Nectar Collection Research Articles

Mechanistic Roles of Different Varieties of Honey on Wound Healing: Recent Update

Background Honey has been used for centuries for its medicinal benefits, where topical treatments in the folklore literature reported its beneficial role in treating different types of wounds. Despite its immense use in wound care, honey’s exact mechanism remains unclear. Purpose The present study aimed to explore and abridge the gap between honey and its molecular wound healing mechanism. Methodology An extensive literature study has been performed where these activities can be explained due to phenolic compounds, nitric oxide, non-peroxide factors, low pH, high osmolarity, and hydrogen peroxide in honey. Besides that, honey also contains carbohydrates, proteins, amino acids, lipids, minerals, and vitamins, contributing to the wound healing potential to some extent. However, these metabolites and constituents differ among different honey varieties due to the distinct nutritional requirements of different species of bees and their collection of nectar from varied sources containing different natural actives. Results The revival of honey-based wound care research has identified a few probable mechanistic pathways of honey primarily due to its anti-inflammatory, antioxidant, antimicrobial, and immunomodulatory potentials. It also promotes angiogenesis, facilitates reepithelialization, stimulates proliferation of extracellular matrix, reduces neutrophil formation, modulates production of TNF-α, IL-1β, and IL-6, and prevents secondary infection at the wound site. Conclusion The varieties of honey vary in their qualities, phenolic compounds, and safety for human use. A few of these are currently clinically employed for wound dressings. Moreover, honey can be effective for managing complicated and chronic wounds; more extensive molecular research and safety profiling would be necessary.

Study on Different Nectar Rich Flowering Plants of Few Butterfly Species at Different Habitats in Pjtsau Campus Rajendranagar, Hyderabad, India

The present study was conducted to investigate the different nectar rich flowering plants of few butterfly species at various habitats in PJTSAU campus, Rajendranagar, Hyderabad during the period from October 2022 to March 2023. The study was conducted in agricultural fields (college farm, student farm and Agricultural Research Institute (ARI)), open scrub areas, Agri biodiversity park (ABP) and botanical garden. To record the nectar plants of few butterfly species, systematic field survey through transact walk was conducted by employing visual count method (VCM) in various habitats. A total of 37 flowering plant species belongs to 20 families were visited by butterflies during the study period. Interestingly, flowering trees found to have contributed more (27.03%) followed by weeds (24.32%), cultivable crops (16.22%), herbs and shrubs with same contribution (13.51%) and the least contribution was found to have recorded with climbers (5.41%). Among the 20 families, Asteraceae (6 plant species) and Fabaceae (6 plant species) families with Yellow, white and pink colored flowers were visited more often for nectar collection. It could help to understand the locally available flora with different flower colors as source of food for few butterfly species and emphasized the need of herbaceous flora conservation to restore native butterfly species in various habitats.

Analysis of Pyrrolizidine Alkaloids in Stingless Bee Honey and Identification of a Botanical Source as Ageratum conyzoides.

Stingless bee honeys (SBHs) from Australian and Malaysian species were analysed using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for the presence of pyrrolizidine alkaloids (PAs) and the corresponding N-oxides (PANOs) due to the potential for such hepatotoxic alkaloids to contaminate honey as a result of bees foraging on plants containing these alkaloids. Low levels of alkaloids were found in these SBHs when assessed against certified PA standards in targeted analysis. However, certain isomers were identified using untargeted analysis in a subset of honeys of Heterotrigona itama which resulted in the identification of a PA weed species (Ageratum conyzoides) near the hives. The evaluation of this weed provided a PA profile matching that of the SBH of H. itama produced nearby, and included supinine, supinine N-oxide (or isomers) and acetylated derivatives. These PAs lacking a hydroxyl group at C7 are thought to be less hepatoxic. However, high levels were also observed in SBH (and in A. conyzoides) of a potentially more toxic diester PA corresponding to an echimidine isomer. Intermedine, the C7 hydroxy equivalent of supinine, was also observed. Species differences in nectar collection were evident as the same alkaloids were not identified in SBH of G. thoracica from the same location. This study highlights that not all PAs and PANOs are identified using available standards in targeted analyses and confirms the need for producers of all types of honey to be aware of nearby potential PA sources, particularly weeds.

