Pollen Load Samples Research Articles

Application of 3D-printed pollen traps as a useful tool for exposure and risk assessment of pesticide residues on bumblebees

The study was designed to test the feasibility of using 3D-printed pollen traps for long-term monitoring of Bombus terrestris colonies' exposure to pesticide residues in pollen loads collected by them, along with an assessment of the resulting risks to the bumblebee's adults, larvae, and queens. Bumblebee colonies were placed in the vicinity of flowering orchards, winter oilseed rape, allotments, or home gardens for 6 weeks of the experiment. Pollen traps printed in 3D technology were installed in the hive inlets. The weight of bumblebee pollen loads obtained using pollen traps was in the range of 0.036–5.83 g. Pollen load samples were analyzed for residues of up to 261 pesticides and their metabolites by liquid and gas chromatography techniques coupled to tandem mass spectrometry (LC-MS/MS and GC-MS/MS). Residues of 18 fungicides, 12 herbicides, 6 insecticides, and an acaricide were detected. Herbicide – pendimethalin, fungicide – thiophanate-methyl, and insecticide – chlorpyrifos-ethyl were the most commonly detected pesticides. Chlorpyrifos and thiacloprid residues were detected in pollen load samples in the next year after their ban from use as plant protection products in the European Union. The risk of acute or chronic effects was assessed as negligible or low, although the chronic risk of bumblebee queens to insecticide chlorpyrifos and the acute risk of larvae exposed to acaricide fenpyroximate could be interpreted as moderate. The risk of sublethal effects related to chronic exposure of adult bumblebees and queens to pollen loads contaminated by chlorpyrifos-ethyl and cypermethrin cannot be excluded. The risk of chronic toxicity or sublethal effects may be particularly relevant for bumblebee queens, especially during their foraging in the initial period of establishing a new colony.

Temporal and spatial variation of pollen content in pollen loads of Apis mellifera in the Yungas of northwest Argentina

The floral resources used by Apis mellifera as pollen source include those present in natural forests like the Yungas as well as forested areas. The aim of this work was to determine the main pollen resources harvested by A. mellifera and their variation during the honey production season. Forty pollen load samples were randomly collected from apiaries located in four sites (Tilquiza, El Fuerte, Los Alisos and Los Toldos) in spring and summer between 2011 and 2017. Sampling was conducted using pollen traps and the samples were subjected to conventional melissopalynological techniques. Pollen sources were identified using palynological atlases and compared with the reference palynotheca. A total of 70 pollen types distributed in 39 botanical families were identified, with the following families having the highest index of family importance (IF): Asteraceae (23.9), Fabaceae (19), Myrtaceae (12.8), Poaceae (8.3), Euphorbiaceae (8.2) and Vitaceae (4.3). The main resources used were: Mimosa, Eupatorium, Blepharocalyx salicifolius, Baccharis and Sebastiania. A pollen diagram was used to analyze the different pollen resources used throughout the study seasons. Species foraged in spring included B. salicifolius, Anadenanthera colubrina, Parapiptadenia excelsa and Sebastiania and those foraged in summer included Mimosa, Viguiera, Type Cissus and species of the family Poaceae; all of these species are native to the forest. The present results contribute to the knowledge of polliniferous species of the Yungas and evidence the importance of this bee as flower visitor in the forest.

Fizikalno-kemijske karakteristike i antioksidativni kapacitet peludi prikupljene na području tuzlanskog kantona (BiH)

The aim of this research was to evaluate bee pollen load samples collected in Tuzla Canton regarding physicochemical composition and antioxidant properties, with relation to collecting area and time of collection. Bee pollen load samples were collected in two periods: March/April and May/June at 13 locations, dried and analysed for protein, free fat, ash, moisture, total polyphenol and total flavonoid content, and antioxidant properties. The results showed that bee pollen collected in March/April had lower content of proteins, but higher content of total polyphenols and higher antioxidant activity, while total flavonoid content was not influenced by collection period. The location had significant influence on bee pollen properties.

