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Competition among pollinators for floral resources is a phenomenon of both basic and applied importance. While competition is difficult to measure directly under field conditions, it can be inferred indirectly through the measurement of floral resource depletion. In this study, we conducted a pollinator exclusion experiment to calculate nectar depletion rates in summer across 16 grassland sites in the German regions of Franconia and Saxony‐Anhalt. Overall depletion rates were estimated at 95% in Franconia and 79% in Saxony‐Anhalt, indicating strong nectar limitation and likely competition among pollinators for nectar. Despite being ubiquitous in our study regions, honey bees were scarce at our sites at the time of nectar sampling. This demonstrates that wild pollinators alone are capable of massive nectar depletion, and the addition of managed honey bees to wild pollinator communities may intensify already competitive conditions. Nevertheless, the manifest diversity of the pollinator communities at our sites indicates that other factors, such as non‐trophic constraints or temporal variation in nectar limitation, can mitigate competitive exclusion despite immediate conditions of acute nectar scarcity. [ABSTRACT FROM AUTHOR]

Summary: A few Capsicum (pepper) species produce yellow‐colored floral nectar, but the chemical identity and biological function of the yellow pigment are unknown.A combination of analytical biochemistry techniques was used to identify the pigment that gives Capsicum baccatum and Capsicum pubescens nectars their yellow color. Microbial growth assays, visual modeling, and honey bee preference tests for artificial nectars containing riboflavin were used to assess potential biological roles for the nectar pigment.High concentrations of riboflavin (vitamin B2) give the nectars their intense yellow color. Nectars containing riboflavin generate reactive oxygen species when exposed to light and reduce microbial growth. Visual modeling also indicates that the yellow color is highly conspicuous to bees within the context of the flower. Lastly, field experiments demonstrate that honey bees prefer artificial nectars containing riboflavin.Some Capsicum nectars contain a yellow‐colored vitamin that appears to play roles in (1) limiting microbial growth, (2) the visual attraction of bees, and (3) as a reward to nectar‐feeding flower visitors (potential pollinators), which is especially interesting since riboflavin is an essential nutrient for brood rearing in insects. These results cumulatively suggest that the riboflavin found in some Capsicum nectars has several functions. [ABSTRACT FROM AUTHOR]

Cover LegendCapsicum pubescens: open purple flower with yellow nectar droplets and unopened bud against a black background. Image courtesy of Evin Magner (Magner et al., pp. 1991‐2007).. [Extracted from the article]

Nectar-foraging bees change their use of floral resources as plant species appear in the environment and disappear over their lifetimes. The new flowers used may involve different cues and different nectar extraction tactics. Although bumble bees can adapt to changes in floral cues and required tactics, little is known about whether bees prioritize switching tactics or floral cues when deciding which plant species to switch to. In a laboratory assay, we forced common eastern bumble bee, Bombus impatiens , workers either to switch the handling tactic they were using or to continue using the tactic but to switch the colour of artificial flowers foraged on. We examined whether bees' tendency to change their tactics was influenced by how similar in colour novel flowers were to familiar ones. We conducted a 2 × 2 factorial experiment using artificial flowers, manipulating the handling tactic that bees were initially trained to use (legitimate visit or nectar robbing) and the similarity between novel and trained colours (similar or distinct). We found that under most conditions bees preferred to switch flower colours and retain handling tactics. However, when given experience with legitimate visits and when novel flowers were markedly different in colour from those they had experienced previously, bees tended to switch tactics while continuing to forage on flowers of the same colour. These findings suggest that the similarity in colour of a new floral resource to the currently exploited resource and the flower-handling tactic used by bees both play an important role in decision making by foraging bumble bees. • We examined bumble bees' switching decisions to novel types of flowers. • Bees were trained to legitimately visit or rob blue flowers to obtain reward. • Novel (dark blue or yellow) flower rewards required the trained tactic. • Bees switched to dark blue flowers using the trained tactic. • Bees switched to robbing blue flowers when the novel flower was yellow. [ABSTRACT FROM AUTHOR]

The role of visit of pollinator insect(Chalicodoma cincta) on the production of Bean (Phaseolus vulgaris, Rose variety), were studied at Sarh in September 2021 and 2022. The experiments were made on four treatments. The activity behavior of Chalicodoma cincta on the flower were appreciated to determinate is impact on the yield. Results indicate that among seven insect species recorded on flowers, C. cincta ranked first (31.41%) and harvested nectar. Throughout the importance of the flower visit, this insect provoked a significant increase of the podding rate (30.45 %), the mean number of seeds per pod (22.42 %) and the percentage of normal seeds (32.81%). The conservation and installation of C. cincta nests close the plantation fields is recommended to improve pod production. [ABSTRACT FROM AUTHOR]

Sunflower production depends on pollination by honey bees, Apis mellifera L., and wild bees. For wild sunflower oligoleges, preference for various sunflower lines seems to reflect the quantity (or accessibility) of floral rewards, with floret size (≈accessibility of sunflower nectar) appearing most important. However, it is less clear how honey bees, a key generalist, are affected by sunflower floral traits. The honey bee-sunflower interaction was explored to test if accessibility of nectar (≈floret size) and related floral traits explain foraging preferences and to assess potential nutritional variation in sunflower pollen. In the first two years, honey bee foraging preference increased with decreasing floret length similar to previous observations with wild pollinators. In the second year, no similar response was seen, though nectar rewards (by volume or volume × concentration) were remarkably low compared to the previous year. Pollen collected from bagged plants in the second year showed sunflower lines differed in concentrations (µg/mg ± SE) of total fatty acids and essential fatty acids. In general, it appears that honey bee responses to floral traits are similar to those of wild bees responsible for pollinating much of the sunflower crop in the central United States and that variation in the nutritional quality of sunflower pollen is greater than previously known. Because of the broad geographic distribution of the sunflower crop, additional research on how the environment influences floral rewards and sunflower-pollinator interactions may be needed. [ABSTRACT FROM AUTHOR]

Abstract:Understanding nectar sources is crucial for sustainable apiculture with Apis cerana, yet information on these sources remains limited. We conducted pollen analysis of honey and bees’ ingested nectar (mainly crop content) to determine the nectar sources of this honeybee species in West Bengal, India. Diverse pollen types were obtained from honey (33) and crop-nectar samples (47). A few pollen types came from non-nectariferous plants, and most came from actual nectariferous plants. Predominant pollen types in honey samples were Calendula officinalis, Eucalyptus tereticornis, and Peltophorum pterocarpum. The very frequent pollen types obtained from crop-nectar were Eucalyptus tereticornis, Peltophorum pterocarpum, and Tridax procumbens. In conclusion, versatile pollen types (that were obtained from honey and bee’s crop-nectar), indicating that the Asian honeybee (Apis cerana) is a generalist visitor, collect nectar from a large number of plant species. Our results also conclude that pollen analysis of bees’ crop-nectar can provide vital information about their nectar sources (excluding a few pollen types of non-nectariferous plants) in addition to the traditional honey analysis. [ABSTRACT FROM AUTHOR]

