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Amino Acid Content of Dandelion Pollen, a Honey Bee (Hymenoptera: Apidae) Nutritional Evaluation
Abstract
Amino acid content of honey bee-collected (Apis mellifera L.) and hand-collected dandelion, Taraxacum officinale Weber ex Wigg., pollen was determined by ion exchange chromatography of acid-hydrolyzed samples. Hand-collected pollen (one source) was unexpectedly higher in proline and valine than bee-collected pollen (five sources). Generally, dandelion pollen was low relative to honey bee requirements in valine and isoleucine and low in leucine and arginine. The reported poor brood-rearing capability of dandelion pollen appears to be the result of multiamino acid deficiency.
... In 2016, all nine colonies were randomly divided into three treatment groups (N ¼ 3 colonies/treatment): (1) control, which had the pollen traps at the off position for the duration of the experiment, (2) a semi-synthetic diet with all 10/10 honey bee EAAs, representing a polyfloral diet (DeGroot, 1953), and (3) a semi-synthetic diet treatment with only 6/10 EAAs, representing the EAAs honey bees would receive from a monofloral dandelion diet (Auclair & Jamieson, 1948;Loper & Cohen, 1987) (Table 1). The semi-synthetic "dandelion" diet is ecologically relevant as dandelions are one of the few floral resources available to bees in early spring in the North-eastern United States (Loper & Cohen, 1987). ...
... In 2016, all nine colonies were randomly divided into three treatment groups (N ¼ 3 colonies/treatment): (1) control, which had the pollen traps at the off position for the duration of the experiment, (2) a semi-synthetic diet with all 10/10 honey bee EAAs, representing a polyfloral diet (DeGroot, 1953), and (3) a semi-synthetic diet treatment with only 6/10 EAAs, representing the EAAs honey bees would receive from a monofloral dandelion diet (Auclair & Jamieson, 1948;Loper & Cohen, 1987) (Table 1). The semi-synthetic "dandelion" diet is ecologically relevant as dandelions are one of the few floral resources available to bees in early spring in the North-eastern United States (Loper & Cohen, 1987). To control for hive location and allow for year-to-year comparison, the order of diet treatments at site A was kept the same in 2017 as 2016. ...
... Honey bee EAAs (DeGroot, 1953) Minimum % required by the honey bee (DeGroot, 1953) % in bee collected sunflower pollen (Nicolson & Human, 2013) % in bee collected almond pollen (Standifer et al., 1980 Note. Values in bold demonstrate EAA levels that are either missing completely or are not large enough to sustain a healthy honey bee brood development. a Amino acids in dandelion pollen (Auclair & Jamieson, 1948;Loper & Cohen, 1987). Table S1). ...
Commercial honey bee colonies pollinate large monocultures, which contain one type of food and thus, one unbalanced source of nutrients. We examined how a lack of dietary essential amino acids (EAAs) affects honey bee foraging behavior and colony growth. Using pollen traps and semi-synthetic diets, we raised bees on three treatments in the field: no diet manipulation, a diet with all 10/10 honey bee EAAs, or a diet with only 6/10 EAAs. In 2016, during a drought, bees raised on the diet lacking EAAs collected more pollen than bees raised with all EAAs, suggesting compensatory foraging. This was not found in 2017, when natural resources were likely more abundant. As such, honey bees lacking EAAs worked harder to fill the gap in the nutrient poor environment. In 2017, colonies raised on all 10 EAAs expanded slower than control colonies, and colonies raised on 6/10 EAAs did not expand at all. This suggests that EAA diversity, and likely other nutrients found in pollen, are essential for colony growth. Forcing this generalist pollinator to be a specialist drastically reduces colony growth and likely, honey bee fitness.
... Segundo Liolios et al. (2016), tal ocorrência se justifica porque as abelhas coletam pólen de um grande número de plantas, mas apenas alguns contribuem significativamente para suas necessidades proteicas. No entanto, algumas pesquisas apontam que a composição de aminoácidos pode determinar o valor nutricional do pólen com mais exatidão que o teor de proteínas, uma vez que esse nutriente é reduzido na ausência de aminoácidos essenciais (MCCAUGHEY et al., 1980;LOPER;COHEN, 1987;COOK et al., 2003). Durante o período chuvoso os voos externos às colônias são dedicados, basicamente, à recolha de lixo, coleta de água e resina para o controle térmico e impermeabilização da colônia, uma vez que, na época chuvosa, as temperaturas podem ser mais altas (NEWSTROM et al., 1994;OLIVEIRA et al., 2012;SOUZA et al., 2014). ...
... Segundo Liolios et al. (2016), tal ocorrência se justifica porque as abelhas coletam pólen de um grande número de plantas, mas apenas alguns contribuem significativamente para suas necessidades proteicas. No entanto, algumas pesquisas apontam que a composição de aminoácidos pode determinar o valor nutricional do pólen com mais exatidão que o teor de proteínas, uma vez que esse nutriente é reduzido na ausência de aminoácidos essenciais (MCCAUGHEY et al., 1980;LOPER;COHEN, 1987;COOK et al., 2003). Durante o período chuvoso os voos externos às colônias são dedicados, basicamente, à recolha de lixo, coleta de água e resina para o controle térmico e impermeabilização da colônia, uma vez que, na época chuvosa, as temperaturas podem ser mais altas (NEWSTROM et al., 1994;OLIVEIRA et al., 2012;SOUZA et al., 2014). ...
Within the amazon region 130 species of stingless bees can be found, grouped into 26 genera, where Melipona and Trigona are the most represented. In Acre there is official record of 20 genera and 64 species of stingless bees, among those M. eburnea is one of the members, being very common in the Acre forests and rationally created by melipolinculturists, in the municipality of Rio Branco. The objectives that integrated this job were: (i) to identify botanical species used by M. eburnea to collect pollen and nectar; (ii) to determine the frequency of pollen types found in honey itself as well as in the pollen charges of the bees´ corbicles of M. eburnea; (iii) to point out the flowering seasonality of the plants used by M. eburnea to collect pollen and nectar; (iv) to identify the growth habits of M. eburnea´ s pollen and nectar suppliers; (v) to indicate the contribution of native, cultivated and ruderal species in the supply of pollen and nectar to M. eburnea; (vi) to verify the influence of rainfall and light intensity on the supply of food resources for M. eburnea, throughout the year; (vii) to assess the protein content and the specific concentration of amino acids content in the pollen collected by M. eburnea, throughout the year and (viii) to check if there is a link between the different levels of protein and amino acids with the diversity of pollen types collected by M. eburnea. Once a week, from April 2017 to March 2019, from 5 am to 9 am. worker bees from three colonies of M. eburnea have been sampled. The weekly samples have been gathered, thus creating a single monthly sample. The pollen sources used by M. eburnea have consequently been determined by sampling the pollen loads from the worker bees, when returning to the colony with pollen in their corbicles. The sources of nectar have been confirmed by checking on honey samples taken from the pots, still open. In order to quantify the protein content and the amino acid profile, the samples have been collected together with those of pollen and honey, in still open pollen pots and from the same selected colonies. After that, pollen has been collected and sampled from plants present in the study area, as well as from the dried ones, kept in the UFAC – UFACPZ herbarium, to preparing a reference “pollen library”. Microscopy slides have been set to perform qualitative and quantitative analysis of the pollen types contained in the samples of the bees´ charges, honey and pollen pots. Palynological analysis have shown that M. eburnea bees have harvested floral resources from 115 botanical species, belonging to 47 families and 96 genera: 61 species have been used both to collect pollen and nectar, 19 only for pollen collection and 35 just for nectar extraction. Fabaceae (Mimosoideae) and Myrtaceae
have been the main sources of pollen and nectar to M. eburnea, in all the seasons of the bee calendar (rainy, rain-dry transition, drought and dry-rain transition). Among the pollen types of the corbicle loads´ samples, Mimosa pudica represented the highest concentration 6.79 (log 10). When considering the volume of the pollen grain, Hybiscus was the most important. Among those classified in the honey samples, Crotalaria retusa obtained the highest concentration of 6.56 (log 10). In the main group of plants visited by M. eburnea, 50.61% were native; 36.59% cultivated and 12.81% ruderal. Referring to the habit, 40.25% were trees; 34.59% bushes; 13.21% herbs; 8.18% vines; 3.14% sub-shrubs and 0.63% epiphytes. The seasonality of the botanical species utilized by M. eburnea to collect floral resources has demonstrated wide variation throughout the study period: the pollen types Solanum and M. pudica have turned out being the least seasonal, in the corbicula loads´ samples. Among honey ones, Combretum. These pollen types have been present during the all assessed months. 13 amino acids have been found in the pollen stored by M. eburnea, nine of which are essential ones. In this group, Arginine was preponderant. Among the non-essentials, Proline has shown the highest concentration, being predominant in the set of identified amino acids as well, representing 68.5%. The levels of raw protein vary from 16.57 to 24.39%, within an average of 20.75%. The highest concentration of flowering has occurred in the dry season, characterized by a decrease in the volume of rainfalls and an increase in the amount of hours of sunshine. As for the totality of plants visited by M. eburnea, 38.39% offered pollen and/or nectar, during the dry season. It is concluded that (i) M. eburnea presents a generalist behavior in the use of pollen sources; (ii) the main sources of pollen and nectar for M. eburnea have been Fabaceae and Myrtaceae; (iii) native vegetation, mainly trees and bushes, have been the primary source of pollen and nectar for M. eburnea; (iv) an association among native, cultivated and ruderal plants provides appropriate amounts of proteins and amino acids for M. eburnea.
Keywords: Stingless bee, Rational breeding, Meliponiculture, Floral resources, Agroforestry system – AFS.
... Segundo Liolios et al. (2016), tal ocorrência se justifica porque as abelhas coletam pólen de um grande número de plantas, mas apenas alguns contribuem significativamente para suas necessidades proteicas. No entanto, algumas pesquisas apontam que a composição de aminoácidos pode determinar o valor nutricional do pólen com mais exatidão que o teor de proteínas, uma vez que esse nutriente é reduzido na ausência de aminoácidos essenciais (MCCAUGHEY et al., 1980;LOPER;COHEN, 1987;COOK et al., 2003). Durante o período chuvoso os voos externos às colônias são dedicados, basicamente, à recolha de lixo, coleta de água e resina para o controle térmico e impermeabilização da colônia, uma vez que, na época chuvosa, as temperaturas podem ser mais altas (NEWSTROM et al., 1994;OLIVEIRA et al., 2012;SOUZA et al., 2014). ...
