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BACKGROUND AND AIMS: Floral volatiles, visual traits and rewards mediate attraction and defence in plant-pollinator and plant-herbivore interactions, but these floral traits might be altered by global warming through direct effects of temperature or longer-term impacts on plant resources. We examined the effect of warming on floral and leaf volatile emissions, floral morphology, plant height, nectar production, and oviposition by seed predators. METHODS: We used open-top chambers that warmed plants in the field by +2-3 °C on average (+6-11 °C increase in daily maxima) for 2-4 weeks across 1-3 years at three sites in Colorado, USA. Volatiles were sampled from two closely related species of subalpine Ipomopsis with different pollinators: Ipomopsis aggregata ssp. aggregata, visited mainly by hummingbirds, and Ipomopsis tenuituba ssp. tenuituba, often visited by hawkmoths. KEY RESULTS: Although warming had no detected effects on leaf volatiles, the daytime floral volatiles of both I. aggregata and I. tenuituba responded in subtle ways to warming, with impacts that depended on the species, site and year. In addition to the long-term effect of warming, temperature at the time of sampling independently affected the floral volatile emissions of I. aggregata during the day and I. tenuituba at night. Warming had little effect on floral morphology for either species and it had no effect on nectar concentration, maximum inflorescence height or flower redness in I. aggregata. However, warming increased nectar production in I. aggregata by 41 %, a response that would attract more hummingbird visits, and it reduced oviposition by fly seed predators by ≥72 %. CONCLUSIONS: Our results suggest that floral traits can show different levels of plasticity to temperature changes in subalpine environments, with potential effects on animal behaviours that help or hinder plant reproduction. They also illustrate the need for more long-term field warming studies, as shown by responses of floral volatiles in different ways to weeks of warming vs. temperature at the time of sampling.

Plant-microbe associations are ubiquitous, but parsing contributions of dispersal, host filtering, competition and temperature on microbial community composition is challenging. Floral nectar-inhabiting microbes, which can influence flowering plant health and pollination, offer a tractable system to disentangle community assembly processes. We inoculated a synthetic community of yeasts and bacteria into nectars of 31 plant species while excluding pollinators. We monitored weather and, after 24 h, collected and cultured communities. We found a strong signature of plant species on resulting microbial abundance and community composition, in part explained by plant phylogeny and nectar peroxide content, but not floral morphology. Increasing temperature reduced microbial diversity, while higher minimum temperatures increased growth, suggesting complex ecological effects of temperature. Consistent nectar microbial communities within plant species could enable plant or pollinator adaptation. Our work supports the roles of host identity, traits and temperature in microbial community assembly, and indicates diversity-productivity relationships within host-associated microbiomes.

Drought stress during the reproductive phase of sunflower can significantly reduce achene yield by affecting inflorescence size, nectar quality, and pollinator activity. This study aimed to analyze the morphological characteristics of the reproductive region, quantify nectar sugar components, and evaluate pollinator presence and pollination success in wild Helianthus species as an important genetic resource for breeding cultivated sunflowers under drought conditions. Morphological investigations were conducted during the flowering and achene development phases with a stereo microscope and calipers. Nectar sugar concentrations were analyzed via HPLC, and pollinator presence was monitored twice a week for two months. This study highlights the correlation between evaluated traits, emphasizing their importance as yield indicators. Significant differences were observed in reproductive characters, nectar quality, and pollination success among the species. Helianthus annuus and Helianthus argophyllus exhibited superior reproductive performance with high nectar sugar concentrations and larger inflorescences, enabling successful pollination and higher achene yield. In contrast, Helianthus debilis demonstrated lower reproductive efficiency, with a higher percentage of empty achenes. These findings provide valuable insights for breeding programs, highlighting H. argophyllus and H. annuus as promising genetic resources for developing sunflower genotypes with increased yield and improved floral traits adapted to drought conditions. [ABSTRACT FROM AUTHOR]