Summary The globally changing climatic condition is increasing the incidences of drought in several parts of the world. This is predicted and already shown to not only impact plant growth and flower development, but also plant–pollinator interactions and the pollination success of entomophilous plants. However, there is a large gap in our understanding of how drought affects the different flowers and pollen transfer among flowers in sexually polymorphic species. Here, we evaluated in monoecious Styrian oil pumpkin, and separately for female and male flowers, the responses of drought stress on flower production, petal size, nectar, floral scent and visitation by bumblebee pollinators. Drought stress adversely affected all floral traits studied, except floral scent. Although both flower sexes were adversely affected by drought stress, the effects were more severe on female flowers, with most of the female flowers even aborted before opening. The drought had negative effects on floral visitation by the pollinators, which generally preferred female flowers. Overall, our study highlights that the two flower sexes of a monoecious plant species are differently affected by drought stress and calls for further investigations to better understand the cues used by the pollinators to discriminate against male flowers and against flowers of drought‐stressed plants. [ABSTRACT FROM AUTHOR]

Attracting pollinators to achieve successful reproduction is a key challenge for wild plants that may be disturbed by complex multispecies interactions in nature. Pairwise plant–pollinator interactions have traditionally been studied for decades, while ignoring other ecological players may obscure a comprehensive understanding on how plants recruit partners or combat enemies in the pollination process. Hence, integrated studies considering the inherent complexity of ecological interactions are needed, which may open up new perspectives for deciphering intricate systems and predicting ecological consequences.We examined the presence of nectar yeasts using a combination of high‐throughput sequencing, cultivation and microscopy and quantified floral herbivory by evaluating the incidence of flowers with visible holes in 13 natural populations of Iris bulleyana in the Hengduan Mountains of southwest China during 2017–2022. We combined yeast inoculation and herbivore manipulation treatments to illustrate the isolated and combined impacts of two contrasting nectarivorous organisms, the ascomycetous yeast Metschnikowia reukaufii and adult sawflies, on pollinator visitation and plant reproductive success in two populations. In the lab, we first employed gas chromatography–mass spectrometry to profile the volatile metabolites of yeast‐inoculated nectar relative to control, followed by a behavioural bioassay to test the preference of honeybees for these microbial volatiles.Yeasts commonly inhabited floral nectar and insect herbivores frequently bit holes in the perianth tube to consume nectar and nectaries. Nectar yeasts indirectly facilitated plant reproduction through increased pollinator visits, probably because of microbial metabolism as honeybees preferred nectar volatiles produced by yeasts in behavioural bioassays. Insect herbivores increased total floral visits but reduced legitimate visits by inducing legitimate‐to‐robbing behavioural changes of honeybees, thus leading to lower seed production. The detrimental effect of herbivory was mitigated by the presence of yeasts, which diminished the relative proportion of robbing visits and thereby 'rescued' flowers from reproductive failure.Synthesis: Overall, we found contrasting effects of non‐pollinator species, including both micro‐ and macro‐organisms, on plant–pollinator interactions in a biodiversity hotspot, where pollination deficit may be a ubiquitous phenomenon. Our findings suggest that both microbial and herbivory effects are likely to be important in explaining the exact causes of pollen limitation in species‐rich areas, highlighting the biological context dependence of species interactions in natural ecosystems. [ABSTRACT FROM AUTHOR]

Novel insecticides are continuously being developed for application in response to increased legal restriction of previously developed insecticides and resistance in target insects. These novel insecticides, such as flupyradifurone (FPF), remain relatively untested on non‐target organisms, including bumblebees. Further, existing tests on honeybees tend to focus on adult mortality and thus sub‐lethal effects, such as impacts on reproductive output, are neglected, despite their importance for population‐level impacts.To address if the novel insecticide FPF has sub‐lethal effects on bumblebee reproduction and behaviour, we established microcolonies and chronically exposed them to field‐realistic concentrations over a 14‐day period.We found that exposure to FPF reduced the bumblebees' reproductive output in terms of the number of larvae produced and the mean mass of each larval instar. FPF‐treated bees also stored less sucrose and constructed fewer honeypots. However, adult bumblebee mortality was similar between control and FPF‐exposed microcolonies.Our results show that field‐realistic FPF exposure leads to increased larval mortality and/or delayed larval development, as well as reduced nectar storage, without affecting adult mortality.Policy implications. Insecticides that impair bumblebee reproduction can have long‐term population‐level consequences, even if adult bees do not experience increased mortality. Despite this fact, sub‐lethal effects, such as impacts on reproduction, are not mandatorily assessed within the regulatory process. Our findings highlight the importance of determining sub‐lethal effects of pesticides across developmental stages, as well as using pollinator species other than honeybees within the regulatory process. [ABSTRACT FROM AUTHOR]

Nectar, an important reward in plant-pollinator interactions, mainly provides sugars, but also other nutrients. Nectar sugar content is known to affect pollinator preferences, while the effect of other nectar nutrients on flower visitor choices is less well understood. To explore whether nectar nutrients affect the foraging preferences of the stingless bee Trigona fulviventris, we conducted feeding choice experiments with sucrose solution enriched with either an amino acid mixture (in high and low concentrations), sodium chloride (table salt), a fatty acid mixture, or quinine (a bitter tasting substance used as negative control) against pure sucrose solution in a lowland rainforest in Costa Rica. Bees were first trained to feeders presenting either a yellow (only sucrose solution) or a blue (sucrose solution plus tested substance) visual cue that the bees could use to associate with the solution content. They were subsequently offered a choice between the blue and yellow feeders in an unrewarded test. The bees preferred pure sucrose solutions over sucrose solutions with quinine, amino acids, or fatty acids, but not over solutions with salt. Our findings indicate that T. fulviventris is able to differentiate various nutrients in nectar and prefers pure sucrose solution or sucrose solutions with salt. Sugar and salt may therefore represent important nutrients in nectar and are likely key cues to assess nectar quality in tropical stingless bees. In contrast, other nutrients appear to compromise the bees' taste for nectar and are likely obtained from other sources. [ABSTRACT FROM AUTHOR]