Intelligent ADRC‐based inertia control for offshore wind farm

AbstractThis paper proposes a virtual inertia control strategy for wind farms based on auto disturbance rejection controller with artificial bee colony (ABC) algorithm. First, based on the system frequency dynamic response equation, an active disturbance rejection controller is designed according to the non‐linear feedback control law and the extended state observer to improve the anti‐interference capability of the virtual inertia control system. Second, in order to solve the problem of difficulty in tuning the parameters of the active disturbance rejection control (ADRC), an ABC algorithm based on nectar collection behaviour was proposed to iteratively optimize the parameters of ADRC. Finally, the proposed control method is effectively verified based on Matlab/Simulink. The simulation results show that compared with traditional algorithms, the proposed ABC‐ADRC can effectively control the rotor speed to adjust the frequency of the power grid system, achieve power sharing and adaptive noise elimination, reduce the complexity of parameter settings, not only improve anti‐interference ability, but also enhance the robustness of the system.

Correction: 'Thermal efficiency extends distance and variety for honey bee foragers: analysis of the energetics of nectar collection and dessication by Apis mellifera' (2019), by Derek Mitchell.

Correction: 'Thermal efficiency extends distance and variety for honey bee foragers: analysis of the energetics of nectar collection and dessication by Apis mellifera' (2019), by Derek Mitchell.

Fine structure of sensilla on the proboscis of the Indian Honey Bee Apis cerana indica Fabricius (Insecta: Hymenoptera: Apidae)

Honey bees feed on flowers from which they collect nectar and pollen and their mouth parts are designed for fluid-feedingfrom flowers. The proboscis consists of a ‘tongue’ that includes a long glossa and ends in a spoon-shaped labellum, labial palp, galea and mandibles. The sensilla on the proboscis assists in nectar feeding. A study of the chemosensory hairs on the proboscis was carried out in Apis cerana indica collected from apiaries at the foot of Western Ghats, India. Light- and scanning electron microscopy were employed. In addition, silver staining was carried out to distinguish different types of chemosensilla. The glossa has 60 sensilla chaetica that stain by silver nitrate technique. The length (110 μ), width (2 μ) and spacing of microtrichia on glossa and forked hairs on the labellum are suited for the collection of nectar due to viscosity and to reduce leakiness while feeding. The length of the glossa being short suggests that A. cerana indica feeds on small-sized flowers that are not tubular. The labial palp has sensilla chaetica A and sensilla chaetica B distinguished by their length and sensilla basiconica, all of which are silver nitrate-positive and thus chemosensory in nature. Distal galea has sensilla basiconica, sensilla chaetica A and B and sensilla coeloconica. The maxillary palp is a mechanosensory structure. The bulge on the galea near the maxillary palp has chemosensory sensilla chaetica. Mandibular hairs did not stain with silver and are hence mechanosensory. The sensilla on proboscis in A. cerana indica is comparable to mouth part sensilla in Apis mellifera and Apis florea. The position of the chemosensilla at different regions suggests their role in tasting nectar, detecting the flow of nectar, and the dimensions of the flower and pollen.

Wettability and morphology of proboscises interweave with hawkmoth evolutionary history.

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively. Using contact angle and capillary pressure to evaluate capillary action of the proboscis, we conducted a comparative analysis of wetting and absorption properties for 13 species of hawkmoths. We showed that all 13 species have a hydrophilic proboscis. In contradistinction, the proboscises of all other tested lepidopteran species have a wetting dichotomy with only the distal ∼10% hydrophilic. Longer proboscises are more wettable, suggesting that species of hawkmoths with long proboscises are more efficient at acquiring nectar by the proboscis surface than are species with shorter proboscises. All hawkmoth species also show strong capillary pressure, which, together with the feeding behaviors we observed, ensures that nectar will be delivered to the food canal efficiently. The patterns we found suggest that different subfamilies of hawkmoths use different feeding strategies. Our comparative approach reveals that hawkmoths are unique among Lepidoptera and highlights the importance of considering the physical characteristics of the proboscis to understand the evolution and diversification of hawkmoths.