Pollen sources in the Bojanów forest complex identified on honeybee pollen load by microscopic analysis

<p>The aim of this study was to determine sources of pollen for the honeybee in the Bojanów forest complex, Nowa Dęba Forest District (southeastern Poland). Sampling of pollen loads from bees extended from the beginning of May until the end of September 2016 and was carried out at 7-day intervals using pollen traps mounted at the entrance of beehives. A total of 73 pollen load samples were collected from the study area.</p><p>Fifty-nine taxa from 31 plant families were identified in the analyzed material. From 4 to 21 taxa (average 9.5) were recorded in one sample. The pollen of Brassicaceae (“others”), <em>Taraxacum</em> type, <em>Solidago</em> type, and <em>Rumex</em> had the highest frequency in the pollen loads examined. Apart from these four taxa, pollen grains of <em>Rubus</em> type, Poaceae (“others”), <em>Calluna</em>, <em>Fagopyrum</em>, <em>Trifolium repens</em> s. l., <em>Phacelia</em>, <em>Aster</em> type, <em>Melampyrum</em>, <em>Quercus</em>, <em>Cornus</em>, and <em>Veronica</em> were recorded in the dominant pollen group. The forest habitat taxa that provided pollen rewards to honeybees in the Bojanów forest complex were the following: <em>Rubus</em>, <em>Calluna</em>, <em>Prunus</em>, <em>Tilia</em>, <em>Frangula alnus</em>, <em>Pinus</em>, <em>Quercus</em>, <em>Cornus</em>, <em>Robinia pseudoacacia</em>, <em>Salix</em>, and <em>Vaccinium</em>. Apart from forest vegetation, the species from meadows and wastelands adjacent to this forest complex, represented by <em>Taraxacum</em>, <em>Rumex</em>, <em>Plantago</em>, Poaceae, <em>Trifolium repens</em>, and <em>Solidago</em>, proved to be an important source of pollen. The study indicates that forest communities are a valuable source of pollen for pollinating insects from early spring through to late fall.</p>

Application of HPLC-DAD Technique for Determination of Phenolic Compounds in Bee Pollen Loads

Abstract A method was elaborated to determine phenolic compounds (vanillin, caffeic, p-coumaric and salicylic acids, and flavonoids: rutin, hesperetin, quercetin, pinocembrin, apigenin, kaempferol, isorhamnetin, chrysin, and acacetin) in bee pollen loads using highperformance liquid chromatography with a diode array detector (HPLC-DAD). Phenolic compounds from bee pollen were isolated on Cleanert C18-SPE columns (500 mg/6 mL, Agela Technologies). Polyphenols were identified by comparing the retention times and spectra of compounds found in pollen load samples with the ones of the standard mixture. Quantitative analysis was conducted using the external standard method. In addition, basic validation parameters for the method were determined. For the identified compounds (except for the salicylic acid), satisfactory (≥0.997) linear correlations were obtained. The elaborated method showed high repeatability and inter-laboratory reproducibility. Variability coeffcients of the majority of phenolic compounds did not exceed 10% in conditions of repeatability and inter-laboratory reproducibility, and for the total polyphenolic content they were 1.7 and 5.1%, respectively. The pollen load samples (n = 15) differed in qualitative and quantitative composition of the phenolic compounds. In all the samples, we identified the p-coumaric and salicylic acids and flavonoids rutin, hesperetin, and apigenin nevertheless, these compounds’ contents significantly differed among individual samples. The total phenolic content in the tested samples of pollen loads ranged from 0.653 to 5.966 mg/100 g (on average 2.737 mg/100 g).

Análisis palinológico de mieles y cargas de polen de <em>Apis mellifera</em> (Apidae) de la región Centro y Norte del estado de Guerrero, México