Floral nectar is mainly a reward in the form of food for pollinators. In early spring, when snow can still be present, pollinators have trouble finding food. The composition and productivity of nectar in flowers play an important role in a pollinator's life. It is known that low temperatures and lower humidity cause lower nectar secretion. Some studies have also shown that the quality of nectar can differ because of lower temperatures. In our research, we analysed whether abiotic factors affect nectar secretion, as well as the nectar composition of the early spring plant species Galanthus nivalis L. and Helleborus niger L. in February 2024. The study was conducted in two locations in nature. Nectar from H. niger was sampled in Tomišelj, Slovenia, whereas nectar from G. nivalis was sampled in Ljubljana, Slovenia. On four different days at three different times of day, we sampled nectar from flowers using microcapillaries. In total, we sampled 48 nectar samples from one species. We analysed soil humidity and temperature, air temperature and humidity, and UVB radiation. Our results show that nectar productivity is highest in the morning for both species. H. niger has sucrose-dominant nectar, while G. nivalis has hexose-dominant nectar. Proline, which is an important amino acid for bees, has the highest level in both species, as does the phenolic compound rutin. Environmental factors do affect nectar secretion. Soil and air temperature affect G. nivalis nectar secretion, while soil humidity affects H. niger nectar secretion. Soil and air temperature also have an effect on higher levels of sugars in both researched nectars. UVB, air humidity, and air and soil temperature seem to have an effect on phenolic compounds, but abiotic factors do not affect amino acids. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Identifying the best strawberries to produce colour stable nectars is a priority for the juice industry. Although riper strawberries produce nectars with better colour stability, variability between cultivars means that surface colour cannot be used as a single quality attribute to determine stability. Conductivity and bio‐impedance measurements can be used to differentiate ripeness of strawberries. The commercially available PEF Control System (ELEA) can measure cell disruption by measuring conductivity at different frequencies. Updated software measured strawberry conductivity at 121 frequencies between 100 Hz and 1 MHz to determine whether conductivity at these frequencies could differentiate ripeness, and be compared with the colour acceptance and stability of nectars produced from these strawberries.A high‐low ratio (HLR) was calculated by dividing the conductivity at frequency 1 MHz by conductivity at 1 kHz. HLR could be used to separate five strawberry ripeness stages, with decreasing HLR associated with increasing ripeness. HLR was then compared with the colour of nectars produced from these strawberries. Although there was a good correlation between HLR and an acceptable colour to consumers on initial production (r = −0.823, P < 0.001) and after 12 weeks of storage (−0.759, P < 0.001), cultivars differed greatly in both HLR and colour stability. Additionally, HLR had a strong correlation with firmness.The PEF Control System could be used to differentiate ripeness of strawberries by HLR, and therefore was associated with colour stability. However, no additional information on colour stability was gained from conductivity beyond what could already be deduced from differentiating ripeness based on surface colour. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Shifts between pollinator functional groups can explain major changes in floral phenotype. I document a novel case of butterfly pollination in Platycoryne, an African genus that is phylogenetically embedded in the very large Habenaria clade in the Orchidaceae. Most Habenaria species have green or white flowers and many of these have been shown to be pollinated by moths, but my observations of the orange-flowered species Platycorynus mediocris in south-central Africa showed that it is pollinated diurnally by butterflies. The nectar-producing spurs of this species are c. 15 mm in length and closely match the tongue lengths of nymphalid and pierid butterflies that visit the flowers. The rostellum arms flank the spur entrance and place sickle-shaped pollinaria on the eyes or palps of the butterflies. In contrast to the highly scented flowers of moth-pollinated Habenaria species, the flowers of P. mediocris emit very little scent. Anecdotal observations indicate that several other Platycoryne species with orange flowers are also pollinated by butterflies. I conclude that the flower colouration (orange without UV reflectance) and low emission of scent in P. mediocris reflect an important historical shift to butterfly pollination in African members of the Habenaria clade. [ABSTRACT FROM AUTHOR]

Faced with pollinator declines, cities could serve as refuges for biodiversity conservation by managing floral resources in public green spaces. Ornamental plants could play an important role in attracting pollinators because they form part of urban floral management. However, knowledge of how their floral traits respond to drought is lacking, and it is unknown whether they will be suitable for pollinators under future climates. The main objective of this study was to determine the covariation of floral traits of ornamental plant species and effects of drought on them. To this end, in a city greenhouse we measured floral traits of eight ornamental species commonly used in urban green spaces in France. We subjected the plants to a control treatment or a drought treatment, reducing the volume and frequency of watering. We observed interspecific variability in floral traits among these species and a change in covariation between the traits pollen quantity and nectar quantity in the drought treatment. Drought influenced morphological traits related to floral display more than other floral traits, with mean decreases of 28 % in floral height, 35 % in floral area and 58 % in the number of floral units. Ornamental plants seemed attractive to different morphotypes of pollinators depending on their floral unit number, nectar sugar concentration or nectar tube depth, with most visits made by Hymenoptera. These results are expected to encourage green-space managers to select urban plants according to their functional characteristics and adapt their choice of plants to climate change. [ABSTRACT FROM AUTHOR]

Sensory analysis methodologies are performed in sensory booths designed to minimise external stimuli, lacking ecological validity. Immersive environments are used to introduce contextual cues, but there is a lack of studies using mixed reality systems. The main goal of this study was to evaluate an augmented virtuality (AV) system where participants are inserted into a virtual environment and evaluate a real product, being able to interact with both dimensions. A panel of 102 consumers evaluated five samples of commercial peach nectars in three sessions, each in a different environment: public food court, living room (AV environments), and laboratory (traditional sensory booth). Consumers rated overall liking, followed by open comments, and also answered an Engagement (EQ) and a Presence Questionnaire (PQ). The type of environment only affected hedonic discrimination among samples, with the laboratory setting being the only one with sample discrimination. Nonetheless, each sample was not evaluated differently across the different environments. Concerning engagement, the environment only significantly influenced the EQ's 'Affective Value' factor, being higher when using an AV system. The level of presence in the virtual environment was significantly higher in the public food court, being significantly correlated with the EQ factor scores. [ABSTRACT FROM AUTHOR]

Understanding the complex interactions between external and internal factors that influence pollinator foraging behaviour is essential to understand ecosystem functioning, design agricultural practices or develop effective conservation strategies. However, it remains challenging to collect large and reliable data sets with reasonable personnel and workload.In this study, we present a wireless and cost‐effective robotic flower equipped with internet of things (IoT) technology that automatically offers nectar to visiting insects while monitoring visitation time and duration. The robotic flower is easy to manipulate and settings such as nectar refill rates can be remotely altered, making it ideal for field settings. The system transmits data completely wirelessly and autonomously, is mobile and easy to clean.The prototype settings allow for approximately 2 weeks of uninterrupted data collection for each battery charge. As a proof‐of‐concept application, a foraging preference dual choice experiment with bumblebees was performed. On average, more than 7000 flower visits per colony were registered daily with a set‐up consisting of 16 robotic flowers. The data show a gradual preference shift away from the pre‐trained low concentration, confirming the hypothesis of favouring sugar water with higher concentration.The robotic flower provides accurate and reliable data on insect behaviour, significantly reducing the price and/or labour costs. Although primarily designed for (bumble)bees, the system could be easily adapted for other flower‐visiting insects. The robotic flower is user‐friendly and can be easily adapted to address a wide range of research questions in pollination ecology, conservation biology, biocontrol and ecotoxicology, and allows for detailed studies on how nectar traits, flower colour and shape or pollutants affect foraging behaviour. [ABSTRACT FROM AUTHOR]