FORAGING ECOLOGY and ABUNDANCE of NATIVE POLLINATORS in BITTER GOURD

An experiment is conducted in bitter gourd cropping system at Coimbatore district, to study bitter gourd floral character, the foraging ecology of native pollinators and their modes of pollination. Bitter gourd is a monoecious plant bears separate male and female flowers. Male flower blooms early followed by female flowers. Stigma receptivity of pistillate flowers was confirmed on 4th day old flower showed yellowish-green stigma with shining stigmatic exudation. The stigma receptivity last upto 24 hours after anthesis. Pollen viability test done with 2 per cent acetocarmine solution indicated that pollen collected during morning hours (0600 h) were more viable and were deeply stained, whereas pollens collected at evening hours (1700 h) remained unstained and considered as nonviable. The foraging activity of A. cerana indica and T. iridipennis begins at 0600 h and 0630 h respectively and ceased by evening 1700 h. T. iridipennis foragers spent more time in pollen collection (31.1 seconds/ flower) and nectar collection (26.14 seconds/ flower) whereas, A. cerana indica spent less time in pollen collection (8.62 seconds/ flowers) and nectar collection (3.56 seconds/ flower) respectively. A total of 17 pollinator species belongs to four orders viz., Hymenoptera, Diptera, Lepidoptera and Coleoptera have been documented and grouped based on their mode of foraging in bitter gourd flowers.

ПАЛИНОЛОГИЧЕСКОЕ ИССЛЕДОВАНИЕ МЁДА В РЕСПУБЛИКЕ БУРЯТИЯ

In recent years, agricultural production has been given the strategic task of intensifying and strengthening the production of a quality food product. Many experts testify that indicators regulated by documents, although providing sufficient information about the quality of honey, they do not allow characterizing some properties, for example, its botanical origin. The botanical type of honey is substantiated by the nectar collection area. In practice, examples are given when natural honey is falsified by introducing various impurities into it. For example, they falsify with sugar, flour, starch, sugar syrup, starch and sugar syrup, artificial honey. Palynological analysis is the most objective method for assessing the botanical origin of honey, on which many of its value and quality characteristics depend. The goal is to study the palynological composition of honey obtained in the conditions of the Republic of Buryatia, identify falsification and confirm naturalness. The studies were carried out using a Carl Zeiss Primo Star microscope. The morphometric study was carried out on a Carl Zeiss Primo Star microscope at a magnification of about 10, volume 5 in the program Zeiss Efficien tNavigation (ZEN). Results: Microscopic examination revealed crystals of various shapes in the samples: needle-shaped, star-shaped, irregular and regular geometric shapes. In natural honey, crystals should only be needle-shaped and star-shaped. According to the results of the research, it was revealed that crystals were found in 40 % of the studied samples, namely, regular and irregular geometric shapes. This indicates that honey samples are falsified and made by bees using sugar syrup or sugar. Based on a palynological study, pollen grains were found in all 20 samples studied, corresponding to their botanical origin. Solitary pollen grains of other associated plants were also found. This method of analyzing honey allows you to detect falsification of a product with sugar or powdered sugar under a microscope, as well as fungal spores, pollen grains of plants.

Stingless bee Trigona spinipes (Hymenoptera: Apidae) behavior on chayote flowers (Sechium edule)

This experiment aimed to evaluate the forage species and their effect on fruit production of the chayote crop. For this, the culture was under observation in the first ten minutes at each time, from 7:00 am to 6:00 pm, with three repetitions, in each year studied (1994, 2001, 2009 and 2016). With the exception of 2009, Trigona spinipes stingless bees were frequent and constant insects in these flowers between 8:00 am and 1:00 pm, visiting mainly male flowers for nectar collection and due to foraging behavior this stingless bee may be considered a pollinator of the chayote.

Influence of Flowering Characteristics, Local Environment, and Daily Temperature on the Visits Paid by Apis mellifera to the Exotic Crop Phacelia tanacetifolia

The opportunity to introduce Phacelia tanacetifolia is still being debated, even if the species is already employed, as it is often sown in rotational set-aside schemes or to support pollinators. Therefore, we need further evidence on its effects on the environment and its attractiveness towards pollinators. This work aims at confirming its appeal towards the honeybee in a mixed agricultural and urban environment in the north of Italy, during late spring and early autumn flowering. We assessed flowering characteristics and honeybee visitation rates by employing observational plots; we recorded resource preferences and behaviours by focal observations and video records; finally, we annotated other flower visitors. Each plant is characterised by one or more flowering stems on which not all flowers open at the same time: an increased number of flowers is, therefore, due to an increase in the number of available flowering stems. Honeybees were highly interested in lacy phacelia resources, especially in nectar collection: pollen collection may not be sufficiently rewarding for bees to dedicate time to it. The only correlation we found was between visitation rates and temperature. Other insects were recorded visiting the flowers: these were especially Hymenoptera; Coleoptera and Lepidoptera were also abundant, while relatively few individuals of Hemiptera and Diptera were recorded. Our results indicate that the mass-flowering of the species is certainly of interest to local pollinators and can be considered to counteract their decline when sown as a single species or in flower mixtures. However, further studies are needed to assess the competition of this plant with native species and its ability to self-regenerate when not purposely planted.

