Bee Bread Samples Research Articles

基于DNA宏条形码技术的蓝彩带蜂粉源植物多样性研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于DNA宏条形码技术的蓝彩带蜂粉源植物多样性研究 DOI: 10.5846/stxb202108102204 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 科技部科技基础资源调查专项（2018FY100405）；国家自然科学基金（31970484）；重庆市科技兴林项目（渝林科研2020-5） Analysis of species and diversities in the pollen plants of Nomia chalybeata (Hymenoptera: Halictidae) using DNA metabarcoding technique Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:蓝彩带蜂（Nomia chalybeate Smith，1875）隶属隧蜂科彩带蜂属，是一种典型的广访花性野生蜜蜂，广泛分布于我国东部地区及日本、韩国、印度、缅甸等国家。本研究基于我国东部9个省份18个不同样地20份蓝彩带蜂蜂粮样本，包括安徽省（AHGZ、AHJZ）、重庆市（CQSMS、CQWS）、福建省（FJSM）、广西省（GXHP、GXLZ）、湖南省（HNHY、HNQY）、海南省（HNLS、HNWC）、江西省（JXGX、JXJG6、JXJG8、JXQY6、JXQY8、JXYZ）、山东省（SDLL）、浙江省（ZJCS）。利用DNA宏条形码研究该蜂粉源植物的多样性，为全面掌握该蜂的粉源植物及保护策略提供理论依据。结果表明该蜂粉源植物共涉及47科，99属，124种，其中黄荆（Vitex negundo）是最优势种、其次是罗伞树（Ardisia quinquegona）和山莓（Rubus corchorifolius）。Alpha多样性指数分析显示：SDLL样本的物种丰富度和多样性最高，FJSM样本的丰富度和多样性最低。不同样地的粉源植物多样性具有差异，但该蜂同一样地不同时期的粉源植物多样性及结构无显著差异，主要粉源植物无变化，表明在同一样地该蜂成虫活动期主要粉源植物的变化不大。 Abstract:Nomia chalybeata is a typical polylectic bee species, belonging to the genus Nomia of the family Halictidae. It is widely distributed in eastern China, Japan, South Korea, India, Myanmar, and other countries. In this study, 20 bee bread samples of N. chalybeata were collected from 18 different places in 9 provinces in eastern China, including Anhui Province (AHGZ, AHJZ), Chongqing City (CQSMS, CQWS), Fujian Province (FJSM), Guangxi Province(GXHP, GXLZ), Hunan Province (HNHY, HNQY), Hainan Province(HNLS, HNWC), Jiangxi Province (JXGX, JXJG6, JXJG8, JXQY6, JXQY8, JXYZ), Shandong Province (SDLL), Zhejiang Province (ZJCS). We studied the diversity in the pollen plants of N. chalybeata based on a DNA metabarcoding, so as to provided theoretical basis for comprehensive understanding the pollen plants and protection strategies. The results showed that there were 47 families, 99 genera and 124 species. Vitex negundo was the most dominant species, followed by Ardisia quinquegona and Rubus corchorifolius. According to the indices of alpha diversity, the species richness and diversity of the sample SDLL were the highest, the sample FJSM were the lowest. The diversity of different sample plot were different. In addition, there was no significant difference in the diversity and structure of pollen plants at different time periods in the same area, and there was no change in the main pollen plants, indicating that the main pollen plants during the adult active period did not change much in the same area. 参考文献 相似文献 引证文献

The Native Dietary Habits of the Two Sympatric Bee Species and Their Effects on Shaping Midgut Microorganisms.

The intestinal microbial community composition of different bee species typically has host specificity, yet little is known about the underlying formation mechanism. There are signs that dietary habits vary in different bee species, suggesting that there may be close relationships between dietary habits and intestinal microorganisms. We explored this hypothesis by comparing the dietary habits and gut microbiota of two common bee species (Apis mellifera L. and Apis cerana cerana) in China. Bee bread and midgut samples from wild and laboratory-reared bees were collected, and the differences in intestinal microbial community composition and growth and development before and after the change in dietary habits of different bee species were compared. We found that the two sympatric species had different dietary specializations and similar metagenomic diversities. The microbiota composition differed between the two species. Moreover, we revealed that changes in native dietary habits destroyed the intestinal microbiota community composition, negatively affecting the growth and development of honeybees.