... Segundo Liolios et al. (2016), tal ocorrência se justifica porque as abelhas coletam pólen de um grande número de plantas, mas apenas alguns contribuem significativamente para suas necessidades proteicas. No entanto, algumas pesquisas apontam que a composição de aminoácidos pode determinar o valor nutricional do pólen com mais exatidão que o teor de proteínas, uma vez que esse nutriente é reduzido na ausência de aminoácidos essenciais (MCCAUGHEY et al., 1980;LOPER;COHEN, 1987;COOK et al., 2003). Durante o período chuvoso os voos externos às colônias são dedicados, basicamente, à recolha de lixo, coleta de água e resina para o controle térmico e impermeabilização da colônia, uma vez que, na época chuvosa, as temperaturas podem ser mais altas (NEWSTROM et al., 1994;OLIVEIRA et al., 2012;SOUZA et al., 2014). ...
... The two dandelion species, Taraxacum officinale and Taraxacum erythrospermum, are the most commonly found wild flowers worldwide. They have a long history of being used as medicinal herbs, and have been used as food coloring with the US Food and Drug Administration approving dandelion extracts as "Generally Recognized as Safe" [20][21][22][23][24] . Motivated by these precedents, we decided to investigate the extraction and loading of dandelion SECs. ...
... Considering that proteins are the only major component of pollen cytoplasm that contain nitrogen 4 , CHN element analysis was performed to further verify the protein degradation. Results of CHN analysis indicate that defatted dandelion contains ~12.88 wt% of proteins (Fig. 7), in agreement with the previous literature 22 . Meanwhile, acidolysis with phosphoric acid resulted in the largest overall reduction in protein, to less than 6%, even after only 2.5 h of treatment. ...
Pollen-based microcapsules such as hollow sporopollenin exine capsules (SECs) have emerged as excellent drug delivery and microencapsulation vehicles. To date, SECs have been extracted primarily from a wide range of natural pollen species possessing largely spherical geometries and uniform surface features. Nonetheless, exploring pollen species with more diverse architectural features could lead to new application possibilities. One promising class of candidates is dandelion pollen grains, which possess architecturally intricate, cage-like microstructures composed of robust sporopollenin biopolymers. Here, we report the successful extraction and macromolecular loading of dandelion SECs. Preservation of SEC morphology and successful removal of proteinaceous materials was evaluated using scanning electron microscopy (SEM), matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, elemental CHN analysis, dynamic image particle analysis (DIPA) and confocal laser scanning microscopy (CLSM). Among the tested processing schemes, acidolysis using 85% (v/v) phosphoric acid refluxed at 70 °C for 5 hours yielded an optimal balance of intact particle yield, protein removal, and preservation of cage-like microstructure. For proof-of-concept loading, bovine serum albumin (BSA) was encapsulated within the dandelion SECs with high efficiency (32.23 ± 0.33%). Overall, our findings highlight how hollow microcapsules with diverse architectural features can be readily prepared and utilized from plant-based materials.
... We explore the consequences of alternative sampling intensities for surveys of floral abundance and develop predictive statistical models for pollen volume per flower (based on floral morphology) and nectar and pollen resource per unit area (based on flower counts). Our approach does not incorporate variation in resource quality [52][53][54], but can easily be modified to do so where suitable data exist (see Discussion). ...
... For example, Taraxacum spp. pollens lack the amino acids cysteine, tryptophan and phenylalanine and have low levels of valine, methionine, and isoleucine [52,53]. This is associated with demonstrated low nutritional value of Taraxacum pollen to some social bees [88,92]. ...
Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many 'pollinator-friendly' seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial) and associated weeds grown as 300m 2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg.) contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated PLOS ONE |
... Alnus pollen is of poor quality for brood rearing and Picea has a very poor protein content (Ramsay 1987). In addition, according to Loper and Cohen (1987) , dandelion pollen is low in tryptophan, phenylalanine, and arginine and does not foster brood rearing. Finally, the third most important pollen collected by the honey bees whose hives were placed in blueberry monocultures was from the lowbush blueberry itself, V. angustifolium. ...
... Salix spp., Rubus spp., and Brassicaceae pollen have an excellent protein quality and content (very poor protein content = 10% vs. excellent = 30% according to Ramsay 1987), thus allowing normal brood rearing in colonies placed in the mixed and non-Vaccinium field site categories. In July, the colonies in each site category had access to a better quality of pollen in terms of protein percentage and amino acid content, with plants such as the Brassicaceae, Trifolium spp., V. macrocarpon, Oenothera biennis L., and Rubus type (Loper and Cohen 1987; Ramsay 1987). This may explain why colonies that had suffered brood rearing problems in blueberry monocultures recovered and started rearing broods as fast as the colonies introduced in the mixed sites for the cranberry flowering period. ...
Access to a rich diversity of flowering plants is very important for the development of honey bee colonies introduced in crops for pollination. The aim of this observational study was to determine the impact of surrounding pollen diversity on the health of honey bee colonies introduced in lowbush blueberries (Vaccinium angustifolium Ait.) in June and cranberries (Vaccinium macrocarpon Ait.) in July. The results suggest that monocultures of lowbush blueberries are not suitable for optimal brood rearing. In the blueberry environments we studied, the dominant pollen collected by honey bees were Alnus Mill. spp. and Taraxacum officinale F.H. Wigg., which are deficient in some essential amino acids. Significant reduction of brood rearing during honey bees’ stay in blueberry monocultures in June may, therefore, be explained by nutritional deficiencies. In July, the polliniferous flora in the vicinity of cranberry monocultures was poorer but of better nutritional quality. Pollen analysis allowed the identification of Brassicaceae, Trifolium L. spp., and V. macrocarpon as the three dominant taxa collected by honey bees during this period. The complete lists of plant taxa foraged by honey bees for pollen during the pollination of lowbush blueberries and cranberries are provided.
... Navarrete et al. (2016) destaca los géneros Crepis e Hypochoeris en análisis polínico y fitoquímico de mieles del Biobío, sin embargo, no hay referencias de importancia de asteráceas de la Patagonia. El Taraxacum no sería importante para la alimentación de las abejas (Loper & Cohen, 1987) debido a la pobre capacidad de crianza reportada del polen de diente de león, lo que parece ser el resultado de una deficiencia de multi aminoácidos. ...
El rubro apícola de Chile lo constituyen cerca de 11.583 personas y 1.533.405 colmenas, que generan diferentes productos como; miel, cera, jalea real, polen, propóleos y servicios de polinización, siendo la miel el producto de mayor importancia por su cantidad y aporte económico. Hoy en día existe una positiva apreciación y valoración de los beneficios de la apicultura para la agricultura familia campesina (AFC). Para que la actividad productiva sea provechosa es necesario conjugar factores como; las competencias y conocimientos técnicos de los apicultores (capacitación), la capacidad productiva de las familias de abejas (genética) y el medio ambiente físico donde estén insertas las colmenas (oferta floral). Conocer las especies vegetales con propiedades melíferas reviste un importante desafío para profesionales del área forestal que trabajan asesorando a los apicultores, como ejemplo, solo en la anterior temporada la producción de miel originada del bosque nativo fue exportada en un 90% a mercados de la Unión Europea y EEUU, constituyéndose en el principal producto pecuario primario exportado por Chile. En la región de Aysén la actividad apícola es una actividad económica emergente, constituida por 142 apicultores y 2.137 colmenas. Los conocimientos en flora apícola son escasos, por ello, el presente trabajo busca generar conocimiento sobre las principales especies vegetales de uso apícola presentes en las diferentes ecorregiones de Aysén.
... Both adult and larval bees highly depended on diets containing sufficient levels of methionine (Szczesna 2006;Michener 2007). Moreover, honey bees are unable to rear broods when the food is deficient in methionine (Loper and Cohen 1987). The significant influence of methionine in nectar on bees' flower preference in our study meadow infers the importance of methionine for bees. ...
Trait-based analyses that elaborate the biological mechanisms underlying species interactions are crucial for predicting the structure of community plants and animals. Flower nectar, a sugar-rich solution, is fundamental to linking flowers and animal visitors for most plants. However, there is a paucity of knowledge regarding the influence of nectar micro-components, such as amino acids (AAs), and their relative composition on foraging decisions of flower visitors within a community context.
We quantitatively calculated the relative composition of 21 AAs of nectars from 40 species and recorded the visitation frequency of their 207 species of insect visitors (15 functional groups from five orders) in a species-rich alpine meadow. Phylogenetically generalized mixed models with Bayesian estimation were used to detect the influence of nectar AAs on the visitation frequency of flower visitors from the different groups.
Our results indicated that the increase of γ-aminobutyric acid (GABA) and methionine in nectar enhanced the visitation of social bees, the dominant flower visitors in this meadow. Furthermore, the AAs in nectar that affect visitation frequency varied among different functional groups of Dipteran, e.g., hoverfly, mucoid fly, meat fly, and horsefly. Their different diet sources and life history strategies (e.g., feeding larvae or not) may explain the preferring or disliking of nectar AAs.
Our findings suggest a way that flower reward may structure plant-pollinator interactions in communities with diverse species, which enriches the understanding of mechanisms for biodiversity maintenance.
... Vanderplanck et al. (2020) argued that chemical properties of Taraxacum pollen, such as the presence of toxic compounds or nutrient deficits, were the most likely explanation for the noxious effects of this pollen on bees; and the finding that Taraxacum pollen can have allelopathic effects on neighbouring plants (Loughnan et al. 2014) supports the hypothesis that it contains toxins. The nutritional composition of Taraxacum pollen also appears unusual (low in P, K and Fe) even compared to other Asteraceae (Filipiak 2019), and it may be deficient in certain essential amino acids (Auclair andJamieson 1948, Loper andCohen 1987). For example, on a diet consisting only of Taraxacum pollen, young honeybees failed to rear brood (Herbert et al. 1970), and adults died sooner (Knox et al. 1971) than those reared on other pollen diets. ...