Examining the pollination biology of plant species is not only crucial for enhancing our understanding of their reproductive biology, but also essential for elucidating their adaptation and evolutionary history. Here, we investigated the breeding system and pollination biology of two closely related species in Actaea. The flower of A. purpurea is unique in the genus with purple and chartaceous (paper-like) sepals, fewer stamens with yellow anthers and purple filaments. Through three seasons of field observation and exclusion experiments, we determined that A. purpurea was primarily pollinated by a hornet species, Vespa bicolor , which also served as the most efficient pollinator. In contrast, A. japonica was primarily pollinated by large flies. Actaea purpurea exhibited a significantly higher cumulative nectar volume than A. japonica , which could be a crucial factor in attracting V. bicolor. A control experiment further demonstrated that removing the nectar leaf (petal) significantly decreased the visiting frequency of V. bicolor. Breeding system studies revealed that both species were self-compatible, yet they primarily underwent outcrossing in natural habitats. Our study presents a compelling case of possible pollinator shift in A. purpurea accompanied by morphological divergence. A more in-depth investigation of this system would offer crucial insights into the extent to which pollinators are involved in the plant speciation process and whether they contribute to reproductive isolation between closely related species. [ABSTRACT FROM AUTHOR]

Coccinellids (Coccinellidae, commonly referred to as ladybeetles, ladybugs, or ladybirds) are predatory insects that often contribute to the biological control of crop pests. Especially when prey is limited, ladybirds have been reported to consume plant resources such as nectar. However, the importance of nectar consumption to ladybird fitness is not well understood. We performed artificial feeder experiments confirming ladybird consumption of a sugar solution with carbohydrate ratios similar to nectar. Both Harmonia axyridis (harlequin ladybird) and Hippodamia convergens (convergent ladybird) depleted sugar solution in 100% of trials. We also tested the effects of aphid and sugar solution availability on longevity and fecundity of these species. Ladybirds generally died within 10 days if no food was provided but survived for 10 days when either aphids or sugar solution were available. Aphids were required for oviposition. However, when aphids were available, oviposition was 36–90% higher when sugar solution was available as well. We conclude that nectar availability has significant potential to increase ladybird fitness, so may be worth considering in the design of conservation biological control programs. [ABSTRACT FROM AUTHOR]

Elongated nectar‐feeding mouthparts have evolved in several fly families, most notably Nemestrinidae, Bombylidae and Tabanidae. Plants pollinated by these “long‐proboscid flies” tend to have relatively specialized pollination systems. In this review, I focus on the blood‐ and nectar‐feeding horsefly genus Philoliche (Tabanidae: Pangoniinae) which includes species that are important pollinators of plants in Africa and, to a lesser extent, in Asia. The nectar‐feeding mouthparts of flower‐visiting Philoliche species range from 5 to 65 mm in length, with considerable intraspecific variation evident in some taxa. Plants pollinated by Philoliche species tend to have corolla tubes (or highly exerted reproductive structures) that match the proboscis dimensions of their pollinators. Some Philoliche species and their nectar host plants show population‐level covariation in proboscis lengths and flower depths that is indicative of co‐adaptation. I summarize existing information on the distribution and morphology of Philoliche species known to pollinate flowers as well as the identity, morphology and nectar properties of plants pollinated by these insects. This survey identifies some Philoliche species as keystone pollinators. Distinct guilds of plants are adapted to different horsefly species in different geographical regions and are generally ecologically reliant on these insects, although some plant species share tabanid and nemestrinid pollinators that are functionally similar on account of convergent evolution of their proboscis dimensions. Lack of information about the larval biology, nectar host plants, fire ecology and dispersal distances of Philoliche species is the biggest challenge for the conservation of these specialized pollinators and the plants that depend on them. [ABSTRACT FROM AUTHOR]

Summary: Plants can evolve rapidly after pollinator changes, but the response of different floral traits to novel selection can vary. Floral morphology is often expected to show high integration to maintain pollination accuracy, while nectar traits can be more environmentally sensitive. The relative role of genetic correlations and phenotypic plasticity (PP) in floral evolution remains unclear, particularly for nectar traits, and can be studied in the context of recent pollinator changes.Digitalis purpurea shows rapid recent evolution of corolla morphology but not nectar traits following a range expansion with hummingbirds added as pollinators. We use this species to compare PP, heritability, evolvability and integration of floral morphology and nectar in a common garden.Morphological traits showed higher heritability than nectar traits, and the proximal section of the corolla, which regulates access to nectar and underwent rapid change in introduced populations, presented lower integration than the rest of the floral phenotype. Nectar was more plastic than morphology, driven by highly plastic sugar concentration. Nectar production rate showed high potential to respond to selection.These results explain the differential rapid evolution of floral traits previously observed in this species and show how intrafloral modularity determines variable evolutionary potential in morphological and nectar traits. [ABSTRACT FROM AUTHOR]

Many plants have evolved nutrient rewards to attract pollinators to flowers, but most research has focused on the sugar content of floral nectar resources. Concentrations of sodium in floral nectar (a micronutrient in low concentrations in nectar) can vary substantially both among and within co‐occurring species. It is hypothesized that sodium concentrations in floral nectar might play an important and underappreciated role in plant–pollinator interactions, especially because many animals, including pollinators, are sodium limited in nature. Yet, the consequences of variation in sodium concentrations in floral nectar remain largely unexplored. Here, we investigate whether enriching floral nectar with sodium influences the composition, diversity, and frequency of plant–pollinator interactions. We experimentally enriched sodium concentrations in four plant species in a subalpine meadow in Colorado, USA. We found that flowers with sodium‐enriched nectar received more visits from a greater diversity of pollinators throughout the season. Different pollinator species foraged more frequently on flowers enriched with sodium and showed evidence of other changes to foraging behavior, including greater dietary evenness. These findings are consistent with the "salty nectar hypothesis," providing evidence for the importance of sodium limitation in pollinators and suggesting that even small nectar constituents can shape plant–pollinator interactions. [ABSTRACT FROM AUTHOR]