Simple Summary: Amylase values in honey serve as a definitive biomarker for assessing the freshness of honey, with its concentration being a critical parameter for determining compliance with product standards. Bacillus subtilis contributes to amylase levels in honey sac fluid and honey, in addition to Apis mellifera secretion. Amylase activity in honey sac fluid exceeds nectar values, with the presence of B. subtilis correlating with higher amylase levels. In vitro experiments confirm B. subtilis amylase production in the presence of sucrose or honey sac fluid. Bacterial counts peak at 105 CFU/mL in the honey sac, indicating a significant role in amylase synthesis. This study establishes a novel methodology for the analysis of bacterial amylase in honey, which may improve honey quality assessment. This discovery has important implications for the standardization and quality assessment of honey, suggesting that future regulations and freshness indicators should account for the role of microflora in addition to traditional measures. Background: Amylase activity is a critical biomarker for assessing the freshness of honey. Historically, bees have been considered the sole source of honey amylase. However, recent studies suggest that Bacillus subtilis may also contribute to amylase production in the honey sac of Apis mellifera. Methods: In this study, amylase levels were measured in samples of nectar, honey sac fluid, and honey. The identification of B. subtilis in nectar, honey sac, and honey was evaluated. An in vitro bacterial culture system and a feeding experiment were developed to simulate honey sac conditions. Results: Our results showed that B. subtilis was detected in all sample groups, with the highest concentration in honey sac samples. Amylase levels in honey sac and honey samples were significantly higher than those in nectar. In the simulation experiment, amylase activity was only observed in cultures containing both B. subtilis and sucrose/nectar; no activity was detected in cultures containing only H2O or no B. subtilis. In the feeding experiment, bees fed sucrose or nectar showed higher amylase activity in their honey sacs than those fed water. Conclusions: Our data show that B. subtilis can produce amylase and offer potential for more standardized quality assessment of honey. [ABSTRACT FROM AUTHOR]

Simple Summary: Beneficial fauna in agriculture is facing problems in today's farming system, mainly due to monoculture and the irrational use of agrochemicals. A sustainable solution must be based on exploiting the ecological interactions that occur in ecosystems. For instance, different natural enemy (NEs) species need nectar and pollen as alternative foods to complete their life cycle. Therefore, the exploration and selection of native nectariferous plants must be an important consideration for better biological pest control using NEs. For one year, plant species native to Northwest Michoacán, Mexico, that hosted the highest numbers of NEs were explored. Twenty-three families of parasitoids and other predators were recorded, with few records of phytophagous insects (one to four). Thirteen species of flowering plants with the highest potential for the conservation of NEs were selected. The plants used are easy to reproduce and have complementary flowering periods that can maintain NEs populations throughout the year. The results could be helpful to enhance biological pest control and reduce the use of insecticides in agroecosystems. To identify and select wild plant species as a source of nectar and pollen for the conservation of natural enemies (NEs), with an emphasis on parasitic Hymenoptera, entomological samplings were carried out on the inflorescences of plants in the northwest of Michoacán, Mexico, in 2020. The species were selected based on the number and diversity of NEs, flowering period, phytosanitary risks (pests), and ease of multiplication. Of more than 27 plant species, NEs were recorded in 24. The Eulophid family represented 74.14% of 23 families of parasitoids recorded, and in 19 of the 23 plant species with parasitoids, the eulophid family was the most prevalent. Thirteen plant species were selected; annual species such as Tithonia tubaeformis and Stevia serrata stand out. Among the shrubs, Senecio salignus and Baccharis salicifolia stand out, as do trees such as Viguiera quinqueradiata, Thouinia villosa and Buddleja parviflora. Serjania racemosa and Phytolacca icosandra stand out for their long flowering period (>5 months) and the wide diversity of beneficial entomofauna. They are plants that reproduce easily and have a low phytosanitary risk to crops. The presence of flowering plants in agroecosystems could attract and maintain NE populations, even before pests arrive, with predictable benefits for integrated pest management. [ABSTRACT FROM AUTHOR]

Nitrogen is a crucial element that affects plant metabolic processes and indirectly influences the structure and dynamics of ecological interactions in terrestrial ecosystems. Since the invention of the Haber–Bosch process, human activity has significantly influenced the amount of nitrogen released into the environment. However, how do these overfertilization processes affect flora and fauna in urban ecosystems?In our experiments, we used elevated nitrogen concentrations to simulate terrestrial eutrophication processes in Nicotiana tabacum L. We evaluated reproductive traits such as floral morphology using geometric morphometrics. Additionally, nectar volume and solute concentration, along with other vegetative traits, were quantified. Subsequently, the impacts of these modifications on herbivory and pollination interactions in a peri‐urban environment were measured.Overfertilization resulted in notable modifications to the floral shape of the lobes, as well as a significant increase in percentage of herbivory by chewing insects, without affecting floral visitation rates. We also observed that elevated herbivory on fertilised plants did not show a direct correlation with overall pollination rates per plant or seed set. In contrast, the reduction in leaf size during the second phase of the experiment, owing to overfertilization effects, affected seed production. The roles of potential pollinators and their influence on seed quantity in control plants are discussed.Nitrogen is a crucial element not only for plants in natural terrestrial ecosystems but also plays a fundamental role in the modification and shaping of reproductive and vegetative structures. Moreover, it affects the functionality of ecological interactions of pollination and herbivory in anthropogenic environments, such as peri‐urban areas. [ABSTRACT FROM AUTHOR]