Organisms inhabiting seasonal environments must fit their life cycle into a limited time window while also synchronizing periods of resource consumption with timing of resource availability. Introduced non‐native species, which often differ in phenology from natives, can alter and expand the seasonal window of resource availability for native consumers, providing potential fitness benefits. However, if these non‐native resources are nutritionally unsuitable for native consumers, their presence could elicit foraging behaviour that proves maladaptive – i.e. they could act as an ecological trap. Here, we used multi‐year field observations and a laboratory experiment to investigate the impacts of a common non‐native plant species on two components of fitness in three solitary bee species (all specialist consumers of pollen from the plant family Asteraceae) native to the Colorado Rocky Mountains. First, we tested whether individual bees that collect pollen from the non‐native common dandelion Taraxacum officinale produce more offspring than those that do not, thanks to the unusually early flowering phenology of the non‐native. Second, we compared survival of bee larvae experimentally reared on Taraxacum pollen to that of larvae reared on native Asteraceae pollen. Bees that used at least some non‐native Taraxacum pollen produced more potentially viable offspring, but larval survival was significantly reduced for bee larvae experimentally fed provisions dominated by Taraxacum pollen. Therefore, survival costs may negate the potential fitness benefits of early nesting, indicating that non‐native floral resource use may act as an ecological trap for native bees. Using a series of simple simulations informed by our results, we explore the fitness effects of non‐native floral resource use, demonstrating that the net cost or benefit depends on how bees respond to resource shortages. Our results highlight the importance of considering organisms' full life cycles when evaluating the fitness consequences of resource availability and species introductions.
... As reported by Rebelo [26], the CP content in Melipona seminigra was 37.63%, and in Melipona interrupta, it was 24%, in Melipona subnitida, it was 27.02%, and in Melipona scutellaris, the reported value was 20.81% [27], demonstrating significant variation among species of the genus Melipona. In addition to the CP content, other factors, such as amino acid composition, are critical in determining the nutritional quality of pollen, as they provide a more precise indicator of its nutritional value [32,33]. ...
Stingless bees are vital pollinators in tropical and neotropical regions, emphasizing the need to conserve these species. However, resource scarcity, particularly pollen, during certain periods negatively impacts bee health and pollination efficiency. To address this, we developed a fermented protein feed using microorganisms from pollen of Melipona quadrifasciata, a species commonly found in the Brazilian Atlantic Forest. The fermented feed consisted of a protein bran mixture, sugar syrup, and an inoculant derived from species’ fermented pollen. To assess the feed quality, nutritional evaluation and metabolomic analyses were conducted (UHPLC/DAD-HRMS/MS and GC-MS). The metabolomic analysis identified 85 compounds in positive and 102 in negative ionization modes. Shared metabolites, such as isoquercetin and palatinose, highlighted similarities between the feed and natural fermented pollen. Laboratory tests with caged bees showed comparable consumption between the feed and fermented pollen with no statistical difference (mean: 0.067 g vs. 0.060 g; p = 0.53). The feed exhibited a favorable pH transition (5.30 pre-fermentation to 4.41 after the fermentation process) and remained stable for six months at ±2 °C. These findings demonstrate a biotechnological advance in stingless bee nutrition, offering a viable solution during resource scarcity and promoting the health of M. quadrifasciata.
... Amino acid profiles were analyzed using official AOAC 994.12 methodologies for livestock feed analysis. For purposes of comparing the relative protein quality of LX3 fermented patties, essential amino acid composition for beebread (a mixture of pollen with nectar or organic honey) and 16 common pollen sources were derived from previous reports [36][37][38]. Principal component analysis (PCA) was performed using the prcomp function in R (v3.6.0) with amino acid concentrations (g/16g N) used as input values and data scaled to be zero centered using the center = TRUE option. ...
Managed honey bee ( Apis mellifera ) populations play a crucial role in supporting pollination of food crops but are facing unsustainable colony losses, largely due to rampant disease spread within agricultural environments. While mounting evidence suggests that select lactobacilli strains (some being natural symbionts of honey bees) can protect against multiple infections, there has been limited validation at the field-level and few methods exist for applying viable microorganisms to the hive. Here, we compare how two different delivery systems—standard pollen patty infusion and a novel spray-based formulation—affect supplementation of a three-strain lactobacilli consortium (LX3). Hives in a pathogen-dense region of California are supplemented for 4 weeks and then monitored over a 20-week period for health outcomes. Results show both delivery methods facilitate viable uptake of LX3 in adult bees, although the strains do not colonize long-term. Despite this, LX3 treatments induce transcriptional immune responses leading to sustained decreases in many opportunistic bacterial and fungal pathogens, as well as selective enrichment of core symbionts including Bombilactobacillus , Bifidobacterium , Lactobacillus , and Bartonella spp. These changes are ultimately associated with greater brood production and colony growth relative to vehicle controls, and with no apparent trade-offs in ectoparasitic Varroa mite burdens. Furthermore, spray-LX3 exerts potent activities against Ascosphaera apis (a deadly brood pathogen) likely stemming from in-hive dispersal differences, whereas patty-LX3 promotes synergistic brood development via unique nutritional benefits. These findings provide a foundational basis for spray-based probiotic application in apiculture and collectively highlight the importance of considering delivery method in disease management strategies.
... However, the relationship based on the major nutrients and their proportions and the nine parameters in the pollen shows that pollen with a higher essential amino acid content has advantages in the initial egg-laying time, the number of eggs laid, time of first worker emergence, and the average weight of workers in the first batch, while a higher protein content can only accelerate the colony development. Although high-protein pollens generally contribute more to colony growth and development than low-protein pollens [58,59], the nutritional quality of high-protein pollen is reduced if there are inadequate amounts of the essential amino acids required for growth [58,60]. Therefore, the composition and content of amino acids can be used to more accurately evaluate the nutritional value of pollen than the content of protein [61,62]. ...
Simple Summary
Bombus breviceps is an important native species of bumblebee in southern China. As a pollinator, it has the potential for domestication and commercial rearing. In this study, in order to identify the nutritional requirements for the egg-laying, hatching, and colony foundation stages, we selected three common local types of pollen, including camellia pollen, oilseed rape pollen, and apricot pollen, as well as mixtures of them, to feed B. breviceps queens to evaluate the reproductive performance, and feasibility of these pollens as a diet and the nutritional requirements. The results showed that the pollen with a higher essential amino acid content had advantages in laying time, the number of eggs laid, larval ejection, and the time of first worker emergence, while the pollen with a higher crude protein content had advantages in the time the colony took to reach ten workers. These results may guide the selection of feed in B. breviceps artificial feeding and help to explore the nutritional requirements in oviposition and the colony stage from the perspective of conventional pollen.
Abstract
Pollen is an important source of nutrition for bumblebees to survive, reproduce, and raise their offspring. To explore the nutritional requirements for the egg laying and hatching of queenright Bombus breviceps colonies, camellia pollen, oilseed rape pollen, apricot pollen, and mixtures of two or three types of pollen in equal proportions were used to feed the queens in this study. The results showed that the camellia pollen with a higher essential amino acid content was superior to the pollen with a lower essential amino acid content in the initial egg-laying time (p < 0.05), egg number (p < 0.05), larval ejection (p < 0.01), time of first worker emergence (p < 0.05), and the average weight of workers in the first batch (p < 0.01). It took less time for colonies under the camellia pollen and camellia–oilseed rape–apricot pollen mix treatments, both with a higher crude protein content, to reach ten workers in the colony (p < 0.01). On the contrary, the queens fed apricot pollen never laid an egg, and larvae fed oilseed rape pollen were all ejected—both pollens with a lower essential amino acid content. The results emphasize that the diet should be rationally allocated to meet the nutritional needs of local bumblebees at various stages when guiding them to lay eggs, hatch, and develop a colony.
... Moreover, the mean survival rate was positively related to the mean amount of protein consumed per bee and negatively related to the amount of Asteraceae in the mixture (Frias et al., 2016). This was thought to be due to two reasons: firstly protein levels of Asteraceae are usually low compared to other familial pollen types ; secondly, Asteraceae (sunflower and dandelion) have also been shown to lack essential amino acids (Loper and Cohen, 1987;Nicolson and Human, 2013), as well leading to low rates of digestion in honey bees (Peng et al., 1985;. ...
The European honey, Apis Melifera L., is the most commonly managed bee in the world, but despite an increase in the global stocks of honey bees, areas such as Europe (-26.5%) and North America (-49.5%) have experienced notable declines at the colony level. Although less data is available on the position of honey bees in the tropics, what is available suggests that there is a deficit of 210,00 honey bee hives compared to global trends. These declines are driven by a number of synergistic stressors, including land use change, pesticide exposure, as well as pathogen and parasite infection. This thesis investigates how in a tropical environment, Belize, the Africanised honey bee is impacted by the landscape, and in particular their subsequent diet and exposure to pesticides. Apiculture is one of the most widespread agricultural activities practised globally, with an estimated 94 million honey bee colonies present worldwide in 2020. Beekeeping offers substantial benefits to local people, particularly in rural developing communities, where it provides economic opportunities, through the production of honey, wax and bee bread. In addition, the impact of landscape on honey bee learning in the UK was also analysed, and for the first time directly compares visual learning across a gradient of landscapes, contributing to the growing knowledge of bee behaviour and cognition. Analysis of the honey bee pollen diet across the Toledo and Cayo districts of Belize was carried out by identifying the pollen grains in bee bread samples. The most abundant and frequently occurring taxa were identified and community compositions studied. Tree species were found to be of particular importance, making up 80% of the 10 most relatively abundant species. This study contributes to the growing body of research highlighting the importance of trees in bee diets. No relationship was found between the most abundant pollen taxa and their nutritional make up based on crude protein levels, suggesting that the abundance of the pollen in the environment is more likely the driver behind its dominance in the bee bread. The effects of landscape diversity on species richness, species diversity and community compositions of pollen found in bee bread was compared in the Toledo and Cayo districts. A negative relationship was found between landscape diversity and both pollen richness and diversity. This may be due to the complex relationship between each plant/pollen taxa and the landscape, as well as bee preference. A high abundance of preferred species within the landscape acts to lower the diversity and richness of pollen with the honey bees diet. This data suggests that the presence and dominance of preferred species in the landscape is more important than landscape diversity when it comes to determining honey bee diet. The presence of pesticides in bee bread samples from honey bee hives located across a gradient off natural and agricultural landscapes was also investigated. Pesticides were not found in any of the samples, suggesting that exposure of honey bees to pesticides via their pollen diet does not represent a risk in Belize. The lack of pollen contamination of pesticides is likely due to the bees preference of tree pollen which does not receive pesticide treatment, and is unlikely to experience accidental treatment due to the main application methods in Belize, knapsack spraying. Finally, the effects of landscape complexity and composition on honey bee cognition was studied directly in the field. Visual learning, a crucial component of bee behaviour used to find food resources, was compared across a gradient of landscapes with a range of complexity, whilst compositional changes were kept to a minimum. To do this a field adapted version of the proboscis extension response was utilised, and bees were taught to associate different coloured paper strips with positive and negative rewards. Results showed that as landscape edge density increased bee learning reduced, and while landscape diversity increased so did bee learning. This is important as to ensure colony survival, bees must learn foraging routes, find profitable flowers, develop spatial maps as well as recognise intruders. Landscape has been shown to be an influential factor in both determining the pollen diet of bees as well as their learning ability, but in Belize did not contribute to pesticide exposure through their pollen diet, likely due to the pesticide application methods and bee preference for tree species. When placing bee hives in both Belize and the UK, it is therefore important to consider there placement in terms of landscape, to increase the likelihood of developing a strong and successful colony.