A Comparison of Springtime Pollen and Nectar Foraging in Honey Bees Kept in Urban and Agricultural Environments

Spring is an essential time for honey bee foraging in temperate climates. This is a period of increased brood rearing supporting colony growth and demands access to high-quality pollen and nectar resources. With the expansion of urban and agricultural landscapes, the availability of pollen and nectar producing flowers is declining in many areas. We aim to determine how patterns of spring pollen and nectar foraging differ between colonies surrounded by varying degrees of urban and agricultural intensity, as well as to assess the potential for nectar sampling to serve as a proxy for pollen collection. Thirteen apiaries in Central Ohio, along a gradient of urban and agricultural intensity, were monitored in spring of 2019 through the periodic collection of pollen and nectar samples and continuous colony weight monitoring. We found that spring honey bees in urban and agricultural areas gain comparable amounts of weight and use similar spring resources. Foraging was heavily focused on flowering trees and shrubs including Malus (apple), Salix (willow), and Prunus (cherry), until the beginning of clover bloom (Trifolium spp.). We also identified differences in pollen and nectar foraging within colonies, with nectar containing fewer species collected more evenly than matched pollen samples. These results demonstrate that honey bees in both agricultural and urban environments exhibit similar foraging patterns during the spring, and that plant species important for nectar collection are substantially different from plants important for pollen foraging, though limitations in nectar collection hinder our ability to draw definitive comparisons of pollen and nectar foraging in this region.

Supplemental bee pollination effect on the productivity of soybean grown in a low yield potential condition

Brazil is the leading soybean producing country in the world, and soybean is the major crop of Brazilian agriculture, spread over 36 million hectares during the 2020/21 season, producing almost 125 million tons. The honey bee, Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae), and other bees are known as soybean flowers visitors, being potential pollinators of the crop, normally resulting in higher soybean yields. Over the last ten years, it has been observed an increasing interest of both beekeepers and soybean growers, to place honey bee colonies close to soybean fields, using the crop as a forage source. In the majority of the reports of soybeans growers, an increase of the soybean yield was observed when following this practice, while a small number claimed no yield modification. The purpose of the present work was to study the effect of visits of individuals of A. mellifera to soybean flowers and the consequent pollination on soybean productivity, when there is a constraint to the expression of the potential crop yield. The experiments were set up in Londrina, Brazil, during the 2016/17 and 2019/20 crop seasons, in areas with known sub superficial compaction layers, preventing soybean roots from deepening in the soil, therefore restricting the absorption of water and nutrients by the plants. Treatments consisted of 1) open plots, resembling a typical grower field with free access of bees; 2) a caged plot with an A. mellifera beehive inside, and 3) a caged plot with no bees or any other potential pollinating insect inside. Results indicated no yield differences due to the pollination of soybean flowers by the bees, compared to the treatment with the absence of bee visit. Among the yield components, only pods with 1 or 2 seeds were lower on caged plots with bees on the 1st experiment. No differences were detected for all others observed parameters on 1st and for all components on 2nd experiments. Observations of the honey bee behavior demonstrated that only 27.9% of the bee visits to soybean flowers resulted in nectar hoarding, with a time lapse of 4.52 seconds for a visit to a single flower. When a flower was only tested (72.1%), without nectar collection, the average time of a honey bee visit was 1.38 seconds. New studies should be performed to verify if other biotic or abiotic stresses that depress soybean yield also prevent the expression of the benefit of bees’ pollination to soybean yield.

Pollinators community of ajwain (Trachyspermum ammi) and their role in reproductive success of quality production

To ascertain the pollinator community of ajwain (Trachyspermum ammi L.) and the potential pollinators for quality seed production, a field experiment was conducted at ICAR-National Research Centre on Seed Spices, Ajmer, Rajasthan for two years. The pollinator community of ajwain was composed with 34 insect species in 7 orders and 14 families. Most of insect pollinators started their foraging at 9.00 hr and reached their respective peak activity between 12.00 to 14.00 hr and ceased at 18.00 hr. Three honeybee species Apis florea, A. mellifera and A. dorsata foraged for nectar and pollen, whereas butterfly species foraged for nectar and all Dipteran flies foraged either for nectar collection or for both nectar and pollen. Ten floral visitors (Hymenoptera-5 species, Diptera-4 species and Coleoptera-1 species) were identified as most important and potential pollinators of ajwain crop for semi-arid region performed higher foraging rate and visitation frequency. The higher seed yield of ajwain (1364.13 kg/ha) was recorded in bee pollination (BP) plots with slightly lower than sugar attractant and open pollination mode, whereas lowest yield was obtained without insect pollination (WIP)-control (844.43 kg/ha seed yield) plots. Bee pollination services increased the seed yield of ajwain by 61.54% over control and also enhanced the seed test weight and essential oil of seed in term of quality.