Background The frequency and intensity of droughts are expected to increase under global change, driven by anthropogenic climate change and water diversion. Precipitation is expected to become more episodic under climate change, with longer and warmer dry spells, although some areas might become wetter. Diversion of freshwater from lakes and rivers and groundwater pumping for irrigation of agricultural fields are lowering water availability to wild plant populations, increasing the frequency and intensity of drought. Given the importance of seasonal changes and extremes in soil moisture to influence plant reproduction, and because the majority of plants are flowering plants and most of them depend on pollinators for seed production, this review focuses on the consequences of drought on different aspects of reproduction in animal-pollinated angiosperms, emphasizing interactions among drought, flowering and pollination. Scope Visual and olfactory traits play crucial roles in attracting pollinators. Drought-induced floral changes can influence pollinator attraction and visitation, together with pollinator networks and flowering phenology, with subsequent effects on plant reproduction. Here, we review how drought influences these different aspects of plant reproduction. We identify knowledge gaps and highlight areas that would benefit from additional research. Conclusions Visual and olfactory traits are affected by drought, but their phenotypic responses can vary with floral sex, plant sex, population and species. Ample phenotypic plasticity to drought exists for these traits, providing an ability for a rapid response to a change in drought frequency and intensity engendered by global change. The impact of these drought-induced changes in floral traits on pollinator attraction, pollen deposition and plant reproductive success does not show a clear pattern. Drought affects the structure of plant–pollinator networks and can modify plant phenology. The impact of drought on plant reproduction is not always negative, and we need to identify plant characteristics associated with these more positive responses. [ABSTRACT FROM AUTHOR]

Background and Aims Pollinators provide critical ecosystem services, maintaining biodiversity and benefitting global food production. However, plants, pollinators and their mutualistic interactions can be affected by drought, which has increased in severity and frequency under climate change. Using two annual, insect-pollinated wildflowers (Phacelia campanularia and Nemophila menziesii), we asked how drought impacts floral traits and foraging preferences of a solitary bee (Osmia lignaria) and explored potential implications for plant reproduction. Methods In greenhouses, we subjected plants experimentally to drought to induce water stress, as verified by leaf water potential. To assess the impact of drought on floral traits, we measured flower size, floral display size, nectar volume and nectar sugar concentration. To explore how drought-induced effects on floral traits affected bee foraging preferences, we performed choice trials. Individual female bees were placed into foraging arenas with two conspecific plants, one droughted and one non-droughted, and were allowed to forage freely. Key Results We determined that P. campanularia is more drought tolerant than N. menziesii , based on measures of turgor loss point, and confirmed that droughted plants were more drought stressed than non-droughted plants. For droughted plants of both species, the floral display size was reduced and the flowers were smaller and produced less, more-concentrated nectar. We found that bees preferred non-droughted flowers of N. menziesii. However, bee preference for non-droughted P. campanularia flowers depended on the time of day and was detected only in the afternoon. Conclusions Our findings indicate that bees prefer to visit non-droughted flowers, probably reducing pollination success for drought-stressed plants. Lack of preference for non-droughted P. campanularia flowers in the morning might reflect the higher drought tolerance of this species. This work highlights the potentially intersecting, short-term physiological and pollinator behavioural responses to drought and suggests that such responses might reshape plant–pollinator interactions, ultimately reducing reproductive output for less drought-tolerant wildflowers. [ABSTRACT FROM AUTHOR]