Chemical Profile, Antioxidant Properties and Antimicrobial Activities of Malaysian Heterotrigona itama Bee Bread.

The aim of the study was to determine the chemical profile, antioxidant properties and antimicrobial activities of Heterotrigona itama bee bread from Malaysia. The pH, presence of phytochemicals, antioxidant properties, total phenolic content (TPC) and total flavonoid content (TFC), as well as antimicrobial activities, were assessed. Results revealed a decrease in the pH of bee bread water extract (BBW) relative to bee bread ethanolic extract (BBE) and bee bread hot water extract (BBH). Further, alkaloids, flavonoids, phenols, tannins, saponins, terpenoids, resins, glycosides and xanthoproteins were detected in BBW, BBH and BBE. Also, significant decreases in TPC, TFC, DPPH activity and FRAP were detected in BBW relative to BBH and BBE. We detected phenolic acids such as gallic acid, caffeic acid, trans-ferulic acid, trans 3-hydroxycinnamic acid and 2-hydroxycinnamic acid, and flavonoids such as quercetin, kaempferol, apigenin and mangiferin in BBE using high-performance liquid chromatography analysis. The strongest antimicrobial activity was observed in Klebsilla pneumonia (MIC50 1.914 µg/mL), followed by E. coli (MIC50 1.923 µg/mL), Shigella (MIC50 1.813 µg/mL) and Salmonella typhi (MIC50 1.617 µg/mL). Bee bread samples possess antioxidant and antimicrobial properties. Bee bread contains phenolic acids and flavonoids, and could be beneficial in the management and treatment of metabolic diseases.

Miniaturized multiresidue method for determination of 267 pesticides, their metabolites and polychlorinated biphenyls in low mass beebread samples by liquid and gas chromatography coupled with tandem mass spectrometry

Current work presents developed and validated miniaturized method for residue analysis of 261 pesticides and their metabolites as well as 6 congeners of non-dioxin like polychlorinated biphenyls (ndl-PCB) in a very low mass beebread sample. Sample preparation is based on modified QuEChERS protocol with all steps miniaturized to enable multiresidue analysis of sample with extremely low weight. Sample of beebread (0.3 g) was extracted with 1 mL of acetonitrile containing 5% formic acid and ammonium formate salt were added, then extract was subjected to clean-up by freezing and two-step dispersive solid phase extraction (dSPE) with a Supel QuE Verde sorbents (Supelclean ENVI-Carb Y; Supelclean PSA; Z-Sep+; magnesium sulfate). After 1st step dSPE a portion of extract was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for 200 pesticide residues. Remaining extract was subjected to 2nd step dSPE clean-up by another Supel QuE Verde and then after concentration and solvent exchange it was analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS) for another 61 pesticide and 6 ndl-PCB residues. Method enables determination of residues of 101 insecticides, 72 herbicides, 67 fungicides, 10 acaricides, 6 growth regulators, 5 veterinary drugs and 6 ndl-PCB's. Particular attention was paid to the pesticides being active substances of plant protection products recommended for the protection of winter oilseed rape and apple orchards which during their blooming periods are one of the most attractive sources of food for pollinators and could serve as representatives of other economically important crops. Method was validated according to the Guidance document SANTE/12682/2019 at six concentration levels from 0.001 to 0.5 mg kg−1. The analysis of beebread samples spiked at the level of 0.01 mg kg−1showed mean recovery (trueness) value of about 98% and RSDr (precision) below 20%. The small weight of the sample did not adversely affect the limits of quantification and 75% of analytes could be quantified at least at concentration of 0.005 mg kg−1. Developed mini-method was tested in the analysis of beebread samples, each extracted from individual cell of honeycomb. It is the first time when analyses at single comb cell level were possible.