A common management intervention to support declining wild pollinators is 'pollinator planting'. However, despite years of inclusion in conservation initiatives, global pollinator declines continue.Using the agent‐based model BEE‐STEWARD with two example species, Bombus terrestris (L. 1758) and B. pascuorum (Scopoli, 1763) (Hymenoptera: Apidae), we explore when during the year bumblebee resource demand is the highest and how that relates to seasonal changes in colony composition (numbers of eggs, larvae, pupae and adults). We then examine the impact of two‐week periods of resource scarcity across the year. Finally, we explore how enhancement with early spring‐blooming herbaceous species or trees changes colony survival and queen production.In the United Kingdom, there is a previously under‐appreciated 'hungry gap' for bumblebees in March–April, before the peak flight period, driven by the demands of larvae for protein and thermoregulation in the colony, rather than the number of adult bees.A 2‐week gap in forage availability during this period drives a 50%–87% drop in the production of daughter queens. Adding early‐blooming species in the model had significant, positive, long‐term effects on colony survival probability and daughter queen production.Pollinator‐planting initiatives in both national and international conservation schemes need to include plants that flower up to 1 month before the adults of target social pollinator species are apparent in the field, during the period that larvae dominate the colony. This approach is likely to increase colony survival and queen production, contributing towards halting and reversing global pollinator decline. [ABSTRACT FROM AUTHOR]

We analyzed the floral morphology and nectar production of several cultivars and species of Monarda representing five cultivars and four species grown in Georgia Piedmont and Montane regions. Over the course of two seasons, we detected significant differences among the samples in terms of inflorescence size, petal lobe and corolla widths and lengths, and total sugar content. M. didyma had larger glomerules, longer corollas and petal lobes, and higher nectar volume and total sugar content per flower. M. fistulosa and M. punctata had smaller glomerules, corolla and petal lobe lengths, and total sugar content per flower. Petal lobe and corolla length strongly correlated with sucrose and nectar production. Combined with data on horticultural performance, these results could be valuable in informing breeding goals for conservation-oriented landscape plants. [ABSTRACT FROM AUTHOR]

The intervention of nectar robbers in plant pollination systems will cause some pollinators to modify their foraging behavior to act as secondary robbers, consequently adopting a mixed foraging strategy. The influence of nectar robbing on pollinator behavior may be affected by spatio-temporal difference of robbing intensity, and consequently, may have different effects on the pollination of host plants. However, whether and how the nectar robbing might influence pollinators under different robbing intensity still needs further investigation. In this study, Symphytum officinale was used to detect the effect of nectar robbers on pollinators under different robbing intensity as well as their effects on plant reproductive success. Six robbing levels and three bumblebees with mixed foraging behaviors were used to evaluate the effect of different robbing intensity on pollinator behavior, visitation rate, flower longevity and pollen deposition. Our results indicated that the robbing rate increased gradually with the proportion of robbed flowers, but which did not affect the frequency of legitimate visits. The increase of robbing rate promoted the corolla abscission, and then enhanced the self-pollen deposition, but which had no significant effect on cross-pollen deposition. These results indicate that the overall fitness of S. officinale was improved by combined self and cross-pollination modes when visited by both pollinators and nectar robbers simultaneously. Although nectar robbing is not uncommon, its consequences for pollination in the interaction web have not been well studied. Our results emphasize the significance of indirect impacts in mediating the adaptive outcomes of species interactions. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate the feasibility of applying green tea extract encapsulated in yellow mombin (Spondias mombin L.) nectar. Two formulations were developed: with microencapsulated green tea extract (NM) and control (NC). NM was the variant concentration of green tea microencapsulated (4.6 g of green tea microcapsules for each 240 mL of beverage). The samples were subjected to physical-chemical and bioactive compounds analysis, such as the study of rheological behavior and sensory analysis. The addition of microcapsules resulted in changes in all of the parameters evaluated, highlighting the contribution in antioxidant activity and total phenolic compounds. The inclusion of microcapsules did not influence the rheological behavior. For the sensory analysis, it was found that NC presented better sensory acceptance. The inclusion of microcapsules of green tea extract in yellow mombin nectar presents itself as a viable alternative for the development of a new product. [ABSTRACT FROM AUTHOR]

This article, titled "Gangs in the Bar: Hornets Enjoy Nectar and Hunting During Pollination," discusses a study conducted in the Nikko Botanical Garden in Japan. The study focuses on two species of Japanese Angelica plants that are predominantly visited by hornets, including the Asian giant hornet. The study found that the hornets were important pollinators for these plants but also observed that they hunted and killed other insects while enjoying the nectar. The article suggests that this behavior may contribute to the ecological specialization of hornet-pollinated Angelica species. [Extracted from the article]

Faced with pollinator declines, cities could serve as refuges for biodiversity conservation by managing floral resources in public green spaces. Ornamental plants could play an important role in attracting pollinators because they form part of urban floral management. However, knowledge of how their floral traits respond to drought is lacking, and it is unknown whether they will be suitable for pollinators under future climates. The main objective of this study was to determine the covariation of floral traits of ornamental plant species and effects of drought on them. To this end, in a city greenhouse we measured floral traits of eight ornamental species commonly used in urban green spaces in France. We subjected the plants to a control treatment or a drought treatment, reducing the volume and frequency of watering. We observed interspecific variability in floral traits among these species and a change in covariation between the traits pollen quantity and nectar quantity in the drought treatment. Drought influenced morphological traits related to floral display more than other floral traits, with mean decreases of 28 % in floral height, 35 % in floral area and 58 % in the number of floral units. Ornamental plants seemed attractive to different morphotypes of pollinators depending on their floral unit number, nectar sugar concentration or nectar tube depth, with most visits made by Hymenoptera. These results are expected to encourage green-space managers to select urban plants according to their functional characteristics and adapt their choice of plants to climate change.

Female solitary bees collect pollen for their brood at the expense of using sugars in the nectar as fuel for flight. When flowers provide both pollen and nectar, solitary bees can refuel from the flowers to sustain pollen foraging. However, not all flowers provide both pollen and nectar. This study investigates how females of the solitary bee Andrena taraxaci orienticola secure fuel to sustain pollen foraging when flowers provide scarce nectar. By using DNA barcoding, we identified the Japanese dandelion Taraxacum platycarpum as their primary food source. This dandelion produces almost no nectar in the early morning when female bees collect almost no nectar but collect substantial amounts of pollen. We also found that these bees leave the nest with significantly more nectar at the first flight of the day than at later flights. When we restricted their fuel load by preventing nectar feeding, significantly more females failed to collect pollen on the first flight of the following day. These results suggest females hold back some part of the nectar collected at the end of a day's foraging and use it the following morning as fuel to sustain pollen foraging from flowers providing little nectar. [ABSTRACT FROM AUTHOR]