Background and Aims Floral characteristics vary significantly among plant species, and multiple underlying factors govern this diversity. Although it is widely known that spatial variation in pollinator groups can exert selection on floral traits, the relative contribution of pollinators and climate to the variation of floral traits across large geographical areas remains a little-studied area. Besides furthering our conceptual understanding of these processes, gaining insight into the topic is also of conservation relevance: understanding how climate might drive variation in floral traits can serve to protect plant–pollinator interactions in globally change conditions. Methods We used Rhododendron as a model system and collected floral traits (corolla length, nectar volume and concentrations), floral visitors and climatic data on 21 Rhododendron species across two continents (North America, Appalachians and Asia, Himalaya). Based on this, we quantified the influence of climate and pollinators on floral traits using phylogeny-informed analyses. Key Results Our results indicate that there is substantial variation in pollinators and morphological traits across Rhododendron species and continents. We came across four pollinator groups: birds, bees, butterflies and flies. Asian species were commonly visited by birds, bees and flies, whereas bees and butterflies were the most common visitors of North American species. The visitor identity explained nectar trait variation, with flowers visited by birds presenting higher volumes of dilute nectar and those visited by insects producing concentrated nectar. Nectar concentration and corolla length exhibited a strong phylogenetic signal across the analysed set of species. We also found that nectar trait variation in the Himalayas could also be explained by climate, which presented significant interactions with pollinator identity. Conclusions Our results indicate that both pollinators and climate contribute and interact to drive nectar trait variation, suggesting that both can affect pollination interactions and floral (and plant) evolution individually and in interaction with each other. [ABSTRACT FROM AUTHOR]

The genus Aquilegia has provided a useful model system for the study of pollination biology, reproductive ecology and evolution, and floral development. In particular, the evolution of nectar spurs is hypothesized to have promoted a rapid radiation in the genus. Here, we review published studies pertaining to the reproductive biology of 30 of the ca. 130 species of Aquilegia and summarize patterns of autogamy, herkogamy, dichogamy, pollination systems, and floral syndromes across species. We also present detailed descriptions of the reproductive ecology for each of the 30 species (appendix). All tested species of Aquilegia are self-compatible. Dichogamy and herkogamy patterns differ among species and are poorly understood because of a lack of data about stigma function. The majority of Eurasian species studied are pollinated by nectar- and pollen-collecting bumblebees and/or bees, with four species pollinated by syrphid flies. The European A. paui seems to be mainly autogamous. In North America, pollination by hummingbirds or hawkmoths is frequently associated with secondary pollination by pollen- and/or nectar-collecting bees, whose effectiveness is unclear. Pollinator shifts are accompanied by changes in floral traits, including spur length, floral color, and flower orientation. Future research should focus on describing stigma development, morphology, and receptivity, which is needed in most species to document the duration and possible overlap of male and female flowering stages. Additional pollination studies are needed, including quantification of the relative performance of Aquilegia pollinators. Detailed studies of pollen transfer and outcrossing rates have been done only for a few species but would greatly help to define whether systems are mixed or specialized and to understand further selective mechanisms involved in the evolution of floral traits and the radiation of the genus. [ABSTRACT FROM AUTHOR]

Simple Summary: It is well documented in the literature that bees have been facing numerous stressors in recent decades. Although honey bees are well managed worldwide, they have not been unaffected by these challenges. Honey bees are important for pollination in various crops, for the beekeeping sector and for the natural habitats as well. However, to perform this role effectively, they require proper nutrition to support their healthy growth and that of the colony. In the current review, we broadly discuss the basic nutritional needs of honey bees, such as the consumption of proteins, carbohydrates, lipids, amino acids, vitamins, minerals, water, and other essential components. Additionally, we also discuss the use of nutritional supplements aimed at supporting the health and strengthening of the colony, and how, despite these efforts, inadequate nutrition can still be a problem for honey bee colonies. Honey bees are known for their wide global distribution, their ease of handling, and their economic and ecological value. However, they are often exposed to a wide variety of stress factors. Therefore, it is essential for beekeepers to maintain healthy bee colonies. In this context, a balanced diet is recommended to support the growth of strong and healthy honey bee colonies. The purpose of this review is therefore to provide an overview of the nutritional requirements of Apis mellifera and their importance for the maintenance of healthy bee colonies. An adequate diet includes the consumption of sufficient amounts of proteins, carbohydrates, lipids, amino acids, vitamins, minerals, water, and essential sterols, and a diet based on multi-floral pollen is desirable. However, when honey bee colonies are located near agroecosystems with lower resource diversity, both brood rearing and colony longevity may decrease, making them more susceptible to parasites and diseases. On the other hand, efforts have been made to improve the health of honey bee colonies with the help of nutritional supplements consisting of a variety of components. Nevertheless, studies have shown that even with these supplements, a lack of nutrients can still be an issue for honey bee colonies. Furthermore, future research should focus on identifying nutritional supplements that can better replicate natural diet diversity and assessing long-term effects on honey bee colony resilience, especially in low-flowering areas. This review discusses the interaction between nutrient requirements and the effects of supplements on colony health. [ABSTRACT FROM AUTHOR]