Presence, persistence and distribution of thymol in honeybees and beehive compartments by high resolution mass spectrometry

Thymol has been considered as an organic varroacide with less toxicity than synthetic chemicals such as amitraz, coumaphos or tau-fluvalinate. The present study evaluates the presence, persistence and distribution of thymol during a five-month sampling period; before, during and after the application of thymol treatment in field conditions. Moreover, its impact on the development of bee brood was also studied at different development stages which consist of larvae, prepupae, pupae and adult honeybee. Samples of beebread (processed pollen), honey, beeswax, adult bees, pupae, prepupae and larvae were analysed by gas chromatography coupled to time of flight mass spectrometry for an accurate identification. Adult bees were the samples with the highest concentration level of thymol during treatment application (Thymovar® strips, 30 gr of thymol per hive) by the beekeeper, however they showed 69% of thymol dissipation three months after treatment. Regarding the bee brood, concentrations of thymol decreased significantly (89-97% of disappearance) in a period of three months, though about 42 µg/kg of thymol persisted in larvae. Thymol was found to accumulate in honey and beeswax at a level of 882 μg/kg and 1305 μg/kg respectively, in the studied period. As the main issue of thymol residues in honey is related to the modification of organoleptic properties, more than toxicology, the levels found in this study indicate that the taste of honey may be affected during and up to three months after the treatment application. In addition, we did not find adverse effects on the evolution of the colonies due to the applied treatment.

Agrochemical Contamination of Honey and Bee Bread Collected in the Piedmont Region, Italy

This study shows the results of a local biomonitoring plan developed by a regional beekeeping association, Aspromiele, in several areas of Piedmont (Italy), in order to understand the status of contamination from pesticides present in the environment and eventually to evaluate their impact on apiculture. Glyphosate was the most abundant chemical found in the bee bread and honey samples. The other pesticides detected at lower concentrations and minor frequency were mandipropamid, tau-fluvalinate, metalaxil and spiroxamine. Even if in the present study the pesticides found in the bee bread and honey were limited to a few molecules, it is important to highlight that the presence of glyphosate could represent a hazard to bees. Honeybees are the main pollinators in agricultural ecosystems, and thus appropriate environmental management could lead to a reduction in the impact of these chemicals on bees and other beneficial insects.

Bee Pollen and Bee Bread as a Source of Bacteria Producing Antimicrobials.

The principal objective of the study was the isolation and identification of bacteria that are present in mature bee bread (BB) and dried (ready for selling and consumption) bee pollen (BP). Obtained isolates were screened for their potential to inhibit select human pathogenic bacteria and their ability to produce enzymes of particular industrial importance. Four and five samples of BP and BB, respectively, were used for the study. In total, 81 strains of bacteria were isolated, and 34 (42%) of them exhibited antagonistic interactions with at least one reference strain of pathogenic bacteria, namely Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis 12228, Pseudomonas aeruginosa ATCC 27857, and Escherichia coli ATCC 25922. The sequencing of the 16S rRNA gene revealed that all strains producing antimicrobials belong to the genus Bacillus spp., and among them, five species were identified: B. pumilus (n = 17), B. altitudinis (n = 9), B. licheniformis (n = 4), B. subtilis (n = 2), and B. safensis (n = 1). Furthermore, 69, 54, 39, and 29 of the strains exhibited lipolytic, proteolytic, cellulolytic, and esterolytic activity, respectively. Alpha amylase and beta galactosidase activity were rarely observed, and none of the strains produced laccase. The outcomes of the study revealed that BP and BB can be considered potential sources of bacteria producing antimicrobial agents and/or enzymes of particular industrial importance. Of course, additional research is required to verify this hypothesis, but the results of preliminary studies are promising.

The composition of bacteria in gut and beebread of stingless bees (Apidae: Meliponini) from tropics Yunnan, China.