Wild rose hip fruit, pulp, beverage, nectar, as well as technological methods and tools are taken as the object of research. Rose hips have a, bright red color and a rich chemical composition, which makes it a very important raw material for industry. However, insufficient research slows down this work and makes the use of raw materials inefficient. With this in mind, the aim was to study the mechanical and technological characteristics of the femur, which are considered important for industrial processing. The reflection of ripening conditions on the mechanical, physical and chemical properties of rose hips, as well as the influence of processing methods, especially hot processing, on the quality of the product has been established. Research has shown that the percentage of fruit cultivation in the Dashkasan region was the lowest, and the highest in the Gadabay region, and the Goygol region took an intermediate position. The Latin hardness of fruits grown in Dashkasan region was 6.41 N. Gadabay region with 5.56 N and Goygol region with 5.47 N. This indicator plays an important role in the storage and processing of fruits. As a result of the treatment, the amount of dry matter in fruit, pulp and beverage increased slightly, titratable acids, ascorbic acid and pH decreased. An increase in total phenolic compounds was observed during the initial heat treatment of the raw material and was noted to be much lower in the pulp and beverage. Hot treatment had a reducing effect on the amount of ascorbic acid, which is considered one of the main components of indicators in the thigh. The obtained results can be used in individual family farms and in the food industry. [ABSTRACT FROM AUTHOR]

Southern Asian flowers offer honeybees a diversity of nectar. Based on its geographical origin, honey quality varies. Traditional methods are less authentic than DNA-based identification. The origin of honey is determined by pollen, polyphenolic, and macro-microorganisms. In this study, amplicon sequencing targets macro-microorganisms in eDNA using the ITS1 region to explore honey's geographical location and authentication. The variety of honey samples was investigated using ITS1 with Illumina sequencing. For all four honey samples, raw sequence reads showed 979,380 raw ITS1 amplicon reads and 375 ASVs up to the phylum level. The highest total number of 202 ASVs up to phylum level identified Bali honey with 211,189 reads, followed by Banggi honey with 309,207 a total number of 111 ASVs, and Lombok represents only 63 ASVs up to phylum level with several read 458,984. Based on Shannon and Chao1, honey samples from Bali (B2) and (B3) exhibited higher diversity than honey from Lombok (B1) and green honey from Sabah (B4), while the Simpson index showed that Banggi honey (B4) had higher diversity. Honey samples had significant variance in mycobiome taxonomic composition and abundance. Zygosaccharomyces and Aspergillus were the main genera found in Lombok honey, with percentages of 68.81% and 29.76% respectively. Bali honey samples (B2 and B3) were identified as having a significant amount of the genus Aureobasidium, accounting for 40.81% and 25% of the readings, respectively. The microbiome composition of Banggi honey (B4) showed a high presence of Zygosaccharomyces 45.17% and Aureobasidium 35.24%. The ITS1 analysis effectively distinguishes between honey samples of different origins and its potential as a discriminatory tool for honey origin and authentication purposes. [ABSTRACT FROM AUTHOR]

Plant‐pollinator interactions are constrained by floral traits and available pollinators, both of which can vary across environmental gradients, with consequences for the stability of the interaction. Here, we quantified how the pollination ecology of a high‐mountain hummingbird‐pollinated plant changes across a progressively more stressful environmental gradient of the Venezuelan Andes. We compared pollination ecology between two populations of this plant: Piedras Blancas (PB) and Gavidia (GV), 4450 and 3600 m asl, respectively. We hypothesised that self‐compatibility might be higher at the higher altitude site, however we found that flowers showed similar capacities for self‐compatibility in both localities. Seed production by flowers exposed to natural pollinators was significantly higher in the lower locality, where we also found higher nectar quality, larger flowers and increased frequencies of pollinator visitations. Interestingly, the population energy offered in the nectar was the same for both localities due to the higher density and floral aggregation found in the higher altitude population. Our study demonstrates how two plant populations in different environmental conditions have different pollination ecology strategies. Pollinator visitations or their absence result in trait associations in one population that are independent in the other. These population differences are not explained by differences in pollinator assembly, but by environmental heterogeneity. [ABSTRACT FROM AUTHOR]

Concerns about competition between pollinators are predicated on the assumption of floral resource limitation. Floral resource limitation, however, is a complex phenomenon involving the interplay of resource production by plants, resource demand by pollinators, and exogenous factors—like weather conditions—that constrain both plants and pollinators. In this study, we examined nectar limitation during the mass flowering of rosaceous fruit trees in early spring. Our study was set in the same region as a previous study that found severe nectar limitation in summer grasslands. We used this seasonal contrast to evaluate two alternative hypotheses concerning the seasonal dynamics of floral resource limitation: either (H1) rates of resource production and consumption are matched through seasonal time to maintain a consistent degree of resource limitation, or (H2) a mismatch of high floral resource production and low pollinator activity in early spring creates a period of relaxed resource limitation that intensifies later in the year. We found generally much lower depletion in our spring study compared to the near 100% depletion found in the summer study, but depletion rates varied markedly through diel time and across sampling days, with afternoon depletion rates sometimes exceeding 80%. In some cases, there were also pronounced differences in depletion rates across simultaneously sampled floral species, indicating different degrees of nectar exploitation. These findings generally support the seasonal mismatch hypothesis (H2) but underscore the complex contingency of nectar depletion. The challenge of future work is to discern how the fluctuation of resource limitation across diel, inter‐diel, and seasonal time scales translates into population‐level outcomes for pollinators. [ABSTRACT FROM AUTHOR]

Floral nectar sugar composition is assumed to reflect the nutritional demands and foraging behaviour of pollinators, but the relative contributions of evolutionary and abiotic factors to nectar sugar composition remain largely unknown across the angiosperms. We compiled a comprehensive dataset on nectar sugar composition for 414 insect-pollinated plant species across central Europe, along with phylogeny, paleoclimate, flower morphology, and pollinator dietary demands, to disentangle their relative effects. We found that phylogeny was strongly related with nectar sucrose content, which increased with the phylogenetic age of plant families, but even more strongly with historic global surface temperature. Nectar sugar composition was also defined by floral morphology, though it was not related to our functional measure of pollinator dietary demands. However, specialist pollinators of current plant-pollinator networks predominantly visited plant species with sucrose-rich nectar. Our results suggest that both physiological mechanisms related to plant water balance and evolutionary effects related to paleoclimatic changes have shaped floral nectar sugar composition during the radiation and specialisation of plants and pollinators. As a consequence, the high velocity of current climate change may affect plant-pollinator interaction networks due to a conflicting combination of immediate physiological responses and phylogenetic conservatism. [ABSTRACT FROM AUTHOR]

Summary: Plant pollen is rich in protein, sterols and lipids, providing crucial nutrition for many pollinators. However, we know very little about the quantity, quality and timing of pollen availability in real landscapes, limiting our ability to improve food supply for pollinators.We quantify the floral longevity and pollen production of a whole plant community for the first time, enabling us to calculate daily pollen availability. We combine these data with floral abundance and nectar measures from UK farmland to quantify pollen and nectar production at the landscape scale throughout the year.Pollen and nectar production were significantly correlated at the floral unit, and landscape level. The species providing the highest quantity of pollen on farmland were Salix spp. (38%), Filipendula ulmaria (14%), Rubus fruticosus (10%) and Taraxacum officinale (9%). Hedgerows were the most pollen‐rich habitats, but permanent pasture provided the majority of pollen at the landscape scale, because of its large area. Pollen and nectar were closely associated in their phenology, with both peaking in late April, before declining steeply in June and remaining low throughout the year.Our data provide a starting point for including pollen in floral resource assessments and ensuring the nutritional requirements of pollinators are met in farmland landscapes. [ABSTRACT FROM AUTHOR]