... Dandelion is one of the most common weeds in urban areas of England (Ollerton 2021). Whilst the species does produce a lot of nectar which is used by bees, the pollen from dandelion flowers is considered low in nutrition and bees have difficulty rearing brood on pure dandelion pollen (Herbert et al. 1987;Loper and Cohen 1987). Although dandelion was the second most abundant urban plant, it was much less abundant in the nature areas, but still an important component of the network. ...
Biodiversity is declining through human activities and urbanisation is often seen as a particular concern. Urban settings, however, provide diverse microclimatic conditions for plants and pollinating insects, and therefore may be significant habitats for the conservation of solitary and primitively eusocial bees, a major group of pollinators. This study analysed the interactions between these bees and the plants on which they forage, using a network approach. We compared urban habitats (gardens, roadsides, and open vegetation) in a large British town with nearby nature reserves. One native plant Taraxacum officinale (dandelion) was a core generalist species visited in all habitat types. Other core plant species restricted to particular habitats include species of Geranium, Bellis, Crepis, and Ranunculus. Two generalist bee species, Anthophora plumipes and Osmia bicornis were the core visitor species within the networks. The networks were comparatively more nested in urban habitat types than nature areas, suggesting more frequent interactions between generalist and specialist species in urban areas. Network connectance, network level specialisation (H2’ index), and plant generality (network level) were not significantly different in urban and nature areas. However, visitor generality was found to be significantly higher in urban gardens than in nature areas. Careful management of common urban vegetation would be beneficial for supporting urban wild pollinators.
... Therefore, it is necessary to study the essential amino acids or micronutrients of avocado pollen. The nutritional quality of a pollen rich in proteins decreases if there are inadequate amounts of essential amino acids (McCaughey et al. 1980;Loper and Cohen 1987). Controlled density of nutrients stored in individuals, as well as the abdomen volume, did not show significant differences among treatments. ...
Nutritional stress is the major factor contributing to decline in the honey bee (Apis mellifera L.) populations given the high degree of dependence on floral resources, and due to the habitat loss. In this sense, monocultures of maize and avocado have great extensions in Mexico, but their impact on the physiology and morphology of A. mellifera is unknown. This research evaluated the effect of total protein content in monofloral (maize or avocado pollen diets) and polyfloral (using five types of pollen: Persea americana Mill., Zea mays L., Melampodium perfoliatum Cav., Drymaria villosa Cham Schltdl., and Lopezia racemosa Cav.) on their survival, body condition (controlled density, head mass, and development of hypopharyngeal glands; protein content in hemolymph), and immune response [lytic activity and activity of prophenoloxidase in the hemolymph (proPO)]. Corbicular pollen of P. americana had the highest protein content, followed by the corbicular pollen of Z. mays, M. perfoliatum, D. villosa, and L. racemosa. Polyfloral diet seems to be better for A. mellifera than the monofloral maize and avocado. Bees fed polyfloral pollen diet showed a high content of protein in the hemolymph in comparison with that fed maize or avocado pollen diets. Bees fed polyfloral and avocado pollen diet had the highest lytic activity but showed a decrease in proPO activity. In conclusion, polyfloral diets seem to be better for A. mellifera than the monofloral maize and avocado.
... Unfortunately, the pollen produced by many flowering plants are deficient in one or more essential amino acids [106][107][108]. Consequently, colonies kept on limited pollen sources may be susceptible to disease (particularly fungal infection by Nosema), produce little or no brood, and may completely perish [83,109,110]. The non-protein component of pollen (e.g., lipids, vitamins, and minerals) is also considered important, but its role is not well understood (reviewed by [20,43,78,[111][112][113]). ...
Habitat loss has reduced the available resources for apiarists and is a key driver of poor colony health, colony loss, and reduced honey yields. The biggest challenge for apiarists in the future will be meeting increasing demands for pollination services, honey, and other bee products with limited resources. Targeted landscape restoration focusing on high-value or high-yielding forage could ensure adequate floral resources are available to sustain the growing industry. Tools are currently needed to evaluate the likely productivity of potential sites for restoration and inform decisions about plant selections and arrangements and hive stocking rates, movements, and placements. We propose a new approach for designing sites for apiculture, centred on a model of honey production that predicts how changes to plant and hive decisions affect the resource supply, potential for bees to collect resources, consumption of resources by the colonies, and subsequently, amount of honey that may be produced. The proposed model is discussed with reference to existing models, and data input requirements are discussed with reference to an Australian case study area. We conclude that no existing model exactly meets the requirements of our proposed approach, but components of several existing models could be combined to achieve these needs.
... Pollen varies in terms of availability and concentration of necessary amino acids among plant species, but BEEHAVE neglects such differences in pollen qualities. Dandelion, for example, is important for honey bees in early spring and during times of dearth, but its pollen is lacking in some necessary amino acids resulting in lowered brood rearing success when honey bees rely on dandelion alone (Loper and Cohen 1987). If dandelion (infesting rye-grass pasture) is the only forage resource in spring, the scope of the model to capture all effects of this reduced pollen quality on brood rearing is limited, which might have led to an overestimation of honey bee colony performance. ...
Forage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in‐hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g., brood mortality). To assess overall colony viability, we developed metrics, PH and PP, which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four‐crop species systems composed of cereals, oilseed rape, maize, and sunflower, PH and PP were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in‐hive work force, which critically reduced colony resilience. Four‐crop systems composed of rye‐grass–dandelion pasture, trefoil–grass pasture, sunflower, and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 yr, and PH (269.5 kg) and PP (108 kg) being above viability thresholds for 5 yr. Overall, trefoil–grass pasture, oilseed rape, buckwheat, and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land‐use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.
... Managed honey bees, like all pollinators, have nutritional requirements that must be met by their surroundings in the form of pollen and nectar from flowers. As the sole source of protein for the colony, pollen is essential for normal physiological development and brood production [8][9][10]. Without sufficient pollen stores, the colony will decline in population [11][12][13]. ...
A present goal of the Conservation Reserve Program (CRP) is to manage land in agricultural landscapes to increase pollinator abundance and diversity. CP42, or the pollinator seed mix, is planted and managed to support foraging pollinators with blooming flowers present at all points in the foraging season. This high-quality habitat provides an excellent opportunity to study honey bee nutrition and determine whether honey bees located near CRP sites use known resources included in planting seed mixes. This study aims to highlight the primary sources of honey bee forage in the northern Midwest as well as to assess honey bee utilization of the floral resources provided by the pollinator seed mix used for CRP plantings. We received pollen samples collected using pollen traps by beekeepers in Ohio, South Dakota, Indiana, Illinois, and Michigan. Metabarcoding methods were used to identify and quantify pollen collected at different points in the season. The results indicate that honey bees frequently used major mass flowering resources such as Glycine, Trifolium, and Symphiotrichum throughout the season. In addition, flowers included in the CRP pollinator seed mix were used modestly. These results have implications for pollinator seed mix design.
... For example, dandelion pollen (Taraxacum campylodes G.E. Haglund), has a protein content that ranges from 9.2 to 19.2% of its dry weight, depending on the authors, its main lipids are made up linoleic and palmitic acid, and its mineral element composition is known as well. We also know that it is deficient in arginine and is missing essential amino acids such as tryptophane and phenol-alanine (Loper & Cohen, 1987). A few other complete data exists on pollen of gymnosperms and corn Zea mays L., but generally such complete data sets are rare and does not allow a multi-criteria classification of pollen types. ...
Ecosystems can be considered as dynamic and interactive clusters made up of plants, animals and microorganism communities. Inevitably, mankind is an integral part of each ecosystem and as such enjoys all its provided benefits. Driven by the increasing necessity to preserve the ecosystem productivity, several ecological studies have been conducted in the last few years, highlighting the current state in which our planet is, and focusing on future perspectives. This book contains comprehensive overviews and original studies focused on hazard analysis and evaluation of ecological variables affecting species diversity, richness and distribution, in order to identify the best management strategies to face and solve the conservation problems.
... EAA can be deficient in bee-collected pollen: for example, arginine in dandelion (Herbert et al., 1970) and histidine in corn (Höcherl et al., 2012). Multi-EAA deficiencies may occur, as was noted for eucalyptus pollen (Manning, 2001), which could result in poor colony brood production (Loper and Cohen, 1987). How active nutrient supplementation by foragers may meet colony needs is a focus of current research and debate (Bonoan et al., 2018;Corby-Harris et al., 2018;Lihoreau et al., 2018). ...
... In an assessment of western Palaearctic Colletes (Colletidae), Müller & Kuhlmann (2008) found that, although there was a wide variation in pollen specialization within the genus from pollen specialists to pollen generalists, Colletes species either specialized on Asteraceae pollen or avoided it almost entirely, with the authors dubbing this phenomenon 'the Asteraceae paradox'. Asteraceae pollen is known to be deficient in several amino acids important to bees (Loper & Cohen, 1987;Praz et al., 2008), and the chemical content of the pollenkitt (the lipid-rich coating found on each pollen grain) may interfere with the nutrient assimilation process, rendering its digestion difficult (Williams, 2003). If an investment in some kind of physiological adaptation is necessary to use a particular resource, we may expect a trade-off with a reduced ability to use alternative host plants (Scriber, 2005;Rasmann & Agrawal, 2011). ...