Stingless bees are the main pollinators in tropical and subtropical regions. However, there are only a few studies on the structure and composition of bacteria in the gut and beebread of stingless bees, especially in China. To address this shortage of information, we characterized the microbiota of three common species of stingless bees (Lepidotrigona terminata, Lepidotrigona ventralis and Tetragonula pagdeni) and beebread samples of T. pagdeni. The results showed that the gut of stingless bees contained a set of dominant bacteria, including Acetobacter-like, Snodgrassella, Lactobacillus, Psychrobacter, Pseudomonas, Bifidobacterium and other species. The gut microbiota structures of the three stingless bees were different, and the abundances of bacterial species in the gut varied between communities of the same bee species. The reasons for this are manifold and may include food preference, age and genetic differences. In addition, the abundances of Lactobacillus, Carnimonas, Escherichia-Shigella, Acinetobacter and other species were high in the beebread of stingless bees. In conclusion, our findings reveal the bacteria composition and structure of the gut and beebread of stingless bees in China and deepen our understanding of the dominant bacteria of the gut and beebread of stingless bees.

Findings of herbicide and fungicide residues in bee bread

The honey bee is one of the insects that is significantly endangered by the application of pesticides in the cultivation of crops. Not only is acute toxicity dangerous, but the importance of chronic poisoning by low doses of pesticides in hives is growing. The behavior of bees can be affected not only by insecticide residues but also by herbicide and fungicide residues. In 2016–2018, samples of bee bread were analysed for pesticide content at 25 different localities from intensive agricultural production areas of the Czech Republic. Substances were extracted by QuEChERS and determined by liquid chromatography, together with mass spectrometric detection. We detected up to 18 pesticides in one sample. In total, during 2016–2018, we identified 53 active substances. Fifteen substances (31%) were herbicidal, 23 substances (47%) of fungicidal nature and 6 substances (12%) of insecticidal nature. The coefficient of variation showed large differences in the frequency of revealed pesticides between years. For substances sprayed outside period attractive for pollinators (mainly herbicides and some fungicides), the usual methodology cannot reliably determine the degree of contamination, and thus the actual contamination with these substances may be even higher than demonstrated in this study.

Biological Properties of Bee Bread Collected from Apiaries Located across Greece.

Bee bread is the only fermented product of the beehive. It constitutes the main source of proteins, lipids, vitamins, and macro- and microelements in honeybee nutrition and it exerts antioxidant and antimicrobial properties, though research on these aspects has been limited so far. In this study 18 samples of Greek bee bread, two of which were monofloral, were collected during different seasons from diverse locations such as Crete and Mount Athos and were tested for their bioactivity. Samples were analyzed for their antibacterial properties, antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC). The antimicrobial activity of each sample was tested against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella typhimurium. Our data demonstrate that all samples exert inhibitory and most of them bactericidal activity against at least two pathogens. Furthermore, all samples exert significant antioxidant activity, where the monofloral Castanea Sativa sample demonstrated superior antioxidant activity. Nevertheless, the antioxidant and antimicrobial activity were not strongly correlated. Furthermore, machine learning methods demonstrated that the palynological composition of the samples is a good predictor of their TPC and ABTS activity. This is the first study that focuses on the biological properties of Greek bee bread and demonstrates that bee bread can be considered a functional food and a possible source of novel antimicrobial compounds.

Detection of fructophilic lactic acid bacteria (FLAB) in bee bread and bee pollen samples and determination of their functional roles