The present work is a contribution to knowledge of polen recovered from six Apis mellifera honey samples and six pollen loads samples, in order to characterize their botanical and geographical origin. Samples were collected from central and northern Guerrero -both regions of beekeeping importance during November-December 2005 and March 2006. Honeybee foraging behavior was also analyzed. Melissopalynological results showed a total of 43 pollen types belonging to 27 families; only 15 taxa of native flora were considered of importance, and their palynological descriptions are included: Cosmos sulphureus, Dyssodia papposa, Taraxacum campylodes, Tithonia tubaeformis, and Vernonia sp. (Asteraceae), Coutoubea sp. (Gentianaceae), Dalea sp. and Leucaena leucocephala (Fabaceae), Quercus sp. (Fagaceae), Miconia sp. (Melastomataceae), Pisonia sp. (Nyctaginaceae), Dodonaea viscosa and Paullinia sp. (Sapindaceae), Solanum sp. Solanaceae), and Heliocarpus donnellsmithii (Malvaceae) as well as Zea mays (Poaceae), an abundant crop. Two oligofloral and four multifloral honey samples were characterized. Diversity indexes varied from 1.7 to 2.3 in honey samples, while the pollen loads registered 1.6 to 2.1values in diversity, the evenness index in honey samples varied from 0.8 to 0.9, whereas pollen load samples registered a range from 0.6 to 0.9. Apis mellifera showed polylectic behavior; the herbaceous stratum was the most foraged, followed in importance by tree and shrub strata.

Melissopalynology studies on the Indian honey bee (Apis cerana indica Fab.) in southern Kerala

Melissopalynology studies of the Indian honey bee (Apis cerana indica Fab.) in southern Kerala was undertaken to study the potential pollen and nectar sources of Indian honey bee across the seasons in southern Kerala. A detailed characterization of all the honey and pollen samples showed the presence of 69 different pollen types; of which twenty four pollen types were identified up to species level. They were distributed among 19 families of these, the pollen types from the families of Arecaceae (3) and Asteraceae (3) were best represented in honey and pollen load samples. Honey bees were found to collect pollen from the tall trees (Cocos nucifera) as well as the small plants (Mimosa pudica) irrespective of their height.

Pollen Foraging by Honey Bees (Apis Mellifera L.) in Greece: Botanical and Geographical Origin

Abstract Pollen is very important for honey bee colony development and nutrition. It is also a valuable product for human consumption, considered to have high nutritional value. In this study, we performed melissopalynological analysis of 285 pollen load samples collected from 44 apiaries throughout Greece. The analysis revealed 229 plant taxa represented in total. The abundance of each pollen type varied among the geographical areas from which the samples were collected. We also observed variation among samples collected from the same geographical region. The most frequently found families were Fabaceae, Asteraceae and Rosaceae. The most frequently observed taxa were Brassicaceae, Carduus type, Cistus and Papaver rhoeas. Statistical analysis showed that the geographical classification of pollen samples among northern, central and southern Greece is possible.

Effects of exposure of honey bee colonies to neonicotinoid seed–treated maize crops

Abstract The effects to honeybee colonies (Apis mellifera L.) during and after exposure to flowering maize (Zea mays L.), grown from seeds coated with clothianidin and imidacloprid was assessed in field-realistic conditions. The experimental maize crops were adjacent to the other flowering agriculture plants. Honey bee colonies were placed in three differently protected maize fields throughout the blooming period, and thereafter they were transferred to a stationary apiary. Samples of pollen loads, bee bread, and adult bees were collected and analyzed for neonicotinoid residues. To ensure high specificity and sensitivity of detection of the analyzed pesticides, a modified QuEChERS extraction method and liquid chromatography coupled with tandem mass spectrometry were used. Clothianidin was detected only in the samples of pollen loads. Their residue levels ranged from 10.0 to 41.0 ng/g (average 27.0 ng/g). Imidacloprid was found in no investigated sample. No negative effects of neonicotinoid seed-treated maize on the development and long-term survival of honey bee colonies were observed. The low proportion of Zea mays pollen in total bee-collected pollen during the maize flowering period was noted. The findings suggest that maize plants are less attractive forage for honey bees than phacelia (Phacelia tanacetifolia Benth.), buckwheat (Fagopyrum Mill.), white clover (Trifolium repens L.), goldenrod (Solidago L.), and vegetation from Brassicaceae family. The results indicate a possibility of reducing the risk of bees being exposed to the toxic effect of insecticidal dusts dispersed during maize sowing by seeding, in the areas surrounding maize crops, plants that bloom later in the year.

Estimation of the polleniferous potential of a Mediterranean landscape through the analysis of pollen harvested by Apis mellifera L.