Andrena is a large genus of bees primarily distributed across the Holarctic. Despite their abundance in temperate regions, the pollen diets of many Nearctic Andrena remain incompletely resolved. The pollen diets of 50 species of Andrena found in Michigan were characterized using light microscopy. Twenty-four species (48%) were classified as pollen specialists, collecting pollen from one botanical family. The remaining 26 species (52%) were classified as pollen generalists, collecting from many botanical families. Andrena species fell into three broad foraging groups: (1) spring-flying species foraging predominantly from woody plants; (2) spring-flying species specializing on herbaceous ephemerals; and (3) summer-flying species specializing on herbaceous prairie plant species. Species of Nearctic Andrena specialized on pollens from Asteraceae, Geraniaceae, Hydrophyllaceae and Montiaceae or avoided them almost entirely. Botanical families that hosted specialized bees showed a higher variation in utilization by the Andrena community than botanical families without specialists. In contrast, Palaearctic species showed little temporal partitioning and low variation in the utilization of different botanical families. This pattern of pollen use supports previous findings that pollens from certain botanical families cannot be used as a food source without physiological adaptations, but that this phenomenon is more pronounced in the Nearctic Andrena fauna. ADDITIONAL KEYWORDS: Apoidea-Asteraceae-evolution-host plant specialization-oligolecty-pollen mixing-polylecty-solitary bee.
... The high protein content and variety of amino acids found in bee-collected pollen have been reported by many researchers (Herbert and Shimanuki 1978;Loper and Cohen 1987; Szczesna 2006;Weiner et al. 2010), most of which examined pollen collected by A. mellifera. Silva et al. (2014) investigated the amino acid content of pollen from the stingless bee species Melipona subnitida from Brazil. ...
... Adult and larval development both depend on pollen and nectar, as their primary nutritional sources, containing sufficient levels of methionine (Szczesna, 2006;Michener, 2007). Consequently, honey bees are unable to rear broods on pollen deficient in methionine (Loper and Cohen, 1987;Nicolson and Human, 2013). Based on bee foraging behavioral studies, it has been suggested that bees avoid plant species with florets deficient in methionine quantity or with protein quality low in methionine (McCaughey et al., 1980;Nicolson and Human, 2013). ...
Methionine is an essential/indispensible amino acid nutrient required by adult and larval honey bees (Apis mellifera L. [Hymenoptera: Apidae]). Bees are unable to rear broods on pollen deficient in methionine, and reportedly behaviorally avoid collecting pollen or nectar from florets deficient in methioinine. In contrast, it has been demonstrated that methionine is toxic to certain pest insects; thus it has been proposed as an effective biopesticide. As an ecofriendly integrated pest management agent, methionine boasts a novel mode of action differentiating it from conventional pesticides, while providing non-target safety. Pesticides that minimize collateral effects on bees are desirable, given the economic and ecological concerns about honey bee health. The aim of the present study was to assess the potential impact of the biopesticide methionine on non-target adult and larval honey bees. Acute contact adult toxicology bioassays, oral adult assessments and chronic larval toxicity assessments were performed as per U.S. Environmental Protection Agency (EPA) requirements. Our results demonstrated that methionine fits the U.S. EPA category of practically nontoxic (i.e. lethal dose to 50% mortality or LD50 > 11µg/bee) to adult honey bees. The contact LD50 was > 25µg/bee and the oral LD50 was > 100µg/bee. Mortality was observed in larval bees that ingested DL-methionine (effective concentration to 50% mortality or EC50 560µg/bee). Therefore, we conclude that methionine poses little threat to the health of the honey bee, due to unlikely exposure at concentrations shown to elicit toxic effects.
... acids and proteins are known to play crucial role in bee metabolism, growth and development 20 . For this reason, they are often used as a proxy to assess pollen quality 21,22 . According to available data, crude protein content (i.e., evaluated from nitrogen content) of pollen varies from 2.5% to 61% (i.e., w/w dry pollen) while the total amino acid concentration ranges approximately from 20% to 50% (i.e., w/w dry pollen) 17,18 . ...
It is now well established that invasive plants may induce drifts in the quantity and/or quality of floral resources. They are then often pointed out as a potential driver of bee decline. However, their impact on bee population remains quite unclear and still controversial, as bee responses are highly variable among species. Here, we compared the amino acid composition of pollen from three native and two invasive plant species included in diets of common pollinators in NW Europe. Moreover, the nutritional intake (i.e., pollen and amino acid intakes) of Bombus terrestris colonies and the pollen foraging behaviour of workers (i.e., visiting rate, number of foraging trips, weight of pollen loads) were considered. We found significant differences in pollen nutrients among the studied species according to the plant invasive behaviour. We also found significant differences in pollen foraging behaviour according to the plant species, from few to several foraging trips carrying small or large pollen loads. Such behavioural differences directly impacted the pollen intake but depended more likely on plant morphology rather than on plant invasive behaviour. These results suggest that common generalist bumble bees might not always suffer from plant invasions, depending on their behavioural plasticity and nutritional requirements.
... With few exceptions, all essential amino acids are found (Human and Nicolson 2006;González-Paramás et al. 2006;Szczesna 2006b;Bogdanov 2012a), which represent from 12 to 43% of the total amino acid level (González-Paramás et al. 2006;Szczesna 2006b;Martins 2010;Yang et al. 2013;Komosinska-Vassev et al. 2015). The quantity of each essential amino acid is variable, since there is variation in pollen grain composition between plant species (Loper and Cohen 1987). It is believed that bees, owing to learning acquired during foraging, seek pollen sources which better suit their needs for these compounds (Cook et al. 2003), and if necessary, they may seek more than one species, with the aim of obtaining a product that meets their nutritional requirements. ...
Bee pollen is produced by bees as a nutrient source in the hive. Its composition varies according to the region where it is produced and also with the collection and processing conditions. Proteins are the main substances of this product; however, important micronutrients and bioactive compounds are also present. Many studies have been conducted with the aim of determining the chemical composition of the bee pollen, and the results of some of these studies will be presented in this chapter. The contents of proteins and amino acids, lipids and fatty acids, vitamins, minerals and phenolic compounds in samples collected in different countries will be discussed, considering the botanical origin and other factors that influenced these parameters.
... . ﺑﻪ را ﺑﺎﻻﯾﯽ ارزش ﮔﻞ ﮔﺮده اﺳﺖ داده اﺧﺘﺼﺎص ﺧﻮد ﺑﻪ ﭘﺮوﺗﺌﯿﻨﯽ ﻣﻨﺒﻊ ﯾﮏ ﻋﻨﻮان [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43] . ...
در این آزمایش به نظر رسید که انتخاب زنبورهاي عسل براي جمع آوري گرده گل، الزاما براي زنبوردار اقتصادي نیست، اما می تواند
براي محیط زیست اقتصادي باشد و بالعکس. لذا به نظر می رسد با مدیریت و استفاده از روش امتیازبندي، بتوان کلنی ها و محیط را
در یک تقابل مناسب انتخاب نمود. این انتخاب با توجه به کاهش گرده افشان ها و گیاهان، که خطر انقراض گونه ها را افزایش داده
است، بسیار مهم جلوه می کند. در این بررسی، زنبورعسل نژاد ایرانی از نظر جمع آوري گرده و گرده افشانی در 4منطقه، با گیاهان
جنگلی، وحشی، زراعی و مرکبات مورد بررسی قرار گرفت. این نژاد از نظر اقتصادي براي زنبورداران در روش امتیاز بندي، به ترتیب
در مناطقی با گیاهان مرکبات، وحشی، زراعی و جنگلی قرار گرفت. اما از نظر اقتصادي براي حفظ منابع طبیعی و محیط زیست کاملا
برعکس امتیازدهی شد. لذا به نظر می رسد از نظر گرده افشانی زنبورعسل ایرانی در محیط هاي جنگلی بهتر واکنش دهد ولی از نظر
اقتصادي براي زنبورداران، در باغ مرکبات پاسخ مناسب تري بدهد. به نظر می رسد، با استفاده از این روش، بتوان انتخاب کلنی ها را با
توجه به محیط زیست مورد نظر، صحیح ترانجام داد
... However, pollen is arguably the most important nutritional resource required by pollinators in spring (Branquart & Hemptinne 2000b). Studies suggest that the nutritional value of pollen for bees may be defined more accurately by the amino acid composition than by protein content (Cook et al. 2003;Loper & Cohen 1987;McCaughey 1980) and floral selection by honeybees seems to reflect pollen quality (Cook et al. 2003). de Groot (1953) determined ten essential amino acids for honeybees, and it is assumed that pollen containing more of these essential amino acids (EAAs) are of greater nutritional value for bees than those containing a lower proportion of EAAs (Cook et al. 2003). ...
In temperate climates, foraging resources for pollinating insects are especially important in early spring when animals emerge from hibernation and initiate annual life cycles. One habitat, protected under EU law, which provides resources for a range of pollinating insects, but has received little research attention, is fixed (grey) dunes. Fixed dunes often contain creeping willow (Salix repens, Salicaceae), which may be an important early season resource for obligate flower visitors. We examined the springtime activity of flower visitors in fixed dune ecosystems in relation to sugar concentration and composition in nectar, composition of essential amino acids in pollen, and floral abundance. We also investigated whether the presence or absence of S. repens influenced the abundance and species richness of three obligate flower visiting guilds (solitary bees, bumblebees and hoverflies) in eight sites along the eastern and southern coasts of Ireland.
Higher insect visitation rates were observed to species whose nectar contained greater concentrations of glucose and fructose. Solitary bee visitation rates were related to % Essential Amino Acid (EAA) in pollen and floral species richness. Ulex europeaus, and S. repens were the most abundant flowering species, but visitation rates were not related to floral abundance. Higher abundances of bumblebees and hoverflies were discovered at sites where S. repens was present. This study raises further questions about the nutritional requirements and preferences of obligate flower visitors in fixed dune ecosystems in spring time.
... The inability of bee larvae to develop on the pollen of Asteraceae is assumed to be related to either its low nutritional quality, e.g. low protein and amino acid contents [57][58][59][60], a difficulty in the extraction of essential compounds from the pollen grains [61], or an interference of toxic pollen compounds with nutrient digestion [12,13]. The finding that A. bicolor larvae develop well on the pollen of Asteraceae, which is avoided by many other polylectic species [3], suggests that this species has physiologically evolved to deal with various pollen types, a finding with a strong implication for the evolution of pollen preference in bees (see below). ...