The article "Pollination by Ants, Camel Crickets, and Cockroaches in a Non-Photosynthetic Plant" explores the pollination biology of the non-photosynthetic plant Balanophora subcupularis. The study found that camel crickets and cockroaches are effective pollinators due to carrying large quantities of pollen, while ants make a significant collective contribution through frequent visits. The research suggests that these insects play a crucial role in pollinating B. subcupularis, especially in environments where typical pollinators are scarce. [Extracted from the article]

Drought-induced changes in floral traits can disrupt plant–pollinator interactions, influencing pollination and reproductive success. These phenotypic changes likely also affect natural selection on floral traits, yet phenotypic selection studies manipulating drought remain rare. We studied how drought impacts selection to understand the potential evolutionary consequences of drought on floral traits. We used a factorial experiment with potted plants to manipulate both water availability (well-watered and drought) and pollination (open and supplemented). We examined the treatment effects on traits of Brassica rapa and estimated phenotypic selection and whether it was pollinator-mediated in these two abiotic conditions. Drought affected plant phenotypes, leading to plants with fewer flowers and ultimately lower seed production. Flowering time did not show variation with watering, but we found the strongest effect of drought on selection was for flowering time. There was a selection for flowering faster in drought but not well-watered conditions. Pollinators instead were the agents responsible for selection on flower size, but we did not find strong evidence that drought effected pollinator-mediated selection. There was a stronger selection for larger flowers in drought compared to well-watered plants, and it could be attributed to pollinators however, there was no significant difference between watering treatments. Our results show the effects of drought are not limited to phenotypic responses and may alter evolution in plants by changing phenotypic selection on traits. The connection between phenotypic plasticity and selection may be important to understand as we found the most variable trait (display size) was not under selection while the trait with different selection in drought (flowering time) did not change in response to drought. Our study highlights the importance of manipulating potential agents of selection, especially to understand fully the potential impacts of components of climate change such as drought. [ABSTRACT FROM AUTHOR]

Microbes found in nectar and dispersed by animal visitors can mediate pollination and host fitness. While previous studies have characterised floral nectar microbiomes and their effects on invertebrate pollinators, fewer studies have focused on vertebrate pollinators, especially outside of the Northern Hemisphere. In Aotearoa New Zealand, vertebrates, such as birds and bats, are critical pollinators for many native plant species. Here, we present nectar microbiome profiles for two endemic, vertebrate-pollinated plant species in Aotearoa New Zealand, wharariki, mountain flax (Phormium cookianum), and pua o te Rēinga, wood rose (Dactylanthus taylorii). We used vertebrate exclusion treatments and camera traps to monitor visitation. Camera trap footage revealed silvereye (Zosterops lateralis), ship rat (Rattus rattus), and possum (Trichosurus vulpecula) visitation. We detected shifts in microbial species turnover in wood rose and varying relative abundances of fungal and bacterial taxa across the vertebrate exclusion treatments for both mountain flax and wood rose. However, we did not detect strong effects on floral nectar microbiome community composition or richness. Future work should move beyond profiling the microbial communities and identify fitness consequences and pollination outcomes, which could affect conservation and management decisions. [ABSTRACT FROM AUTHOR]

Summary An emerging focus of research at the intersection of botany, zoology, and microbiology is the study of floral nectar as a microbial habitat, referred to as the nectar microbiome, which can alter plant–pollinator interactions. Studies on these microbial communities have primarily focused on yeasts, and it was only about a decade ago that bacteria began to be studied as widespread inhabitants of floral nectar. This review aims to give an overview of the current knowledge on nectar bacteria, with emphasis on evolutionary origin, dispersal mode, effects on nectar chemistry and plant–animal interactions, community assembly, agricultural applications, and their use as model systems in ecological research. We further outline gaps in our understanding of the ecological significance of these microorganisms, their response to environmental changes, and the potential cascading effects. [ABSTRACT FROM AUTHOR]