The aim of this study was to estimate the polleniferous potential of the most common plant communities and crops across the landscape through the study of pollen loads collected by Apis mellifera. We analysed pollen load samples from hives located in Mallorca (western Mediterranean) for one year and compared the results with a phytosociological study of the foraging area. We also analysed meteorological data to evaluate the influence of some environmental factors on the pollen production phenology. We identified 74 different pollen types (66.2% from native flora, 25.7% from exotic flora, and 8.1% from crops) belonging to 33 families. The highest polleniferous potentials in the landscape were attained by sclerophyllous forests (Quercetea ilicis) in spring, crops in autumn, wild annual rangelands (Stellarietea mediae) in winter and gardens in late summer. Our results suggest that the higher the coverage present in a vegetation class, the higher the quantity and diversity of pollen that may be provided to pollinators; therefore, its polleniferous potential may be higher. Some meteorological conditions (rainfall, temperature and daily hours of sunlight) may affect this potential through their influence on flowering phenology.

Scanning Electron Microscopic Studies on Surface Pattern of the Pollen Loads from Apis cerana in Jajarkot District

Over nineteen species of pollen flora belonging to thirteen families were recovered from four pollen load samples from honey bee Apis cerana collected in Jajarkot district, mid-western region, Nepal. The pollen morphology was investigated using light microscopy along with scanning electron microscopy for correct identification of pollen to its lower taxonomic level and to contribute to melissopalynological studies originating from the native apiflora. The palynological assemblage identified to the generic and some up to species level belong to Alnus sp., Artemisia sp., Brassica sp., Cornus sp., Diploknema sp., Fraxinus sp., Ilex sp., Jasminum sp., Justicia sp., Ligustrum sp., Myrica esculenta, Salix sp., Strobilanthes sp., and Urtica sp. Some of the pollen grains identified to only family level, belong to, Acanthanceae, Compositae, Lamiaceae and Rosaceae. The identified pollens clearly reflect the botanical and geographical origins of the pollen load samples. Palynomorphological investigation included the description of pollen symmetry, polarity, ornamentation, aperture, shape and size. The results for the pollen assemblages and nectariferous plant sources of Jajarkot district are discussed.DOI: http://dx.doi.org/10.3126/njst.v12i0.6522 Nepal Journal of Science and Technology 12 (2011) 340-349

Analysis of protein content in pollen loads produced in north-west Spain

An analysis was made of the protein content of pollen loads produced by the bees in a hive situated in Viana do Bolo (Ourense, north-west Spain), to establish whether or not the relative quantity of protein in the pollen of each plant species influences the preference made by the bee of the flowers that supply pollen to the hive. This analysis was performed on all types of pollen that formed more than 5% of the pollen spectrum. Pollen load samples were collected directly from the hive from March to September. Pollen loads were separated by colour, and their specific homogeneity was confirmed microscopically. The Bradford method has been used for protein extraction and spectrophotometry was used for the determination of protein content. The results show that the different pollen loads have high protein content. Pollen of the plant species that reached relatively higher percentages in the pollen spectrum are also those that have the highest protein content. These were Cytisus scoparius type, uncultivated Poaceae, Quercus robur type, Sanguisorba minor, Salix fragilis and Spergularia rubra type. The pollen of the systematic units, which had pollen loads that could be identified at the level of species, maintained a constant value of protein content independently of the date the samples were obtained. The pollen of the systematic units, which had pollen loads that could be identified at the level of pollen type, has varied in protein content in the analyses performed on samples obtained on different dates. This result is due to the fact that the different species that integrate the pollen type flower on different dates, and thus have a pollenkitt with different characteristics.

Analysis of pollen load based on color, physicochemical composition and botanical source

Pollen load samples from 10 hives of Apis mellifera (L.) were analyzed based on their physicochemical composition and botanical source, considering color as a parameter for quality control. In seven samples it was possible to establish the occurrence of more than 80% of a single pollen type, characterizing them as unifloral but with protein content variation. One of the samples was exclusively composed of saprophytic fungi (Cladosporium sp.). Comparing the mean results of the fungi loads with those of the nutritional components of pollen load, the former presented higher protein, mineral matter and dry matter and lower organic matter, ethereal extract and total carbohydrate values. The monochromatic samples met the physicochemical specifications regulating pollen load quality. The results showed that homogeneous coloration of the pollen load was not found to be a good indication of unifloral pollen, confirming the importance of physicochemical analysis and melissopalynological analysis for characterization of the quality of commercial pollen load.