Background
Many insects have multiple generations per year and cohorts emerging in different seasons may evolve their own phenotypes if they are subjected to different selection regimes. The bivoltine bee Andrena bicolor is reported to be polylectic and oligolectic (on Campanula) in the spring and summer generations, respectively. Neurological constraints are assumed to govern pollen diet in bees. However, evidence comes predominantly from studies with oligolectic bees. We have investigated how sensory constraints influence the innate foraging behavior of A. bicolor and have tested whether bees of different generations evolved behavioral and sensory polyphenism to cope better with the host flowers available in nature when they are active. ResultsBehavioral and sensory polyphenisms were tested in choice assays and electroantennographic analyses, respectively. In the bioassays, we found that females of both generations (1) displayed a similar innate relative reliance on visual and olfactory floral cues irrespective of the host plants tested; (2) did not prefer floral cues of Campanula to those of Taraxacum (or vice versa) and (3) did not display an innate preference for yellow and lilac colors. In the electroantennographic analyses, we found that bees of both generations responded to the same set of compounds. Conclusion
Overall, we did not detect seasonal polyphenism in any trait examined. The finding that bees of both generations are not sensory constrained to visit a specific host flower, which is in strict contrast to results from studies with oligolectic bees, suggest that also bees of the second generation have a flexibility in innate foraging behavior and that this is an adaptive trait in A. bicolor. We discuss the significance of our findings in context of the natural history of A. bicolor and in the broader context of host-range evolution in bees.
... These authors reported that about 30% of nitrogen content determined in pollen samples may be of non-protein origin, because a large part of it comes from free amino acids. MCCAUGHEY et al. (1980), and LOPER & COHEN (1987) pointed out that the nutritional quality of protein-rich pollen is reduced if the amounts of essential amino acids is low. Their studies suggested that accuracy by amino acid composition is higher than by protein content in defining the nutritional value of pollen. ...
The purpose of this study was to determine the physicochemical characteristics of pollen collected by the Amazonian stingless bees Melipona seminigra and Melipona interrupta , in order to verify whether their characteristics meet the physicochemical requirements established by the Brazilian Technical Regulation for Identity and Quality of Bee Pollen. Physicochemical analyses were performed through official analytical methods. Results of pollen analyses collected by M. seminigra and M. interrupta were respectively as follows: moisture: 53.39 and 37.12%; protein: 37.63 and 24.00%; lipids: 10.81 and 6.47%; ash: 4.03 and 2.74%; crude fiber: 9.30 and 13.65%; carbohydrates: 25.66 and 44.27%; energy: 350.47 and 331.33kcal%; pH: 3.70 and 3.34; total solids: 46.60 and 62.87%, and water activity: 0.91 and 0.85. The percentages of moisture and pH in pollen collected by both studied bees are not in agreement with the Technical Regulation for bee pollen. Since some characteristics, which are inherent to the Melipona pollen, were not in conform to the current Regulation, we recommend that further studies should be conducted to better characterize it, and correct the Regulation, if necessary.
... Although numerous studies have analyzed the amino acid contents of one or a few pollens (e.g. Nielsen et al. 1955, Solberg and Remedios 1980, Ceausescu and Mosoiu 1981, Rayner and Langridge 1985, Wu and Murry 1985, Buchmann 1986, Loper and Cohen 1987, Agarwal and Nair 1989, Erhardt and Baker 1990, Clark and Lintas 1992, no study has yet assembled sufficient data to discern taxonomic and ecological trends. Thus, it is not clear if a Jack of generalities concerning differences in amino acid content are due to a lack of broad trends or a lack of data. ...
This paper reviews the literature concerning digestion and nutrient content of pollen. Four topics are addressed in detail: 1) The mechanism of pollen digestion by animals; 2) The efficiency of mechanical and digestive removal of pollen content by various animals; 3) Range and taxonomic distribution of pollen nutrients, and 4) Adaptive hypotheses proposed to associate pollen chemistry with pollinator reward. Studies on the mechanism(s) of pollen digestion remain inconclusive, but suggest that differences in digestibility among pollen types may reflect differences in pollen wall porosity, thickness, and composition. Although hummingbirds reportedly digest pollen very poorly, most animals studied, including those that do not regularly consume pollen, can digest 50–100% of ingested grains. Overlooked and recent research of pollen protein content shows that pollen grains may contain over 60% protein, double the amount cited in some studies of pollen-feeding animals. Adaptive hypotheses that associate pollen starch and pollen caloric content with pollinator reward remain unsubstantiated when critically viewed through the lens of phylogeny.
... The amounts of essential amino acids are also a factor for measuring pollen quality. The pollens from dandelion (Asteraceae) and sunflower (Asteraceae) are deficient in several essential amino acids, and because of this, they are considered poor pollen for bees (Loper and Cohen 1987;Nicolson and Human 2013). Moreover, the nutritional value of pollen for bees also depends on their digestion, and Asteraceae pollen has low rates of digestion (Peng et al. 1985;Human et al. 2007). ...
Pollen is the main protein source for honey bees, and its quality and digestibility are important factors for bee health. We compared the effects of eight different mixed-pollen diets on queenless adult survival and physiology. The mixtures represented the pollen source for bees in a natural environment. They consisted of three to five familial pollen types, and the protein percentage varied from 8.4 to 18.1 %. The mixtures that contained mainly Asteraceae pollen were less consumed and enhanced bee mortality, suggesting that this pollen type offers poor nutritional quality and assimilation for the bees. All pollen diets promoted ovarian activation, but among the pollen-treated groups, the percentage of bees with activated ovaries was not related to the protein content of the diet, which suggests that ovarian activation may also depend on other nutrients. Survival was also positively correlated to the vitellogenin levels in the hemolymph. Our results showed that the amount of protein consumption and the pollen type influenced bee survival and physiology.
... Some Taraxacum spp. pollens do not contain the amino acid cystein and only a low fraction (less than 3% of the amino acid content) of valine, methionine, and isoleucine (Loper & Cohen, 1987). Roulston & Cane, (2000), also noted that the lack of tryptophan and phenylalanine in some Taraxacum species affects bee development. ...
Analysis of the crop content of 44 queens of Bombus terrestris captured in spring over 5 weeks revealed that pollens ingested were collected from 15 plant species. Prunus and Salix accounted for 62% of the total, by volume. Through feeding tests performed with queenless micro-colonies, consumption and nutritive value of Prunus pollen was compared to those of two other pollens: Salix, also frequently collected by queens and Taraxacum which was never found in their crop. If honeybee loads of Prunus and Taraxacum were presented to workers, Prunus consumption was 2.5 times higher than that of Taraxacum. When honeybee loads were mixed with syrup to make pollen pastes of pure Prunus or Taraxacum and blends containing 10%, 50% and 90% of the other pollen, pure Prunus paste was consumed 4 to 12 times more than pastes with 50% to 100% Taraxacum. The nutritive value of the three pure pollens was estimated by the comparison of their effect on the reproductive success of queenless micro-colonies composed of three callow workers. Prunus, Salix and Taraxacum pollen resulted in similar effects on worker survival and egg clump deposition. Taraxacum pollen significantly affected ovary maturation estimated by the delay of the first eggs laid (10.6 days) compared to Prunus and Salix (7.6 days). Taraxacum did not enable production of males whereas Salix and Prunus resulted in male offspring production (8 and 19 males per micro-colony respectively). Prunus resulted in significantly higher performances than Salix in terms of oophagy (7.6 % versus 38% of egg clumps eaten), whereas Taraxacum resulted in 88% oophagy which is significantly higher than oophagy with Salix. Therefore, oophagy would be the more discriminant criterion when pollen nutritive value has to be tested comparatively. Protein rates were 27%, 20% and 17% in Prunus, Salix and Taraxacum, respectively. Protein efficacy ratios (number of males produced / weight of protein consumed) were 10.1, 6.6, and 0, respectively. These figures suggest that an amino-acid deficiency or inadequate balance affected the nutritive value of Salix and especially Taraxacum, compared to that of Prunus.
... Par ailleurs, le pollen de certaines espèces végétales (lupin, phacélie...) est très riche en acides aminés essentiels pour les abeilles, tandis que d'autres (maïs, tournesol…) en sont moins bien pourvus. Selon Loper et Cohen (1987 ; cité dans AFSSA, 2008), un pollen pauvre en acides aminés indispensables ne permet pas le développement du couvain s'il est consommé seul. De façon générale, la consommation massive par une colonie d'un seul pollen de pauvre teneur protéique peut même mettre en danger la capacité de survie de la colonie (Jacobs, 2004 ;cité dans AFSSA, 2008). ...
This research studies an exhibition and its conception about the decline of wild bees in the mediation component of the research project UrbanBees. This project explores the hypothesis of urban space as a refuge area for wild bees. It has the particularity of being support on a large operation of mediation that combines actors from diverse backgrounds (researchers, activists, cultural mediators) positioned differently on the subject concerned. The decline of wild bees is currently called a socioscientific controversy (SSC). It is based on 4 interrelated dimensions : the actual existence of decline, its potential causes and consequences, and solutions to overcome the decline. Our study aims to characterize how the SSC is supported in the exhibition and what forms of mediation are used by actors during its conception. The results show that the uncertain character of SSC appears only very occasionally and relatively consensual manner, guided by the goals of the project. Contrariwise, the study of its conception reveals disagreements, especially between two scientists. However, they are resolved by mediators : they refocus on the points of agreement (solutions brought by the project) and the unifying concepts of Nature in the City. This leads us to define the specificities of media exhibition in the treatment of SSC compared to communication actions aimed at the participation of public and examine in parallel conception processes
... A diet of pure Helianthus reduced adult longevity and stunted development of the hypopharyngeal glands in honey bees (Schmidt et al. 1995, Pernal andCurrie 2000). Loper and Cohen (1987) believe these pollens have inadequate ratios of at least four amino acids-arginine, isoleucine, leucine and valine. ...
... However, the pollen protein content of Asteraceae is at the low end of the spectrum for bee-pollinated plants , and beekeepers consider these pollens to be a poor resource (Schmidt et al. 1987). Very poor development of two species of Osmia, generalist solitary bees, was recorded on the pollen of dandelion Tanacetum vulgare (Asteraceae) (Sedivy et al. 2011), and the inability of honeybees to rear brood on dandelion pollen has been attributed to deficiencies in several amino acids (Loper and Cohen, 1987). Bumblebees (Bombus terrestris) in micro-colonies performed poorly and reared very small larvae on sunflower pollen, compared to other pollen sources (Tasei and Aupinel, 2008). ...
