Comparative assessment of various supplementary diets on commercial honey bee (Apis mellifera) health and colony performance

A healthy honey bee stock is critical to the beekeeping industry and the sustainability of the ecosystem. The quality of the supplemental diet influences the development and strength of the colony, especially during the pollen dearth period in the surrounding environment. However, the extent to which pollen substitute protein feeding affects honey bee colony parameters is not fully known. We conducted this study to test the influence of various supplemental diets on foraging effort, pollen load, capped brood area, population density, and honey yield. The treatment groups were supplied with patties of pollen substitute diets, whereas sugar syrup was given to the control group. Our results indicated that honey bees consumed a significantly higher amount of Diet 1 (45 g soybean flour + 15 g Brewer’s yeast + 75 g powdered sugar + 7.5 g skimmed milk + 7.5 g date palm pollen + 200 mL sugar syrup supplement with Vitamin C) followed by others supplemented diets. Further, pollen load, worker-sealed brood area, population strength, and honey yield differed significantly when Diet 1 was consumed instead of other supplemental diets. The proportion of biological parameters was less in the control group as compared to other treatments. This study highlights the potential of supplemental diets to improve the bee’s health and colony development when the pollens availability and diversity are insufficient.

Analysis of allergenic pollen data, focusing on a pollen load threshold statement

Airborne allergenic pollen affects a significant part of the population and the information on pollen load is a valuable tool for public health prevention. The messages should be provided in a form easily understandable for the population. The study provides new insight for the categorisation of pollen load by defining thresholds solely from aerobiological data. Using the long-term airborne pollen data of Corylus, Alnus, Betula, Poaceae, and Artemisia have been evaluated the regionality of pollen concentrations in Lithuania. SPIn and peak values of the main pollen season highlighted as regionality indicators. The largest differences between stations were found in the cases of Corylus and Artemisia.The principle enabling a group of pollen concentrations into levels has been analysed based on retrospective aerobiological data of five pollen types. Thresholds were determined by employing the lowest peak value of the pollen season and applying the 25% principle for selected pollen types. The results were verified by performing associations of defined thresholds with retrospective morbidity data of allergic rhinitis and allergic asthma in Lithuania. Determined pollen thresholds can be used in epidemiological studies requiring associations with pollen concentration. Thresholds could also complement air quality information by integrating pollen load data into public messages or contribute to the development of mHealth systems.

Novel pollen analogue technique shows bumblebees display low floral constancy and prefer sites with high floral diversity

Context There have been dramatic global declines in pollinating insects. A common land management intervention to support wild pollinators is to plant non-crop flowering plants (‘pollinator planting’). However, there are limited data on which species or spatial arrangement of planting provide maximum benefit to wild pollinators. Objectives Here we investigate which flowering species and locations are visited by free-foraging Bombus terrestris (buff-tailed bumblebees) in species-rich semi-natural grassland and woodland. Methods Two study nests of buff-tailed bumblebees were established in Wytham Woods, UK. Pollen analogue pigments were sprayed on open flowers in the study area over a period of two months, with unique colours used to identify separate sections of the study area. Pollen load analysis was used to identify forage species and foraging locations. Results Bumblebees showed low flower constancy, visiting five flower species per trip on average, and as a group the sampled bumblebees visited 36 of the 49 plant species identified in study area surveys. Many individuals foraged in multiple, spatially-discrete locations during single trips. Conclusions The positive relationship between floral diversity and pollen load species diversity, and the positive relationship between site floral diversity and frequency of visitation, suggest behavioural strategies that maximize the diversity of flower species visited, in line with the energetic costs and benefits hypothesis. This supports recommendations for pollinator plantings with high species diversity, potentially spread across many small forage areas across the landscape.

EFFECT OF TEMPERATURE STORAGE ON THE CONTENT OF VITAMIN A IN MONOFLORAL POLLEN POLLEN

Проблема и цель. В статье представлены результаты влияния различных температурных режимов хранения на содержание витамина А в образцах монофлерной пыльцевой обножки. Целью исследования было сравнительное изучение влияния температурных режимов на содержание витамина А в образцах монофлерной пыльцевой обножки. Методология. Для проведения эксперимента были использованы образцы пыльцевой обножки, собранные на пасеках Рязанской области. Заготовленные, высушенные образцы поместили на хранение в течение 3, 6 и 12 месяцев при разных температурных режимах (+18ºC, +5ºC и -18ºC).По истечении каждого срока хранения образцы были исследованы на содержание витамина А. Исследования проводились в научно-исследовательской лаборатории ФГБНУ «ФНЦ пчеловодства».Определение содержания витамина А выполнено согласно ГОСТ 34253-2017 Продукты пчеловодства. Метод определения витамина А. Результаты. В результате исследования было подтверждено, что при хранении наблюдается снижение содержания витамина А во всех пяти образцах монофлерной пыльцевой обножки. Полученные результаты свидетельствуют о том, что наибольшее содержание витамина А принадлежит образцам, которые хранились при температуре -18ºC; оно составило в среднем 85,2+4,1% от первоначального значения. Разброс значений витамина А зависел от ботанического происхождения образцов. Так, в образце №3 (Одуванчик лекарственный Taraxacum ofcinale Wigg) наблюдалось наибольшее количество витамина А, тогда как у образца №4 (Синяк обыкновенный Echium vulgare.) этот показатель минимальный из показателей всех представленных образцов. Заключение. Полученные результаты свидетельствуют о том, что хранение пыльцевой обножки в условиях отрицательных температур способствует наибольшему сохранению витамина А. Видовая принадлежность пыльцевой обножки является определяющим фактором ее химического состава и активности биологических свойств. Problem and purpose. The article presents the results of the infuence of diferent temperature storage conditions on the content of vitamin A in samples of monoforal pollen load. The purpose of the study was to compare the efect of temperature conditions on the content of vitamin A in samples of monoforal pollen load. Methodology. For the experiment, samples of pollen load collected in apiaries of Ryazan region were used. The prepared, dried samples were stored for 3, 6 and 12 months at diferent temperature conditions (+18º C, +5º C and -18º C). At the end of each storage period, the samples were tested for vitamin A content. The study took place in the research laboratory of Federal State Budgetary Research Center of Beekeeping. Vitamin A content was determined in accordance with GOST 34253-2017 Bee products. Method for determining vitamin A. Results. As a result of the study, it was confrmed that when storage, there was a decrease in the content of vitamin A in all fve samples of monoforal pollen load. The results showed that the highest content of vitamin A belonged to the samples that were stored at a temperature of -18° C and averaged 85.2+4.1 % of the original value. The variation in vitamin A values depended on the botanical origin of the samples. For example, sample 3 (Dandelion Taraxacum ofcinale Wigg) had the highest amount of vitamin A, while sample 4 (viper's bugloss, Echium vulgare) had the lowest amount of all the samples. Conclusion. The results obtained indicate that the storage of pollen load in conditions of negative temperatures contributes to the greatest preservation of vitamin A. The botanical origin of pollen load is a determining factor in its chemical composition and activity of biological properties.