Initial data on the specific heterogeneity found in the bee pollen loads produced in the Pontevedra region (north‐west Spain)

Heterogeneous pollen load frequency from a beehive located in the Morcón (Pontevedra, north‐west Spain) was recorded. Samples of pollen loads were obtained weekly between May and July using pollen traps, and the accumulated pollen was removed at different times. Of the total analysed pollen loads an average heterogeneity percentage of approximately 5% was recorded. The pollen load heterogeneity consisted of mixed pellets with pollen of several species, but usually with one species (Erica umbellata L., Lythrum salicaria L., Lotus corniculatus L., Cytisus scoparius‐type, Castanea sativa Miller, Echium plantagineum L., Reseda media Lag., Erica cinerea L., Trifolium arvense L., Lonicera peryclimenum L., Scandix pecten‐veneris L., Calystegia sepium (L.) Br., Crepis capillaris (L.) Wallr., Eucalyptus globulus Labill., Plantago lanceolata L., ‐Raphanus raphanistrum L., Rubus ulmifolius‐ type or Poaceae) having higher values than others. It appears that mixed loads are not the result of flower deception but related to a decrease in pollen availability from plants the bees are currently foraging on that result in mixed foraging behaviour on other taxa.

Recursos tróficos de Apis mellifera L. (Hymenoptera, Apidae) na região de Morro Azul do Tinguá, Estado do Rio de Janeiro

The original vegetation in the Morro Azul mountain region, northwest of Rio de Janeiro city, was the Atlantic tropical rain forest. Anthropic activities transformed the vegetation into pastureland and patches of the original forest. In addition, there are reforested areas of Pinus, Eucalyptus and others of non native plant species. The aim of the present research was to estimate the contribution of nectar and pollen from each type of vegetation for Apis mellifera bees, using pollen analysis. Eleven monthly collected honey samples and nine samples of pollen loads were obtained in a control-hive and prepared for pollen analysis following the standard European methodology without application of acetolysis. Six honey samples were considered monofloral, as of Baccharis (March), Gochnatia (April and November), Eucalyptus (September and October) and Castanea (August). Three were considered bifloral ones, as of Mimosa scabrella pollen type and Piptadenia (January), Eucalyptus and Eupatorium (June) and Phytolacca and Machaerium pollen type (October). Heterofloral honeys occurred in July (Arecaceae, Eucalyptus and Allophylus) and in December (Anadenanthera, Eupatorium and Eucalyptus). The dominant pollen loads comprised the pollen types of Arecaceae, Baccharis, Castanea, Cecropia, Eucalyptus and Mimosa caesalpiniifolia Benth. The results provided a pollen spectrum that reflected the nectariferous and polliniferous contribution of field vegetation and of introduced plant species in the study region.

Fatty acid composition and palynological analysis of bee (Apis) pollen loads in the states of São Paulo and Minas Gerais, Brazil

SUMMARYThe fatty-acid composition and botanical origin of 14 honey bee (Apis mellifera) pollen load samples acquired in shops and apiaries in Minas Gerais and São Paulo states, Brazil, were determined. The fatty acids presented a variable composition among these samples. All samples contained oleic, linoleic and arachidic acid. Only one sample did not contain palmitic acid. The unsaturated fatty-acid level varied from 18.6% to 55.9% of the total fatty-acid composition, suggesting that pollen is a good source of unsaturated fatty acids to the diet. Several pollen types were identified. Eucalyptus (Myrtaceae) and Eupatorium (Asteraceae) pollen types were the most common among those sampled. These data might help the regulatory agencies establish quality parameters for pollen produced in Brazil. There are no additional data available on Brazilian pollen fatty acid composition.

The Widespread Occurrence of Anther Destruction by Trigona Bees in Melastomataceae

The Widespread Occurrence of Anther Destruction by Trigona Bees in Melastomataceae