictably, but preferences appeared to be based upon corolla size rather than directly on sex phase.     

意大利蜜蜂工蜂唾腺和中肠消化酶活性比较研究

对意大利蜜蜂 Apis mellifera ligustica L工蜂唾腺和中肠中淀粉酶、蛋白酶、蔗糖酶、果胶酶和海藻糖酶5种消化酶进行活性测定,发现巾肠的蛋门酶和蔗糖酶活性较唾腺高,有显著性差异;唾腺的果胶酶活性较中肠高,有显著性差异;唾腺与中肠的淀粉酶和海藻糖酶没有显著性差异.表明意大利蜜蜂工蜂对蔗糖和蛋白的消化主要由中肠分泌的消化酶来完成,唾腺起辅助作用;对果胶的消化主要在唾腺,中肠起辅助作用;而在淀粉和海藻糖的消化过程中唾腺和中肠都有很重要的作用.     

Influence of pollen quality on ovarian development in honeybee workers (Apis mellifera scutellata)

Protein-rich diets are known to promote ovarian and egg development in workers of the honeybee, Apis mellifera, even in the presence of a queen. Since the main source of protein for honeybees is pollen, its quality and digestibility might be important dietary factors determining reproductive capacity. We have compared the effect of two types of pollen-sunflower, Helianthus annuus, and aloe, Aloe greatheadii var davyana-on ovarian development in A. mellifera scutellata workers. Under queenright conditions in the field, worker bees exhibited greater ovarian development when feeding on aloe pollen than on sunflower pollen. In their midgut, we observed higher extraction efficiency for aloe (80%) than for sunflower (69%) pollen. This may be attributed to the morphology and size of the two kinds of pollen grains and explains, together with the high protein content of aloe pollen (32% dry mass in bee-collected pollen) compared to sunflower pollen (15%), why aloe pollen promoted higher ovarian development. However, in the laboratory workers sustained on aloe pollen had significantly less-developed ovaries and higher mortality than those fed sunflower pollen. These detrimental effects may be due to an unbalanced protein:carbohydrate ratio. We discuss the effects of unbalanced diets on the physiology and ecology of honeybee reproduction.     

In vitro haploid formation from pollen: a critical review

Summary In the field of regeneration of plant in vitro cultures, haploid formation from pollen is the scientifically most advanced, but at the same time very controversial system. In the present state of transition from basic research to commercial application, a sound scientific basis of pollen embryogenesis would make this transition much easier. New discoveries in recent years have made it possible to develop a new view of pollen embryogenesis. The new view includes recognition-theoretical aspects, provides a model for a number of problems in plant development, and has consequences for strategies for haploid production. The accumulated knowledge in the field of pollen plant formation is critically analyzed against this new view.     

Daily number of bee louse (Braula coeca) in honey bee (Apis mellifera carnica and A. m. syriaca) colonies maintained under semi‐arid conditions

Experimental work was conducted at two apiaries located in Irbid district and in Shuna North, Jordan, during the years 2004–2006. The aims of these investigations were to estimate the seasonal changes in the infestation rates of the bee louse (Braula sp.) and to develop an easy and rapid method of estimating the infestation rate on workers with bee Braula. Two major honey bee subspecies are reared in Jordan; Apis mellifera carnica and Apis mellifera syriaca were used in this study. The results showed that the infestation rate began to increase rapidly in May, reaching the season's maximum rate of 16.2%, 15.8% and 17.4% for A. m. carnica and 22.6%, 23.9% and 22.9% for A. m. syriaca in December of 2004, 2005 and 2006, respectively. The maximum adult numbers of bees were found in April and June, whereas the minimum for the year was in January in both honey bee subspecies colonies during the study period. The actual population of the bee louse could be estimated by counting the daily dropped lice and multiplying by a factor of 158. This factor is valid for the experimental colonies of both subspecies kept for 3 years under semi‐arid Mediterranean conditions.     

Muscle potentials and temperature acclimation and acclimatization in flight muscles of workers and drones of Apis mellifera

1. 1.Muscle potentials in fibrillar flight muscles of worker and drone honeybees were recorded extracellularly at thoracic temperatures from 30 to 10°C.

2. 2.Extinction temperatures for muscle potentials were higher in drones for all treatments.

3. 3.Cold acclimation (15°C) lowered extinction temperatures significantly in workers and drones. Acclimitization changed extinction temperatures significantly only in drones.

4. 4.Cold acclimitization had a bigger effect on the rate of muscle potential amplitude decline with decreasing temperature than acclimation.

5. 5.Acclimation and acclimitization had no effect on the increase of muscle potential duration with falling temperature.

6. 6.Muscle potential frequency during shivering was not much different between cold and warm treated bees.