In this study, bee bread and bee pollen samples were characterized in terms of presence of fructophilic lactic acid bacteria (FLAB). Following discrimination and identification of FLAB strains, their functional roles were determined. Genotypic characterization of FLAB strains revealed the presence of 27 distinct strains belonging to Lactobacillus kunkeei (21), Fructobacillus fructosus (3), Lactobacillus plantarum (2), and Leuconostoc mesenteroides (1) strains. In terms of functional roles, all FLAB strains demonstrated high levels of autoaggregation and hydrophobicity properties whereas L. kunkeei and F. fructosus strains did not tolerate bile salts and low pH conditions. A low level of antibiotic resistance was observed among FLAB strains and importantly FLAB strains demonstrated high levels of antibacterial and antifungal activities where strain specific properties played roles. The highest exopolysaccharide (EPS) production yields were obtained for L. kunkeei AP15, AP37 and L. mesenteroides AP-40 which produced 2.79, 2.01, and 5.37 g/L EPS, respectively. Practical applications Bee bread and bee pollen are among beneficial bee products produced and consumed in all over the world. Production of bee bread relies on the fermentation process of bee pollen where a special LAB group FLAB plays roles. Despite the increment of the importance of these products for human consumption, there is a lack of knowledge for the microbial composition of these products. In this study, FLAB strains were isolated and identified from bee bread and bee pollen samples, and their technofunctional role was determined. The FLAB strains would be evaluated as starter cultures for production of bee products under industrial conditions.

Pollen and Chemical Content of Beebreads from Serpentine Areas in Albania and Bulgaria.

Beebread from serpentine localities in Albania and Bulgaria were characterized based on their pollen and chemical element content (macroelements K, Ca, Mg, P and microelements Cd, Co, Cr, Cu, Fe, Mn, Na, Ni, Pb, Zn) aiming to (1) evaluate the effect of serpentine soil on the quality of beebread; (2) compare elemental concentrations in samples from serpentine areas in Albania and Bulgaria; and (3) compare the differences in pollen spectra. Chemical element content was determined using microwave digestion of beebread samples followed by ICP-OES measurements. The analytical procedure developed was validated by added/found method. Analytical figures of merit of analytical method proposed were presented. The melissopalynological analysis was applied for pollen characterization. The results demonstrate clear difference in the pollen spectra between the two sets of samples, confirming differences in local serpentine flora in both countries, but specific pollen type is difficult to be suggested. The pollen content is related to the flowering period, climatic conditions, and bees forage preferences. The samples vary in their elemental concentrations depending on the pollen type and year of collection. The highest average concentrations found for K, Ca, Mg, and P are close to values reported in the literature. However, elevated concentrations observed for Ni, Cr, Mn, and Fe in beebread, especially from Albania, are in line with the serpentine characteristics of studied areas. The concentrations of Cd and Pb for all beebread samples are below permissible limits. The results should be taken into consideration in future specific food safety regulations at national and international level.

Botanical origin approach for a better understanding of chemical and nutritional composition of beebread as an important value-added food supplement

Beebread (BB) is a fermented bee product made from plant pollen, honey and bee saliva. The nutritive and biological compounds of BB vary greatly depending on the diversity of flora and the season of pollen collection by bees. In order to evaluate this valuable bee product potential, thirteen BB samples were analyzed on the nutritive proprieties and biologically active compounds, correlated with their botanical origin. The obtained results shows that BB comes with a high content of proteins with values ranging between 18.96 and 23.11 g/100 g, lipids ranging between 4.89 and 14.74 g/100 g, and free sugars, fructose being present in the highest amount (17.27 g/100 g). Analyzed samples contain all the essential amino acids, methionine being the most abundant, 86.93–12.38 mg/100 g, mono- and polyunsaturated fatty acids, ω-6/ω-3 ratio varying between 0.02 – 1.07. BB samples have also high amount of natural antioxidants, from the class of polyphenols and flavonol glycoside derivative. These findings suggest that BB could be used as a source of potential value-added nutrients and bioactive compounds and contributes to the chemical knowledge of this natural product.

Bee Bread Exhibits Higher Antimicrobial Potential Compared to Bee Pollen.