On the feeding biomechanics of nectarivorous birds.

Nectar-feeding birds employ unique mechanisms to collect minute liquid rewards hidden within floral structures. In recent years, techniques developed to study drinking mechanisms in hummingbirds have prepared the groundwork for investigating nectar feeding across birds. In most avian nectarivores, fluid intake mechanisms are understudied or simply unknown beyond hypotheses based on their morphological traits, such as their tongues, which are semi-tubular in sunbirds, frayed-tipped in honeyeaters and brush-tipped in lorikeets. Here, we use hummingbirds as a case study to identify and describe the proposed drinking mechanisms to examine the role of those peculiar traits, which will help to disentangle nectar-drinking hypotheses for other groups. We divide nectar drinking into three stages: (1) liquid collection, (2) offloading of aliquots into the mouth and (3) intraoral transport to where the fluid can be swallowed. Investigating the entire drinking process is crucial to fully understand how avian nectarivores feed; nectar-feeding not only involves the collection of nectar with the tongue, but also includes the mechanisms necessary to transfer and move the liquid through the bill and into the throat. We highlight the potential for modern technologies in comparative anatomy [such as microcomputed tomography (μCT) scanning] and biomechanics (such as tracking BaSO4-stained nectar via high-speed fluoroscopy) to elucidate how disparate clades have solved this biophysical puzzle through parallel, convergent or alternative solutions.

Bee Diversity Associated with Canavalia rosea (Sw.) DC. (Fabaceae, Papilionoideae) in an Peri-Urban Patch of “Restinga”

The Restinga is one of the physiognomies of the Atlantic Forest biome with the highest degree of anthropic impact, mainly due to disordered urbanization. The impacts generate habitat loss and threaten the animals and plants that inhabit this ecosystem. In the Restinga, the psammophilous vegetation have an important role in stabilizing the sandy substrate and maintaining the pollinator community. In this study, we analyzed the floral resources offered by Canavalia rosea to floral visitors between October 2019 and September 2020, in the Municipal Natural Park of Barreto’s Restinga, in Macaé, Rio de Janeiro, Brazil. Sampling was carried out from 8:00 am to 4:00 pm, covering a 250-meter transect in the sandy cord, counting the total number of open flowers and collecting visiting bees. The morphology of C. rosea flowers was described to relate to the functional traits of visitors, related to pollen and nectar collection. The pollen load of visitors was analyzed to estimate the degree of specialization in relation to C. rosea. A total of 192 individuals of 14 bee species were captured. There was a significant relationship between the availability of floral resources, measured by the number of open flowers and the richness and abundance of bees. The greatest richness of bees was observed between January and March and the greatest abundance in January. The most frequent visiting genera in C. rosea were Eufriesea, Centris and Xylocopa. The greatest richness of pollen types was observed in Eufriesea species. Most Xylocopa individuals showed C. rosea pollen. In this study, the importance of C. rosea as a source of floral resources for fourteen species of solitary bees was demonstrated. The data generated increases the knowledge about the ecological patterns of C. rosea and its floral visitors and may contribute to the maintenance and expansion of Restinga areas in urban environments.

Biotechnological Evaluation of Bee Ethology During Honey Collection and Probiotic Properties of Honey

The influence of biotechnological factors, such as purebred families and honey base on the ethology of bees in the process of nectar collection and the species composition of the association of probiotic cultures in freshly pumped honey to bees was found out. The research was conducted using Ukrainian steppe bees. The following most typical external features of their breed, namely the length of the proboscis from 6.34 to 6.44 mm, cubital index in the range of 2.17 ± 0.04 - 2.61 ± 0.05, discoidal displacement 76 - 100 %, the shape of the edge of the wax mirror 68 - 96% of convex cases. The species composition of honey plants in typical conditions of the Forest-Steppe zone of Ukraine, their contribution to the general honey harvest during the whole beekeeping season and the formation of antibacterial defense mechanism of bees based on the association of probiotic cultures in their intestines and freshly pumped honey are analyzed. Data on differentiation of selected cultures from bee honey by cultural-morphological and biochemical properties are given. Probiotic cultures were identified by cultivation on differential media. Thus, cultures of <i>Lactobacillus plantarum and Bifidobacterium bifidum</i> were accumulated on MRS medium (solid and liquid), and <i>Enterococcus faecium</i> was accumulated on tryptone soy medium. It is shown that the quantitative characteristics of honey accumulation in the bee nest depend on a number of biotechnological factors. The main indicators that affect the ethology of bees when collecting nectar are purebred and species composition of the honey base. The results of the research serve as a basis for further studies of the ethology of the Ukrainian steppe breed of bees during honey collection, its popularization and use in large apiaries (100 and more families) according to the breed zoning plan in the Forest-Steppe zone of Ukraine and for the development of new antibacterial, specific for bees, organic products based on probiotic cultures, isolated from honey.