Summary: Floral nectar composition beyond common sugars shows great diversity but contributing genetic factors are generally unknown. Mānuka (Leptospermum scoparium) is renowned for the antimicrobial compound methylglyoxal in its derived honey, which originates from the precursor, dihydroxyacetone (DHA), accumulating in the nectar. Although this nectar trait is highly variable, genetic contribution to the trait is unclear. Therefore, we investigated key gene(s) and genomic regions underpinning this trait.We used RNAseq analysis to identify nectary‐associated genes differentially expressed between high and low nectar DHA genotypes. We also used a mānuka high‐density linkage map and quantitative trait loci (QTL) mapping population, supported by an improved genome assembly, to reveal genetic regions associated with nectar DHA content.Expression and QTL analyses both pointed to the involvement of a phosphatase gene, LsSgpp2. The expression pattern of LsSgpp2 correlated with nectar DHA accumulation, and it co‐located with a QTL on chromosome 4. The identification of three QTLs, some of the first reported for a plant nectar trait, indicates polygenic control of DHA content.We have established plant genetics as a key influence on DHA accumulation. The data suggest the hypothesis of LsSGPP2 releasing DHA from DHA‐phosphate and variability in LsSgpp2 gene expression contributing to the trait variability. [ABSTRACT FROM AUTHOR]

This study is the first to report on the presence of oestrogenic compounds in different clover flower nectar samples, in bee-deposited nectars collected from hive combs (unripe honey) and in mature honeys harvested from the same hives. The clover species investigated were two red clover (Trifolium pratense) cultivars, bred specifically for high isoflavone content, alongside a sainfoin (Onobrychis viciifolia) and a purple clover (T. purpureum) cultivar. A total of eight isoflavones, four of them non-glycosidic (biochanin A, formononetin, genistein and daidzein) the others glycosidic (sissotrin, ononin, genistin and daidzin), were targeted for identification and quantification in this study using high-performance thin-layer chromatography (HPTLC). Leaves and flower bracts of the clover samples were also investigated. Different isoflavone profiles were found across the four clover species and also in the different samples collected from each species indicating that, most likely due to the activity of honeybee (Apis mellifera) salivary enzymes, biochemical conversions take place when these bioactive compounds transition from flower nectar into ripe honey. Among the four investigated clover species, the two red clover cultivars, including their honeys, were found to contain higher levels of estrogenic compounds compared to other two cultivars. [ABSTRACT FROM AUTHOR]

Tocoyena formosa has a persistent floral nectary that continues producing nectar throughout flower and fruit development. This plant also presents an intriguing non-anthetic nectary derived from early-developing floral buds with premature abscised corolla. In this study, we characterize the structure, morphological changes, and functioning of T. formosa floral nectary at different developmental stages. We subdivided the nectary into four categories based on the floral and fruit development stage at which nectar production started: (i) non-anthetic nectary; (ii) anthetic nectary, which follows the regular floral development; (iii) pericarpial nectary, derived from pollinated flowers following fruit development; and (iv) post-anthetic nectary that results from non-pollinated flowers after anthesis. The nectary has a uniseriate epidermis with stomata, nectariferous parenchyma, and vascular bundles, with a predominating phloem at the periphery. The non-anthetic nectary presents immature tissues that release the exudate. The nectary progressively becomes more rigid as the flower and fruit develop. The main nectary changes during flower and fruit development comprised the thickening of the cuticle and epidermal cell walls, formation of cuticular epithelium, and an increase in the abundance of calcium oxalate crystals and phenolic cells near the vascular bundles. Projections of the outer periclinal walls toward the cuticle in the post-anthetic nectary suggest nectar reabsorption. The anatomical changes of the nectary allow it to function for an extended period throughout floral and fruit development. Hence, T. formosa nectary is a bivalent secretory structure that plays a crucial role in the reproductive and defensive interactions of this plant species. [ABSTRACT FROM AUTHOR]

Strawberry nectars have increased colour stability when produced from overripe, darker, and redder strawberries, with a high anthocyanin concentration. The post-harvest storage of strawberries has been shown to develop these properties. Nectars are frequently produced from strawberries rejected for fresh sale due to poor colour, which are insufficiently ripe to produce colour-stable nectars. This study investigated post-harvest anthocyanin development in strawberries to improve the colour and colour stability of nectars, which is the first time these developments were studied for beverage production. Strawberries at five ripeness stages were stored at 20 °C for 1 and 2 days prior to nectar production. The anthocyanin content of nectars was determined by a pH-differential method, and the colour stability was tracked for 12 weeks using a consumer Acceptance Factor, derived from CIELAB colour components. The anthocyanin content and colour stability were highly correlated, and both were dependent on ripening, with larger increases observed in under-ripe strawberries, and small to no improvement in overripe samples. Stored partially coloured strawberries produced nectars with equivalent colour stability to non-stored strawberries of normal ripeness. This allowed strawberries that were previously unsuitable for both fresh sale and nectar production to be used as a feedstock for nectar production, reducing food waste. [ABSTRACT FROM AUTHOR]

Watermelon beverages such as juice, ready-to-serve (RTS) and nectar were prepared with pectin as suitable stabilizing agent in order to overcome the problem of sedimentation and cloud separation of its beverages. The process technologies for preparation of watermelon beverages were also established. Physico-chemical characterization of the prepared beverages was undertaken by evaluating suspension stability index, turbidity loss rate, total soluble solids, lycopene content as well as sensory analysis. The numerical optimization results indicated that the overall optimum region for watermelon RTS beverage was predicted to be at the combined level of watermelon juice 16.33%, brix: acid ratio of 13.03 and stabilizer pectin at 0.76% level. Whereas, overall optimum region for watermelon nectar beverage was evaluated to be the combined level of watermelon juice 30%, brix: acid ratio of 19.75 and stabilizer pectin at 0.28% level. [ABSTRACT FROM AUTHOR]