This study aimed at investigation of the antimicrobial potential of ethanolic extracts of bee bread (BB) and bee pollen (BP) and suspensions of these products in MHB (Mueller Hinton Broth). We covered 30 samples of BP and 19 samples of BB harvested in Polish apiaries. Slightly lower activity was observed against Gram-negative bacteria compared to Gram-positive staphylococci. BB extracts exhibited higher inhibitory potential with minimum inhibitory concentration (MIC) values in the range from 2.5 to 10% (v/v) against Staphylococcus aureus ATCC 25923 and ATCC 29213. Most active BB extracts, namely, BB6, BB11 and BB19, effectively inhibited growth of clinical isolates of S. aureus (n = 9), including MRSA (methicillin resistant Staphylococcus aureus) strains (n = 3) at concentrations ranging from 2.5 to 5.0% (v/v). Minimal bactericidal concentration (MBC) values were in the same range of concentrations; however, a shift from 2.5 to 5.0% (v/v) was observed for some products. The most active BP extracts inhibited the growth of reference strains of S. aureus at a concentration of 5% (v/v). Up to the concentration of 20% (v/v) three and seven BP extracts were not able to inhibit the growth of S. aureus ATCC 29213 and S. aureus ATCC 25923 respectively. The growth of staphylococci was also importantly inhibited in suspensions of the products in MHB. No correlation between phenolic content and antimicrobial activity was observed.

Phenolic and free amino acid profiles of bee bread and bee pollen with the same botanical origin – similarities and differences

In this study, the chemical profile of bee pollen (BP) and bee bread (BB) samples collected from the same beehive were analyzed by LC–MS/MS (liquid chromatography technique coupled with tandem mass spectrometry), providing the identification of 23 phenolic compounds and 42 free amino acids (FAAs). Rutin was the phenolic compound with the highest rate of occurrence in both BP and BB samples. However, concentrations of protocatechuic acid, 2,5-dihydroxybenzoic acid and kaempferol compounds were significantly higher in BB samples than in BP samples from the same hive probably as result of microbial activity and glycosides degradation. The obtained data revealed that the phenolic profiles of the samples differ not only by the type of a product but also by region. Among FAAs proline was the predominant compound in all the analyzed BP and BB samples followed by l-asparagine (BP samples) and l-aspartic acid (BP and BB samples). A high content of proline can be used as a parameter of sample freshness. Also, Principal Component Analysis (PCA) and Cluster analysis proved the possibility of using phlorizin as a chemotaxonomic marker for Rosaceae (Malus or Prunus genus) pollen presence in BP1 sample. In addition, amino acid profile had higher impact on BP and BB sample differentiation due to lower FAAs content in BB samples probably caused by microbial activity. To the best of our knowledge, this study is the first to compare the individual phenolic compounds and free amino acids of bee pollen and bee bread samples with the same botanical origin (predominantly originated from plants belonging to the following families: Asteraceae, Fabaceae, Plantaginaceae and Rosaceae).

The influence of storage conditions on invertase, glucose oxidase activity and free acidity of bee bread and bee-collected pollen mixed with honey and vegetable oils

The aim of this study was to develop mixtures of bee bread and pollen with linseed oil, sea buckthorn oil, royal jelly, and algae Spirulina (Spirulina platesnis) and to determine the impact of vegetable oils on invertase and glucose oxidase activity, free acidity and the influence of storage conditions on enzyme activity in the tested products. The influence of storage conditions and duration was determined by evaluating the correlation between invertase and free acidity in the bee products of known botanical origin supplemented with the tested additives. The influence of additives on the bioactive properties was tested in 14 combinations of mixtures and in pure bee bread and pollen. The highest relationship between free acidity and invertase activity (r = − 0.619) was determined for bee bread samples with additives stored at room conditions. According to the data of paired regression between free acidity and invertase activity, the correlation coefficient was (r = −0.747) for pure bee bread stored at +4–5 °C and for that stored at room conditions (r = −0.972).

Pollen sources of Tetragonula biroi (Friese, 1898) (Hymenoptera: Apidae, Meliponini) in two agroecosystems in Nagcarlan, Laguna, Philippines

Bee bread samples from the hives of Tetragonula biroi managed in agricultural and agroforest sites in Nagcarlan, Laguna, Philippines were analyzed through light microscopy during the wet season from June to November. A total of 31 pollen types, belonging to 20 botanical families were identified as pollen sources of T. biroi. Adonidia merrilli Becc. and Cocos nucifera L. were consistent predominant pollen sources (>45%) in both sites. The other predominant pollen types in the agricultural site were Arecaceae type 1, Fabaceae type and Marantaceae type, and Ipomoea sp. in the agroforest site. A decreasing number of pollen types were observed from early to late wet months of the study period. Though both sites provide a wide array of pollen sources for T. biroi, the presence of long-blossoming crops resulted in the homogenization of pollen types in the hive. This study highlights the importance of crop diversity and surrounding natural vegetation in the agricultural landscape in providing various pollen sources for pollinators like T. biroi.