The nutritional needs of bees are receiving renewed attention in the context of declining bee populations and changes in land use that threaten floral resources. We present a comprehensive analysis of the nutritional composition of sunflower (Helianthus annuus L.) pollen, comparing hand-collected, bee-collected and stored pollen. As found in previous studies, the protein content of sunflower pollen was relatively low compared to other important bee forage plants. In the cultivars tested, two essential amino acids, methionine and tryptophan, are likely to be below the minimum requirements for honeybees. Fatty acid composition showed lauric acid to be most abundant, followed by palmitic and α-linolenic acids. While sunflower offers abundant and accessible pollen, its quality may hinder bee development when it is an exclusive pollen source, and the cultivars of such mass-flowering crops may vary in value for pollinators.
... Also pollens of other species of the family Asteraceae were absolutely unsuitable as food source for T. pyri (Engel 1991;Bermúdez et al. 2010). In studies with honey bees, pollen of Asteraceae have been reported to present poor food quality for bees, mainly because of low protein content, and of a low amount or lacking some essential amino acids such as arginine or phenylalanine (Praz et al. 2008;Loper and Cohen 1987). On the other hand, pollen of the entomophilous Castanea with a high protein and nitrogen content (20.3 and 3.25 %, respectively) proved a high nutritional value for bees (Tasei and Aupinel 2008), which is confirmed for A. swirskii and horse chestnut pollen. ...
The predacious mite Amblyseius swirskii Athias-Henriot is used as a biological control agent against various pests in greenhouses. Pollen offered as supplementary food is reported to improve their fast establishment and performance. However, the nutritional suitability of different pollens for A. swirskii is not sufficiently known yet. Pollens of 21 plant species were offered to the mites as exclusive food during preimaginal development. Preimaginal mortality and developmental time have been assessed, followed by a life-table analysis of the emerged adults and a calculation of demographic parameters. Amblyseius swirskii can feed exclusively on pollen, but the nutritional value of the pollens differed significantly. Pollens of Lilium martagon and Hippeastrum sp. were toxic, causing 100 % preimaginal mortality, probably due to secondary plant compounds. Hibiscus syriacus pollen was absolutely incompatible for the juvenile and adult mites, possibly due to their external morphology, differing from all the other pollens tested and leading to 100 % preimaginal mortality also. Considering all parameters, feeding on Aesculus hippocastanum, Crocus vernus, Echinocereus sp. and Paulownia tomentosa pollens lead to the best performance of the mites. Feeding on most pollens resulted in no or low preimaginal mortality of A. swirskii, but affected significantly developmental time, adult longevity, and reproduction parameters. Commercial bee pollen was not able to improve life-table parameters compared to pure pollen of the plant species. Pollens of Helianthus annuus, Corylus avellana and a Poaceae mix were less suitable as food source and resulted in a poor performance of all tested parameters. Compared with literature data, 18 pollens tested proved to be a similar or better food source than cattail pollen, qualifying A. swirskii as a positively omnivorous type IV species. Pollens of Ricinus communis and Zea mays can be recommended as supplementary food offered as banker plants, and A. hippocastanum and Betula pendula pollen is recommended to be used as dispersible pollen in greenhouses.
Graphical Abstract
Pollen grains after feeding by A. swirskii females (a—Hibiscus; b—Horse chestnut; c—Narcissus; d—Ricinus; e—Tulip; f—A. swirskii chelicers).
... The apparently low suitability of Asteraceae pollen for bee reproduction is not restricted to the subfamily Asteroideae. Pollen of Taraxacum, which belongs to the subfamily Cichorioideae, is deficient in several amino acids essential to bees ( Herbert, Bickley & Shimanuki, 1970;Loper & Cohen, 1987), as is the pollen of many other taxa of the Asteraceae ( Wille et al., 1985;Praz et al., 2008a). This deficiency is probably the reason why adult honeybees were unable to rear brood and suffered reduced longevity when fed pure diets of Taraxacum pollen ( Herbert et al., 1970;Knox, Shimanuki & Herbert, 1971;Loper & Berdel, 1980). ...
To assess the pollen hosts of 60 western palaearctic bee species of the genus Colletes (Colletidae), we microscopically analysed 1336 pollen loads of collected females. Twenty-six species (43.3%) were found to be specialized at the level of plant family, subfamily or genus. Thirty-four species (56.7%) proved to be pollen generalists to varying degrees, visiting the flowers of up to 15 different plant families. Flowers of the subfamily Asteroideae (Asteraceae) are by far the most important pollen source, contributing 23.6% to the pollen-plant spectrum of the whole bee genus. The high significance of Asteroideae pollen is due to the large number of specialists: 14 Colletes species belonging to four different taxonomic groups harvest pollen exclusively or predominantly on flowers of the Asteroideae. By striking contrast, Asteroideae pollen plays only a marginal role in the diets of the pollen generalists: it was recorded in only 2.7% of the pollen loads and in seven out of the 34 pollen generalists. Among the few generalists exploiting Asteroideae for pollen, three closely related species have ancestors which were possibly specialized on Asteraceae. The pattern of use of Asteroideae pollen by the Colletes bees supports recent findings that this pollen possesses unfavourable or protective properties, which render its digestion difficult, and suggests that bees need physiological adaptations to successfully utilize it. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 719–733.
... Some Taraxacum spp. pollens do not contain the amino acid cystein and only a low fraction (less than 3% of the amino acid content) of valine, methionine, and isoleucine (Loper & Cohen, 1987). Roulston & Cane, (2000), also noted that the lack of tryptophan and phenylalanine in some Taraxacum species affects bee development. ...
The effect of the floral origin of pollen on the reproductive success of Bombus terrestris Latrum bumblebee (Apidae: Bombinae), was investigated by feeding micro-colonies of queenless workers with different pollen types. We used a commercial pollen blend and three unifloral pollens, Prunus, Salix, and Taraxacum. Among the unifloral pollens, pollen quality did not influence egg production, but did influence egg laying delay and larval growth. The quality of pollens varied according to their protein content and protein efficacy (PE). Pollen from Prunus (27.5% w/w protein, PE=10) resulted in the largest number of progeny, whereas Taraxacum (17.2% w/w protein, PE=0) did not result in any offspring, due to high oophagy and larval ejection. Salix (20% w/w protein) and the blend (22.8% protein) diets gave rise to intermediate reproductive outputs. When pollen quality was sufficient for larval growth, the fitness of the male offspring was not affected over the range of the experimental diets. Our results suggest that quantitative and qualitative variations of pollen proteins have considerable influence on the reproductive success of bumblebees. Furthermore, larval growth has specific nutritive demands not provided by Taraxacum pollen, which is missing two essential amino acids.
... Although numerous studies have analyzed the amino acid contents of one or a few pollens (e.g. Nielsen et al. 1955, Solberg and Remedios 1980, Ceausescu and Mosoiu 1981, Rayner and Langridge 1985, Wu and Murry 1985, Buchmann 1986, Loper and Cohen 1987, Agarwal and Nair 1989, Erhardt and Baker 1990, Clark and Lintas 1992, no study has yet assembled sufficient data to discern taxonomic and ecological trends. Thus, it is not clear if a Jack of generalities concerning differences in amino acid content are due to a lack of broad trends or a lack of data. ...
This paper reviews the literature concerning digestion and nutrient content of pollen. Four topics are addressed in detail: 1) The mechanism of pollen digestion by animals; 2) The efficiency of mechanical and digestive removal of pollen content by various animals; 3) Range and taxonomic distribution of pollen nutrients, and 4) Adaptive hypotheses proposed to associate pollen chemistry with pollinator reward. Studies on the mechanism(s) of pollen digestion remain inconclusive, but suggest that differences in digestibility among pollen types may reflect differences in pollen wall porosity, thickness, and composition. Although hummingbirds reportedly digest pollen very poorly, most animals studied, including those that do not regularly consume pollen, can digest 50–100% of ingested grains. Overlooked and recent research of pollen protein content shows that pollen grains may contain over 60% protein, double the amount cited in some studies of pollen-feeding animals. Adaptive hypotheses that associate pollen starch and pollen caloric content with pollinator reward remain unsubstantiated when critically viewed through the lens of phylogeny.
... The protein content of pollen is a reliable and direct measure of pollen quality in the diet of the honeybee (Pernal and Currie 2000), and is the major nutritional input that this resource provides to the colony. Pollen quality has the potential to exert considerable influence on colony fitness, because protein content among floral species (Stanley and Linskens 1974), and to a lesser extent, even among populations of the same species (Loper and Cohen 1987), varies widely. Fewell and Winston (1992) suggested that honeybee colonies choose pollen containing a higher nitrogen (protein) content when pollen stores within the colony are high, and accept lower-quality pollen when stores are low. ...
Individual and colony-level foraging behaviors were evaluated in response to changes in the quantity or nutritional quality of pollen stored within honeybee (Apis mellifera L.) colonies. Colonies were housed in vertical, three-frame observation hives situated inside a building, with entrances leading to the exterior. Before receiving treatments, all colonies were deprived of pollen for 5 days and pollen foragers were marked. In one treatment group, colony pollen reserves were quantitatively manipulated to a low or high level, either by starving colonies of pollen or by providing them with a fully provisioned frame of pollen composed of mixed species. In another treatment group, pollen reserves were qualitatively manipulated by removing pollen stores from colonies and replacing them with low- or high-protein pollen supplements. After applying treatments, foraging rates were measured four times per day and pollen pellets were collected from experienced and inexperienced foragers to determine their weight, species composition, and protein content. Honeybee colonies responded to decreases in the quantity or quality of pollen reserves by increasing the proportion of pollen foragers in their foraging populations, without increasing the overall foraging rate. Manipulation of pollen stores had no effect on the breadth of floral species collected by colonies, or their preferences for the size or protein content of pollen grains. In addition, treatments had no effect on the weight of pollen loads collected by individual foragers or the number of floral species collected per foraging trip. However, significant changes in foraging behavior were detected in relation to the experience level of foragers. Irrespective of treatment group, inexperienced foragers exerted greater effort by collecting heavier pollen loads and also sampled their floral environment more extensively than experienced foragers. Overall, our results indicate that honeybees respond to deficiencies in the quantity or quality of their pollen reserves by increasing the gross amount of pollen returned to the colony, rather than by specializing in collecting pollen with a greater protein content. Individual pollen foragers appear to be insensitive to the quality of pollen they collect, indicating that colony-level feedback is necessary to regulate the flow of protein to and within the colony. Colonies may respond to changes in the quality of their pollen stores by adjusting the numbers of inexperienced to experienced foragers within their foraging populations.