Summary Pollination syndromes are a key component of flowering plant diversification, prompting questions about the architecture of single traits and genetic coordination among traits. Here, we investigate the genetics of extreme floral divergence between naturally hybridizing monkeyflowers, Mimulus parishii (self‐pollinated) and M. cardinalis (hummingbird‐pollinated). We mapped quantitative trait loci (QTLs) for 18 pigment, pollinator reward/handling, and dimensional traits in parallel sets of F2 hybrids plus recombinant inbred lines and generated nearly isogenic lines (NILs) for two dimensional traits, pistil length and corolla size. Our multi‐population approach revealed a highly polygenic basis (n = 190 QTLs total) for pollination syndrome divergence, capturing minor QTLs even for pigment traits with leading major loci. There was significant QTL overlap within pigment and dimensional categories. Nectar volume QTLs clustered with those for floral dimensions, suggesting a partially shared module. The NILs refined two pistil length QTLs, only one of which has tightly correlated effects on other dimensional traits. An overall polygenic architecture of floral divergence is partially coordinated by genetic modules formed by linkage (pigments) and likely pleiotropy (dimensions plus nectar). This work illuminates pollinator syndrome diversification in a model radiation and generates a robust framework for molecular and ecological genomics. [ABSTRACT FROM AUTHOR]

Temporal activity patterns of animals can indicate how individuals respond to changing conditions. Gregarious roosting bats provide an opportunity to compare activity patterns among individuals living in the same location to investigate how reproductive status or sex may influence activity budgets. We examined how the activity patterns of the nectarivorous bat Leptonycteris yerbabuenae vary depending on reproductive conditions, sex, and environmental conditions. We analyzed 5 years of individual mark-resighting data using daily detections of L. yerbabuenae marked with passive integrated transponder tags (PIT-tags) at 3 subterranean roosts on the Baja California Peninsula, Mexico. We derived 4 metrics using PIT-tag detections at roost entrances to calculate periods inside the roost and time spent outside the roost (time of emergence, returns to the roost, hours inside the roost, and hours of activity). We found differences among pregnant, lactating, and nonreproductive females for roost returns, hours inside the roost, and hours of activity outside the roost. Lactating females spent the longest time outside the roost, suggesting that the energetic demands of lactation require longer foraging bouts. Contrary to our expectations, lactating females had the fewest returns to the roost during the night, suggesting that lactating females did not shorten foraging bouts to return to nurse pups. Activity patterns differed between females and males and among seasons associated with different food availability. Females had fewer returns during the night and spent more time outside the roost than males. The time of emergence for males was earlier than for females except during the nectar season when most females are reproductively active. Differences in activity patterns among reproductive status, sex, and environmental conditions show how individuals modify behaviors to meet their energetic demands. We demonstrate how mark-resighting data from PIT-tag systems at roost entrances can be used to compare activity patterns of gregarious roosting bats. [ABSTRACT FROM AUTHOR]

Honey production by stingless bees is closely related to the foraging activities of worker bees, particularly nectar foraging. The urgency of this study stems from the community's need for adequate understanding and information on honey production which can vary due to various factors, such as forage and season. The purpose of this study was to determine the extent to which foraging activity affects the amount of honey produced by T. laeviceps during the rainy and dry seasons. The focal sampling method was used to observe foraging behaviour and the acetolysis method was used to observe pollen. The abiotic factors were measured through direct observation. Honey production was observed as a result of foraging behaviour and variations in abiotic factors. In SPSS v27 software, data from foraging behaviour observations were analysed using one-way ANOVA followed by Tukey's test with 95% confidence level and interpreted in tables and figures. Multiple linear regressions and Pearson's correlations were used to test the relationship between abiotic variables and bee return to hive behaviour. All honey volume data were collected, averaged, and evaluated using bar charts. Based on these results, the amount of honey produced by T. laeviceps in the dry season was significantly higher than that produced during the wet season. This was because the number of bees actively foraging was also higher in the dry season (June-August) which was strongly influenced by temperature and light intensity (p > 0.05). In addition, the number of flowering plants available for harvest during the dry season was higher than that during the rainy season. The results of this study can be used as a reference by beekeepers to determine the appropriate time to harvest honey. Information on the types of forage plants identified in this study can provide information on bee preferences in making choices related to forage plants. [ABSTRACT FROM AUTHOR]