A three-year large scale study on the risk of honey bee colony exposure to blooming sunflowers grown from seeds treated with thiamethoxam and clothianidin neonicotinoids

Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control. Each colony was assessed at six moments: one before to exposition to sunflower, two during the exposition (short-time risk), two after exposition (medium-time risk) and one after wintering (long-time risk). The health and development of the colonies were assessed by monitoring adult bee population, brood development, status of the queen, food reserves and survival. No significant difference among treatments when raw data was considered. However, when evolution from initial status of the colony was evaluated, a significant difference was observed from the first week of exposure to sunflower blooms. In this period, the number of adult bees and the amount of brood were slightly lower in the bee hives exposed to neonicotinoids, although such differences disappeared in subsequent evaluations. The concentration of residues in samples of beebread and adult bees was at the level of ng·g−1. Magnitude of the effect of the treatment factor on the variability of colony health and development related parameters was low. The most important factor was the hive, followed by the replicate and year, and to a lesser extent the initial strength of the colonies.

Landscape factors influencing honey bee colony behavior in Southern California commercial apiaries

Colony brood levels, frames of bees (adult bee mass) and internal hive temperature were monitored for 60 colonies for each of two years as they were moved from agricultural, tree crop and mountain landscapes in southern California to blueberry and almond pollination sites. Hive weight was also continuously monitored for 20 of those hives for 6 weeks for both years, during commercial pollination. Pesticide residues in wax, honey and beebread samples were analyzed by composite apiary samples. While colonies in mountain sites had more adult bees and brood than those in agricultural sites in August, by October brood levels were higher in colonies from agricultural sites. Though hives from different original landscapes differed in size in October, hive assessments revealed no differences between the groups after co-wintering when graded for commercial almond pollination. Beebread from hives in agricultural sites had greater agrochemical diversity and in general higher pesticide hazard quotients than those from mountain sites, but those hives also had higher and more constant temperatures from September until January than hives from mountain sites. Hives placed in commercial almond pollination gained on average 287 g per d, compared to an average loss of 68 g per d for colonies in commercial blueberry pollination, although weight data indicated greater foraging effort by colonies in blueberries, possibly due to the proximity and abundance of almond pollen during bloom. Temperature monitoring was effective at distinguishing hive groups and had the best overall value in terms of equipment, installation, colony disturbance and information yield.

Bee bread and bee pollen of different plant sources: determination of phenolic content, antioxidant activity, fatty acid and element profiles

This study aims to determine the plant sources, fatty acid composition, total phenolic-flavonoid content, antioxidant capacity, and elemental profile of bee pollen (BP) and bee bread (BB) samples from the same bee hive in different locations. 31 families and 71 species were determined by pollen analysis of BP and BB samples. Pollen frequencies in BB samples were generally similar or less than in BP. Total phenolic varied from 8.26 ± 0.299 to 43.42 ± 0.779 mg GAE/g, and total flavonoid ranged from 1.81 ± 0.040 to 4.44 ± 0.125 mg QE/g. ABTS and DDPH assays indicated that the samples have good antioxidant activity. Samples showed a protein content ranging from 17.6 to 22.2% while the total fatty acid was between 60.27 and 86.49%. The elemental analysis showed that all samples were rich in essential minerals. As a result, total protein, total fatty acids, moisture content and antioxidant capacity of BB samples were found to be lower than those of BP samples from the same hive. In spite of these data, it is necessary to work with more detailed and more samples to be able to say which bee product (bee pollen or bee bread) has superior properties as functional food.