How will climate change alter the dynamics of airborne pollen and pollen load of allergenic plants?

Summary Background Globally, climate change is being observed. Pollen allergies have been increasing since the middle of the last century. Outdoors, sensitization against pollen allergens is responsible for the highest prevalence of allergies of eyes and airways. Hence, the following two questions arose: (1) How does climate change become manifest locally–regionally, and do temperatures and precipitation have to be considered exceptional in 2018? (2) How do changing meteorological conditions impact on pollination and pollen load? Methods Pollen data of the main allergenic plants—collected at the pollen monitoring station Linz, Upper Austria—were analysed; 2018 was compared to the years 1993–2017. By means of statistical methods, the impact of meteorological parameters on pollen seasons and pollen load were examined. Results Climate change was confirmed for the region. The regional climate has shifted from moderate to warmer and drier (semi-arid) conditions. Preseasonal cumulated meteorological parameters determined flowering and pollen seasons (PS). Start and duration of the pollination of hazel, alder, birch, and grass followed other rules than the seasonal pollen production, termed seasonal pollen integral (SPIn). By its hybrid character, the model-year 2018 offered the unique chance to generate and explain different scenarios of pollen emission and transmission. For the start of flowering of hazel (Corylus), alder (Alnus) and birch (Betula), the coincidence of cumulated mean daily warmth (MDWcumul) and a distinct threshold for the highest temperature of a day (HTD) is necessary and species-specific. In 2018, the earliest begin of the pollen season (PSB) was observed. Frost delayed the PSB. Preseasonal frost as well as cool temperatures caused SPIn of alder and birch to rise, whereas SPIn of hazel were increased by warmer temperatures. Warm weather prolonged pollen seasons of early flowering plants. Heat combined with drought shortened PS of birch in 2018. Cumulated relative humidity (RHcumul) correlated highly significant with the PSB of grasses. Warm and dry conditions in 2018 caused the earliest PSB of grass since 1993. Over the years, SPI and major pollen peaks of grasses have decreased, primarily due to dryness. Conclusion The assumption that climate warming in Linz over 26 years should have increased pollen concentrations of allergenic plants was not confirmed. On the contrary, trend analyses showed that the pollen load has decreased. Hence, the increase in sensitization to pollen allergens and of the prevalence of pollen allergies ask for other explanations.

Different Pollinators’ Functional Traits Can Explain Pollen Load in Two Solitary Oil-Collecting Bees

Functional traits have been shown to be a good predictor of pollen load for some pollinator bee species, but little is known about solitary bees. In this study, I used two solitary oil-collecting bees to explore the impact of functional traits on the pollen load of two oil-secreting Calceolaria species. I therefore measured the visitation frequency, the time spent manipulating the flower, pollinator body size and pollen load for each bee species. The results reveal that each pollinator visits different Calceolaria species (C. cavanillesii and C. filicaulis) for pollen and/or oil and at least another four herb species for pollen in different proportions. In addition, each bee species presents different functional traits that affect Calceolaria pollen load. For C. chilensis, it was only its body size that affected the Calceolaria pollen load, while in C. subcaeruleus, both body size and handling time together account for its pollen load. Overall, these results highlight the role of pollinators’ functional traits in different stages of the pollination process, and even more in specialized plant-pollination systems.

Pollen load and distribution on the body of Elaeidobius kamerunicus Faust. (Coleoptera: Curculionidae) within oil palm plantations

<p>The African oil palm weevil,<strong> </strong><em>Elaeidobius kamerunicus</em> is an effective pollinator of oil palm. Each individual palm produces exclusively male or female inflorescence so that the success of pollination depends on the ability of the pollinator to transfer pollen from male to female flowers. The objective of this research was to study the amount of pollen carried by <em>E. kamerunicus</em> between male and female inflorescences (pollen load) and the amount of pollen carried on each part of the weevil’s body (pollen distribution). Fifty each of male and female <em>E. kamerunicus</em> individuals were collected from male and female flowers on trees in 3 locations: Siantar (North Sumatra), Dramaga (West Java), and Morowali (Central Sulawesi). Data on pollen load and pollen distribution on the weevil’s body were analyzed using <em>ImageJ</em> software. Results show that <em>E. kamerunicus</em> individuals collected more pollen from male flowers than from female flowers. In addition, male insects carried more pollen on their bodies than female insects. Pollen distribution on weevil body parts was highest on the elytra, followed by the thorax, abdomen, legs, and head respectively.</p>