Traditional Chinese herbal medicine (TCHM) is the naturally available pharmaceutical with millennia of evolution from ancient China, capable of a superior therapeutic index and minimized unwanted effects on the human body. This work presents a therapeutic microrobotic platform based on pollen typhae (PT), a typical type of TCHM, fabricated by coating porous PT microspheres with Fe3O4 nanoparticles (PT robots) via electrostatic adsorption. The PT robots exhibit effective and controllable motion in various biological media upon external magnetic control and, meanwhile, preserve the inherent hemostasis property of PT. The blood clotting capacity of PT robots is attributed to their stimulation of the endogenous blood coagulation pathway and platelets with increased counts, which could be further improved by their effective magnetic propulsion. The remote magnetic control also allows the manipulation of PT robots in mice stomach, inducing enhanced binding and prolonged retention of PT robots in stomach mucosa. Moreover, PT robots upon magnetic control show an enhanced hemostatic effect in treating the mice bearing acute gastric bleeding compared with other passive groups. This work offers a facile and feasible route to integrate TCHM with manmade micromachines possessing the innate curative features of TCHM. Such a design expanded the versatility of microrobots and can be generalized to vast types of TCHM for broader biomedical applications.
Son yıllarda yaşanan yoğun bal arısı (Apis mellifera L.) ölümleri arıcılıkta birçok konunun sorgulanmasına neden olmaktadır. Arı sağlığına yönelik kimyasalların kullanımının beklenen sonuçları tam olarak vermemesi ve arı ürünlerinde kalıntı sorunu gibi yeni sorunları ortaya çıkarması nedeniyle yeni çıkış yolları aranmaktadır. Yapılan çalışmalarda arıların birçok stres faktörleri ile baş edememesinin nedenlerinden birisi olarak arıların yeterli ve kaliteli besin kaynakları ile beslenememesi olduğu düşünülmektedir. Yetersiz beslenme neticesinde, bal arısı immün sisteminin zayıflamasıyla yaygın görülen arı hastalık ve zararlılarına hedef olmaktadırlar. Arıların besin durumunun iyileştirilmesinin, arı sağlığına yönelik zorluklarla mücadelede temel amaç olması gerektiğinin arıcılar tarafından iyi anlaşılması sürdürülebilir arıcılık açısından önemlidir. Bu derleme ile mevcut araştırmalar ve yeni bilgiler ışığında bal arılarında beslemenin önemi ortaya konarak, arıcılar tarafından iyi anlaşılması hedeflenmiştir.
Forage availability has been suggested as one driver of the observed decline in honeybees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modelling framework for assessing honeybee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honeybee colony model BEEHAVE, which links foraging to in-hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honeybee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g. brood mortality). To assess overall colony viability, we developed metrics, P H and P P , which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four-crop species systems composed of cereals, oilseed rape, maize and sunflower, P H and P P were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in-hive work force, which critically reduced colony resilience. Four-crop systems composed of rye-grass-dandelion pasture, trefoil-grass pasture, sunflower and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 years, and P H (269.5 kg) and P P (108 kg) being above viability thresholds for five years. Overall, trefoil-grass pasture, oilseed rape, buckwheat and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honeybee viability and to develop land-use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.
Bees are herbivorous insects, consuming nectar and pollen throughout their life cycles. This paper is a brief review of the chemistry of these two floral resources and the implications for bee nutrition. Nectar is primarily an energy source, but in addition to sugars contains various minor constituents that may, directly or indirectly, have nutritional significance. Pollen provides bees with the protein, lipids, vitamins and minerals that are essential for larval rearing. Chemical analyses of pollen have tended to focus on the protein component of bee-collected pollens as an index of nutritional quality. However, the substantial nectar content of such samples (~ 50% dry mass) should not be ignored, especially in view of current interest in measuring the nutritional quality of floral resources for bees.
The polyphenol content of propolis has received a lot of attention due to the benign biological properties noted in the chemical composition studies. However, there are very limited studies about other chemical components found in trace amounts in nature which contribute to the therapeutic properties of propolis. The present study, therefore, investigated the amino acid and vitamin composition of propolis. Propolis harvested by 60 colonies of Apis mellifera caucasica belonged to local non-migratory beekeepers. The A. m. caucasica is known for its distinctive propolis collecting capability which native to the secluded Ardahan Province of Turkey. Vitamin (Thiamine, Riboflavin) combinations of propolis were determined using the HPLC (High-Performance Liquid Chromatography) fluorescent detector. An amino acid analysis was also performed with the UFLC (Ultra-Fast Liquid Chromatography) system consisting of binary pump and UV/VIS. Our findings record that the vitamin and amino acid content of propolis samples collected from three areas of different altitudes in the same region differed from each other. Vitamin B1 content and Vitamin B2 content ranged between 0.025-0.16 mg/100g, and 0.304-0.777mg/100g, respectively. A maximum amount of amino acid was reported as leucine, while a minimum amount of amino acid was seen as tryptophan in Ardahan propolis. Consequently, the vitamin and amino acid content of propolis, which derived from secondary plant me-tabolites of resin, varied depending on their geographical altitudes. Those vitamin and amino acids found in the propolis composition are believed to have beneficial therapeutic properties.
Nutrition is the set of processes by which a living organism transforms food for its functions. Studying nutrition allows to understanding the relationship between food intake and health of the individual. All organs for extracting energy are the digestive system, which converts sugars into glucose, fats into fatty acids, and proteins into amino acids. The objective of this study is to determine the possible influence of pollen nutrition on the honeybee health, Apis mellifera L. To ensure that nutrition, the bee is subservient to floral resources. Of pollen collected from the flowering plants, the body draws fats (or lipids), vitamins and proteins. Access to these resources is variable in quality, quantity, and diversity depending on the time and the environment. Problems of mortality and weakening of colonies are observed for some twenty years, and one of the suspected causes is the lack of availability and low nutritional value of pollen resources in agricultural areas. We therefore tested under controlled conditions the effects of quantity, quality and diversity of pollen on nurse worker physiology and on their immunity, as well as their survival. Nutrition plays a vital role in the prevention of many diseases, the effects of pollen diet were determined in the presence or absence of a biotic stressor, Nosema ceranae, whose prevalence in the colonies is very high. It is an invasive microsporidia that develops in the intestine of its host, causing various sublethal and lethal effects. Since the nutritional value of a food depends on its composition but also its digestibility, a third part focuses on the possible influence of the stressor on bee ability digestion of the proteins provided by the pollen.Our results provide knowledge on the impact of pollen depletion that may undergo the colonies in an intensive agricultural landscape. Indeed, bees starved to roughly 60%, as can be observed between two cultures massive flowering undergo disturbances at individual level (disturbances of nurse worker physiological development, reduced survival), which may make them less efficient and more susceptible to stress from the environment. In addition, we demonstrated that the nutritional value of pollen influences the Nosema ceranae‘s bee tolerance. The pollen quality is determined by the total chemical composition (proteins, amino acids, lipids, vitamins, sugars, etc ...), not only by its content of essential amino acids or proteins. Our study also demonstrated the negative effect of a diet based on maize pollen on hypopharyngeal glands development, the vitellogenin gene expression, and the bee survival. In view of the high presence of this culture in intensive agriculture areas and high exploitation by foragers, our results are discussed in terms of their impact on the proposed settlements. In these environments, the diversity of pollen resources by providing pollen of quality compensates nutritional poverty of other pollens. In our conditions, we can observe the gain of power of a polyfloral pollen in Nosema infested bees. Agro-ecological measures working to regularize, in time, the pollen contributions to the colonies, and to provide them with food diversity thus participate in building their capacity to fight against stress in the environment
Semicarbazide (SEM) is a product of the metabolism or degradation of the antimicrobial veterinary drug nitrofurazone. The drug is prohibited for use in food-producing animals in the UK, and detection of SEM is used as an indication of nitrofurazone abuse. SEM was reported in several heather honey samples tested in Scotland and Northern England in 2009, and also in two samples of wild forest honey from New Zealand in 2011. The hives from which these samples were taken were strongly considered to have been free from nitrofurazone treatment, and therefore a natural source of SEM was suspected. The natural formation of SEM has been demonstrated in certain shellfish, seaweed, eggs, and whey, with arginine and creatinine proposed as its precursors. This paper reviews the natural formation of SEM in foods to help to identify a natural source in honey. A possible source is a sudden increase in arginine levels in heather pollen shortly before and during the production of the affected honey. Other possible sources of the SEM are unidentified precursors and environmental contaminants, including urine from sheep or wild animals.
Bees are herbivorous insects, consuming nectar and pollen throughout their life cycles. This paper is a brief review of the chemistry of these two floral resources and the implications for bee nutrition. Nectar is primarily an energy source, but in addition to sugars contains various minor constituents that may, directly or indirectly, have nutritional significance. Pollen provides bees with the protein, lipids, vitamins and minerals that are essential for larval rearing. Chemical analyses of pollen have tended to focus on the protein component of bee-collected pollens as an index of nutritional quality. However, the substantial nectar content of such samples ( 50% dry mass) should not be ignored, especially in view of current interest in measuring the nutritional quality of floral resources for bees.
1. Although pollen is a vital nutritional resource for honey bees, Apis mellifera , the influence of pollen quality on their foraging behaviour is little understood.
2. In choice‐test experiments, bees showed no innate pollen‐foraging preferences, but preferred oilseed rape Brassica napus pollen over field bean Vicia faba pollen after previous foraging experience of oilseed rape.
3. The free amino acid content of oilseed rape and field bean pollen was compared using high‐performance liquid chromatography. Oilseed rape pollen contained a greater proportion of the most essential amino acids required by honey bees (valine, leucine, and isoleucine) than field bean, suggesting that oilseed rape pollen is of greater nutritional quality for honey bees than is field bean pollen.
4. Honey bee foraging preferences appeared to reflect pollen quality. The hypothesis that pollen amino acid composition affects the foraging behaviour of honey bees is discussed.
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