African endemic stingless bees as an efficient alternative pollinator to honey bees in greenhouse cucumber (Cucumis sativus L)

The current honey bee decline necessitates the use of alternative native pollinators to ensure global food security. Here, we compared the pollination behaviour and efficiency of the African honey bee (Apis mellifera) and six African endemic Meliponini (Meliponula bocandei, Dactylurina schmidti, Meliponula lendliana, Hypotrigona gribodoi, Meliponula ferruginea and Meliponula togoensis) in a greenhouse with the non-parthenocarpic cucumber variety Super Marketer. Honey bees and D. schmidti started foraging on introduction in the greenhouse, while M. lendliana and M. togoensis showed the longest delay. In most species, foragers collected nectar and pollen, excepting M. bocandei that specialized in nectar collection, and H. gribodoi and M. togoensis, specialized in pollen collection. African honey bees visited flowers the shortest, while H. gribodoi and D. schmidti had a 2-fold probing time, on average. Most stingless bees species had a lower hive activity with fewer foragers encountered per hour than for honey bees, except D. schmidti. M. bocandei, M. ferruginea, A. mellifera scutellata and H. gribodoi, yielded a seed germination percentage of around 90%. M. lendliana, M. togoensis and D. schmidti yielded a much lower seed germination percentage around 30%, which indicates that the quality of pollination was remarkably lower by using these three species. The highest sugar content was recorded in fruits from flowers pollinated by M. bocandei, African honey bees, D. schimdti or M. togoensis with the same solid content as the gold standard method, i.e., hand cross-pollination. We found that M. bocandei was the most efficient cucumber pollinator of all species tested: because pollination by this species yielded the largest and heaviest fruits and the highest seed numbers.

Consequences of the high abundance of Bombus terrestris on the pollination of Vicia faba

One of the main visitors to Fabia bean crops (Vicia faba) in South America is the invasive bumblebee species Bombus terrestris. This is particularly true in Chile, where B. terrestris was first introduced in 1997 and is now common over much of the country. In this study, we evaluated the activity of the principal pollinators of V. faba over two cropping seasons by assessing their visitation rates while distinguishing between legitimate visits, likely to lead to pollination, and nectar robbery. We then determined the net contribution of insect visitation on pod and seed set. We recorded seven species of floral visitors. Most visits (legitimate visits and robbery) were from the honeybee (Apis mellifera), with B. terrestris being the next most common visitor. In the case of B. terrestris, 87.19% of visits were nectar robbery. On average, the same flower perforation was visited 23 times by B. terrestris during the flower's lifespan. In general, the frequency of legitimate visits varied with pollinator identity and year. For B. terrestris, each flower received an average of 0.95 legitimate visits during its entire lifespan. The time spent by B. terrestris visiting flowers for both nectar robbery or pollen collection decreased after the first day of flowering suggesting resource depletion. The number of pods, total seed number, and seed weight were lower where self rather than open pollination. This suggests that open pollination increased reproductive success. We conclude that B. terrestris was likely to contribute relatively little to pollination while at the same time depleting floral resources throughout the flowers’ lifespan.

The Melliferous Conditions of the Valdai District of the Novgorod Region

The article examines the melliferous and honey-collecting conditions of the Valdai district of the Novgorod region. The area is located on the border of the northern range of natural distribution of honey bees. The climatic conditions for the life of bees and the collection of nectar by them are not easy. On the territory of the region, wild melliferous plants are widespread, secreting nectar from early spring to autumn. On the example of the territories of two apiaries of the region, the article examines the main melliferous plants that are important for obtaining marketable honey. The resources of nectar, food supply for bees have been calculated. The factors and problems on which the efficiency of collecting nectar by bees depends, taking into account local geographic and climatic factors, are considered.