Exposure to pesticides is one potential factor contributing to the recent loss of pollinators and pollinator diversity. Few studies have specifically focused on the relationship between pesticide management during ornamental plant production and contamination of nectar. We evaluated contamination of nectar in Salvia 'Indigo Spires' (Salvia longispicata M. Martens & Galeotti × S. farinacea Benth.) associated with applications of the systemic insecticide thiamethoxam, and the nonsystemic fungicides boscalid and pyraclostrobin. Applications were made at the labeled rates for the commercially available products, and we compared the influence of application method (drench vs. spray), timing (relative to flowering), and rate (low vs. high) for each pesticide. Nectar was sampled using 50‐µL microcapillary tubes and analyzed by liquid chromatography–tandem mass spectrometry. The results indicate that concentrations from the spray application resulted in the least contamination of nectar with the systemic thiamethoxam, with lower concentrations occurring when thiamethoxam was applied before blooming at the lowest rate. Concentrations of thiamethoxam and its metabolite clothianidin were detected in nectar in all treatments (regardless of the method, timing, or rate of application), and ranged from 3.6 ± 0.5 ng/mL (spray‐applied before blooming, low rate) to 1720.0 ± 80.9 ng/mL (drench‐applied after blooming, high rate). Residues of clothianidin in nectar ranged from below quantification limits (spray‐applied before blooming, low rate) to 81.2 ± 4.6 ng/mL (drench‐applied after blooming, high rate). Drench applications resulted in the highest levels of nectar contamination with thiamethoxam, and exceeded published median lethal concentrations (LC50s/median lethal doses for native bees and/or honeybees in all cases). Spray treatments resulted in nectar concentrations exceeding published LC50s for some bee species. In comparison, all nonsystemic treatments resulted in concentrations much lower than the published no‐observable‐effect doses and sublethal toxicity values, indicating low risks of toxicity. Environ Toxicol Chem 2024;43:2616–2627. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Lambda-cyhalothrin is the most widely used insecticide worldwide. This study investigates the impact of lambda-cyhalothrin on honeybees (Apis mellifera) colonies under semi-field and field conditions utilizing the formulated product (Karate 5% at a concentration of 0.85 ml/l). Considering the application of lambda-cyhalothrin in onion fields, the foraging activities reduced by 27.89 and 29.28% under semi-field and field conditions, respectively. The number of dead workers in the comparison group was three-fold higher than that in the control group under both semi-field and field conditions. Under semi-field and field conditions, reductions were observed in the brood (22.6 and 24.01%), pollen (94.46 and 41.51%), and nectar (69.27 and 44.50%) areas. The effect of lambda-cyhalothrin on the strength of A. mellifera under semi-field conditions resulted in a significant decrease until the 14th day (2.20 bee frames/hive) and in field condition it was on the 7th day (4.79 bee frames/hive). This highlights the non-bee-safe nature of lambda-cyhalothrin when applied during flowering, and spraying should be avoided to reduce its contamination of nectar and pollen. Overall, our results show the significance of conducting field trials to accurately assess the risk of pesticides, depicting a more realistic exposure scenario under actual colony conditions. [ABSTRACT FROM AUTHOR]

The article explores the nectar foraging behavior of Ethiopian wolves on Kniphofia foliosa flowers in the Bale Mountains of southern Ethiopia. Observations suggest that wolves may contribute to the pollination of these flowers by transferring pollen while foraging for nectar. This behavior raises questions about the wolves' role as pollinators and their significance in the plant-pollinator interaction. The study highlights the need for further research to understand the wolves' impact on the plant population and the co-evolution between wolves and the plants. [Extracted from the article]

Simple Summary: This study examines the relationship between a parasitic plant and its host, focusing on how nectar composition affects insect visitors. It was found that an infected plant attracted fewer insects compared to its uninfected counterparts, likely due to less appealing nectar. Its nectar contained various compounds that might repel insects, suggesting a defense mechanism. The findings indicate that while some parasitic plants do not rely on pollinators, they still produce abundant nectar, mainly consumed by ants. This research is significant as it reveals how these plants may affect their host's growth and nutrient uptake, potentially offering insights into the development of natural insect repellents. Such plant-based solutions could benefit agriculture and reduce reliance on chemical pesticides, promoting a healthier environment. Salvia absconditiflora and Orobanche anatolica exhibit a parasitic relationship. S. absconditiflora serves as a rich food resource for insects due to its abundant nectar. O. anatolica demonstrates host specificity towards S. absconditiflora. The objective of this study is to assess potential variations in entomofauna dynamics and nectar chemistry attributable to parasitism. The observational groups consisted of S. absconditiflora individuals infected and uninfected by O. anatolica, as well as O. anatolica individuals. Entomofauna was monitored during the flowering periods of target species. The collected data were analyzed using biodiversity indexes. The nectar of the plant groups was evaluated with LC-QTOF-MS analysis to identify possible repellents for insects. S. absconditiflora plants free from infection had significantly higher insect diversity and abundance compared to those infected by O. anatolica. Parasitism by O. anatolica appeared to modify the entomofauna dynamics of S. absconditiflora, as demonstrated by the disparities in insect diversity metrics between infected and uninfected plants. When comparing the nectars of the plant groups, it was determined that the nectar from the parasitic plant and the infected S. absconditiflora contained substances with repellent properties in higher quantities than that of uninfected S. absconditiflora, including thymol, n-benzyloleamide, azadirachtin, capsaicin, azatadine maleate, and andrachcinidine. This study concluded that parasitism could lead to differences in entomofauna associated with these species. [ABSTRACT FROM AUTHOR]