What the honeybee sees: a review of the recognition system of Apis mellifera

Abstract. For many years, two opposing theories have dominated our ideas of what honeybees see. The earliest proposal based on training experiments was that bees detected only simple attributes or features, irrespective of the actual pattern. The features demonstrated experimentally before 1940 were the disruption of the pattern (related to spatial frequency), the area of black or colour, the length of edge, and the angle of orientation of a bar or grating. Cues discovered recently are the range, and radial and tangential edges, and symmetry, relative to the fixation point, which is usually the reward hole. This theory could not explain why recognition failed when the pattern was moved. In the second theory, proposed in 1969, the bee detected the retinotopic directions of black or coloured areas, and estimated the areas of overlap and nonoverlap on each test pattern with the corresponding positions in the training pattern. This proposal explained the progressive loss of recognition as a test pattern was moved or reduced in size, but required that the bees saw and remembered the layout of every learned pattern and calculated the mismatch with each test image. Even so, the same measure of the mismatch was given by many test patterns and could not detect a pattern uniquely. Moreover, this theory could not explain the abundant evidence of simple feature detectors. Recent work has shown that bees learn one or more of a limited number of simple cues. A newly discovered cue is the position, mainly in the vertical direction, of the common centre (centroid) of black areas combined together. Significantly, however, the trained bees look for the cues mentioned above only in the range of places where they had occurred during the training. These two observations made possible a synthesis of both theories. There is no experimental evidence that the bees detect or re-assemble the layout of patterns in space; instead, they look for a cue in the expected place. With an array of detectors of the known cues, together with their directions, this mechanism would enable bees to recognize each familiar place from the coincidences of cues in different directions around the head.     

Proteome and phosphoproteome of Africanized and European honeybee venoms

Honey bee venom toxins trigger immunological, physiological, and neurological responses within victims. The high occurrence of bee attacks involving potentially fatal toxic and allergic reactions in humans and the prospect of developing novel pharmaceuticals make honey bee venom an attractive target for proteomic studies. Using label‐free quantification, we compared the proteome and phosphoproteome of the venom of Africanized honeybees with that of two European subspecies, namely Apis mellifera ligustica and A. m. carnica. From the total of 51 proteins, 42 were common to all three subspecies. Remarkably, the toxins melittin and icarapin were phosphorylated. In all venoms, icarapin was phosphorylated at the ²⁰⁵Ser residue, which is located in close proximity to its known antigenic site. Melittin, the major toxin of honeybee venoms, was phosphorylated in all venoms at the ¹⁰Thr and ¹⁸Ser residues. ¹⁸Ser phosphorylated melittin—the major of its two phosphorylated forms—was less toxic compared to the native peptide.     

Specialty oilseed crops provide an abundant source of pollen for pollinators and beneficial insects

The continuing pollinator crisis is due, in part, to the lack of year‐round floral resources. In intensive farming regions, such as the Upper Midwest (UMW) of the USA, natural and pastoral vegetation largely has been replaced by annual crops such as maize (Zea mays L.), soyabean (Glycine max L.) and wheat (Triticum spp.). Neither the energy (nectar) nor protein (pollen) needs of pollinating and other beneficial insects are being met sufficiently by the new, high‐intensity, agricultural landscape. Several potentially useful oilseed crops can be grown in the UMW, and many of these oilseeds are highly attractive to beneficial insects. Prior research showed that some of these oilseeds produced abundant nectar, but their corresponding values for pollen production are unknown. Accordingly, the aim of our research was to document pollen (and protein) production per unit area of twelve oilseed crops grown in Minnesota and associate these values with levels of beneficial insect visitation during anthesis. Our results show that oilseed crops such as camelina (Camelina sativa L.), flax (Linum usitatissimum L.) and pennycress (Thlaspi arvense L.) produce relatively little pollen (≤40 kg/ha); borage (Borago officinalis L.), calendula (Calendula officinalis L.), canola (Brassica napus L.), crambe (Crambe abyssianica Hochst) and cuphea (Cuphea viscosissima Jacq. × Cuphea lanceolata W. T. Aiton) produce bountiful pollen resources (50–150 kg/ha); and oilseed echium (Echium plantagineum L.) generates massive amounts of pollen (>400 kg/ha), about 50% of which is protein. Our study is unique in presenting a season‐long perspective of pollen production in alternative oilseed crops, a resource valuable to pollen‐feeding insects such as managed and wild bees. Diversification of UMW landscapes that includes alternative oilseed crops such as oilseed echium and cuphea can potentially provide a ready source of pollen and protein to help combat pollinator decline.     

Effects of landscape structure and climate seasonality on pollen intake by honeybees in Neotropical highland agroecosystems

1. Pollen is the main protein source for honeybee brood and so colony development relies heavily on the availability of pollen in the environment. Intensification of agriculture and climate seasonality are known to alter honeybee pollen intake in temperate regions through changes in resource availability; however, little is known about how honeybees respond to such environmental factors in tropical regions.
2. Pollen collected by honeybees was sampled from apiaries in a Neotropical highland region of Colombia. Pollen species were identified and the effects of landscape diversity, forest area and mean monthly precipitation on the pollen intake by honeybees were evaluated for all pollen species together and pollen species segregated according to forest and anthropic areas.
3. Honeybees were found to be much more associated with anthropic than forest pollen species regardless of landscape structure or precipitation. However, pollen intake from all species and forest species responded positively to landscape diversity and forest area. Precipitation was found not to be related to the overall amount and overall richness of pollen collected by honeybees. Nonetheless, overall pollen diversity was negatively affected by precipitation in less diverse landscapes, whereas anthropic pollen diversity was negatively affected by precipitation in more forested landscapes.