Nature is aglow with numerous captivating examples of UV-fluorescence in the animal kingdom. Despite a putative role as a visual signal, exploration of UV-fluorescence in plants and its role in plant-animal interactions is lagging in comparison. Almost 50 years ago, UV-fluorescence of floral nectar, a crucial reward for pollinators, was reported for 23 flowering plant species. Since this intriguing discovery, UV-fluorescent nectar has only seldom been addressed in the scientific literature and has not been scrutinized in a phylogenetic or ecological context. Here, we report the prevalence of vibrant UV-fluorescent floral nectar across the family Cleomaceae, including the first photographic documentation in vivo colour for flowering plants. Though Cleomaceae flowers are morphologically diverse varying in colour, nectary prominence, and nectar volume, UV-fluorescent floral nectar may be a ubiquitous characteristic of the family. Fluorescence spectra show that the identity and number of fluorescent compounds in floral nectar may differ among Cleomaceae species. As Cleomaceae pollinators range from insects to bats and birds, we suggest that the UV-fluorescent floral nectar not only functions as a visual cue for the diurnal pollinators but also for the nocturnal/crepuscular pollinators in low light settings. [ABSTRACT FROM AUTHOR]

Cultivation of the mass‐flowering crop oilseed rape (OSR), Brassica napus, can provide insects with super‐abundant nectar and pollen while in bloom. Several authors have suggested breeding cultivars to produce more abundant nectar and pollen to help mitigate insect decline. However, in Britain most, 95%, OSR blooms in spring (March–May), which has been suggested to be a period of nectar surplus and reduced exploitative competition. Therefore, a large proportion of floral resources produced by OSR during this period may be uncollected. Although there has been extensive work examining OSR nectar and pollen production, no study, to our knowledge, has measured this in relation to the demand by the flower‐visiting insects. Here we quantified the percentage of nectar produced by spring blooming OSR which was uncollected in four OSR fields per year over 2 years. This was achieved by measuring the nectar in both insect accessible and inaccessible (i.e. mesh‐covered) flowers. We also quantified uncollected pollen in flowers at the beginning and the end of anthesis using a haemocytometer. Most of the nectar (69%) and a fifth of pollen (19%) was uncollected in spring blooming OSR. Based on the estimates of nectar production and observed number of insects, nectar supply per insect was estimated at 2204 μL nectar insect−1 h−1, which exceeds potential collection rates by flower‐visiting insects. Given the majority of B. napus is spring blooming, breeding cultivars of OSR which produce more nectar, while not being detrimental to flower‐visiting insects, may be of little conservation benefit. [ABSTRACT FROM AUTHOR]

Floral nectar contains microbes that can influence nectar chemistry and pollinator visitation, and these microbial communities can be affected by pollinators in turn. Some flowers are also visited by nectar robbers, which feed on nectar through holes cut in floral tissue. If nectar robbers alter nectar microbial communities, they might have unexpected impacts on pollinator visitation. We investigated whether robbing could affect nectar microbial communities directly, by introducing microbes, or indirectly, by triggering a plant response to floral damage. We applied four treatments to flowers of Tecoma × "Orange Jubilee" (Bignoniaceae) in an arboretum setting: flowers were (1) covered to exclude all visitors; (2) available to both pollinators and nectar robbers and robbed naturally by carpenter bees; (3) available to pollinators only but cut at the base to simulate nectar robbing damage; or (4) available to pollinators only. We found that nectar in flowers accessible to any visitors was more likely to contain culturable microbes than flowers from which visitors were excluded. Microbial community composition and beta diversity were similar across treatments. Among flowers containing culturable microbes, flowers available to pollinators and nectar robbers had higher microbial abundance than flowers with simulated robbing, but there were no differences between flowers available to pollinators and robbers and unwounded flowers from which robbers were excluded. Overall, our results suggest that floral damage can affect some features of nectar microbial communities, but specific effects of nectar robbing are limited compared with the influence of visitation in general. [ABSTRACT FROM AUTHOR]

Red clover (Trifolium pratense) is an important legume in agriculture for fodder and building soil fertility. Red clover flowers are also a valuable pollen and nectar source for pollinators during bloom.Farmers can choose among hundreds of commercially available red clover cultivars to plant, but the value of different cultivars for pollinators is not currently assessed or used as a recommendation criterion for farmers.Here, we compared the numbers of pollinators on 20 red clover accessions (12 cultivars and 8 breeding lines) grown under management typical for silage production in the UK in 2022 and 2023. Other potentially pollinator‐friendly traits (inflorescence density, florets per inflorescence, floret length and nectar sugar production) were also measured to help determine which would be desirable to integrate into red clover breeding programmes.Accessions varied greatly, 50‐fold, in numbers of pollinators attracted per plot and varied significantly in all other traits examined. Only inflorescence density was significantly positively related to insect abundance and species richness. These results suggest that breeding and using red clover cultivars that produce more inflorescences can increase the value of red clover to pollinators.We note that data on insect visitation can be gathered easily and could be provided to farmers to help improve the value of red clover fields to pollinators. [ABSTRACT FROM AUTHOR]

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Research on Satyrium nepalense var. ciliatum (Lindl.) Hook. f. has primarily focused on populations in Northwestern Yunnan, with limited studies on pollination syndromes and insect behavior. In addition, it is geographically limited in its breeding system studies. Here, pollination syndromes, florivory, and breeding systems of S. nepalense var. ciliatum from Liangwang Mountain (Central Yunnan, China) were investigated through field work, microscope, scanning electron microscope (SEM), and parafin section. It was revealed that the pollination syndrome was possessing out-crossing, such as bright color, a developed rostellum, nectar glands in the spur, and food hairs at the lip base. The color and nectar attracted flower visitors, and florivory was observed. Some flower visitors pollinated their companion species. Ants were identified as floral visitors for the first time in Satyrium, although substantial pollination was not observed. Ants might be potential pollinators. S. nepalense var. ciliatum possessed a mixed breeding system, including selfing, out-crossing, and apomixis, with apomixis being predominant in nature. It is suggested that the pollination syndrome, florivory, and pollination competition would contribute to its mixed breeding systems, particularly leading to the occurrence of apomixis. [ABSTRACT FROM AUTHOR]

Floral nectar is mainly a reward in the form of food for pollinators. Its composition plays an important role when pollinators choose their food. Several studies have shown that the popularity of flowers with nectar is influenced by the concentration and ratio of sugars. Here, we present the nectar chemical composition with regard to three main sugars and their concentrations in correlation with abiotic factors for the plant species Salvia pratensis L. and Salvia glutinosa L. through their 2023 flowering season. We sampled nectar using microcapillaries at three different times during the day on sites in nature. Our results show that nectar production in both species is the highest at around 12 a.m. The abiotic factor that affects nectar production in both species is the soil temperature, while UVB radiation does not influence nectar production. Air temperature and air humidity affect the nectar production of S. glutinosa, while soil humidity affects nectar production in S. pratensis. The most represented sugar in S. glutinosa nectar is sucrose, while S. pratensis nectar has more glucose and fructose. Our results show that UVB radiation has an effect on the sucrose level, although it does not have any direct effect on nectar productivity. [ABSTRACT FROM AUTHOR]