BACKGROUND: 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. RESULTS: 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. CONCLUSION: 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]

Organisms with complex life cycles undergo ecological transitions between life stages, often resulting in stage-specific resource use. The relative contribution of each stage-specific resource to vital rates influences population dynamics and subsequently whether habitats can support viable populations. In lepidopterans, survival to reproduction requires sufficient resources for immature life stages, but the extent to which resources for adults are critical to population persistence is variable. We studied Boisduval's blue butterflies (Icaricia icarioides), in a greenhouse experiment, to quantify the effect of the adult diet, nectar, on vital rates. Butterflies fed ad libitum produced 3.4 times more eggs, on average, over their lifetime and lived 6 more days relative to those which only had access to water. We used these experimental data to parameterize a population model to test if vital rates with and without nectar result in viable population growth rates. Despite individual females laying 68 eggs without nectar, we found that Boisduval's blue butterfly populations will not persist without the improved fecundity associated with nectar resources (λ < 1). In this species, although amino acids in the adult diet contributed to various improvements in fecundity, these improvements did not translate to improvements in population growth rates. Incorporating our experimental vital rates into a population model indicates that the relative abundance and quality of nectar can alter at what threshold other resource(s) are limiting the population. [ABSTRACT FROM AUTHOR]

Bees are the primary consumers of pollen in many ecosystems, but pollen consumption by adult bees while foraging is rarely studied, leaving a gap in our understanding of the nutritional ecology of collective foraging and pollination biology more generally. For example, while eusocial bees feed upon pollen from colony stores, whether they also consume pollen directly from flowers to meet their own needs or to assess its quality for the broader collective is unknown. We therefore captured wild bumble bee colonies (Bombus bimaculatus and Bombus griseocollis) and tested whether individual workers consumed pollen directly from flowers in a lab-based foraging assay. After confirming the presence of floral pollen in worker crops (i.e., consumption at flowers), in a field setting, we tested alternative hypotheses for the function of this behavior using information about the composition, abundance, and diversity of pollen found in the crops vs. pollen baskets of three species of pollen- and nectar-foraging bumble bees (Bombus bimaculatus, B. griseocollis, and B. impatiens). Consistent with the hypothesis that consuming pollen at flowers reflects sampling, total pollen quantity in crops was consistently smaller than in pollen baskets, and basket pollen tended to be a subset of that found in crops. Further, pollen foragers consumed more and different kinds of pollen than nectar foragers. Pollen consumption at flowers is thus unlikely to be purely incidental or to substantially benefit workers nutritionally. Instead, consuming pollen directly from flowers likely allows foragers to quickly assess pollen quality before collecting it to feed the colony as a whole. [ABSTRACT FROM AUTHOR]

In bee diets, nectar is the primary source of carbohydrates. During scarcity of bee flora, such as in winter, beekeepers typically provide supplemental sugar syrup as a nectar substitute. We examined four types of sugars (sucrose, fructose, glucose, and a mixture of fructose and glucose) on bee longevity, bee appetitive, and their impact on pollen digestion. The results showed that sucrose and glucose had extended the longevity in cages. Bees preferred sucrose at a 50% concentration since they consumed more than the other sugar types in cages and in the multiple-choice test experiment in apiary. Bees given sucrose solution consumed the most pollen. In contrast, the cages provided the fructose solution consumed the least amount of pollen, increasing body fat percentage, which can be considered evidence of a digestive disorder. Generally, the type of sugar affects bee's benefits from nutrition. Finally, sucrose is the best type of sugar and is considered the ideal substitute for nectar. [ABSTRACT FROM AUTHOR]

The nectar microbiome can influence pollinator choice and plant fitness. Previous research has shown that changes in environmental conditions at large spatial scales can influence nectar microbiome composition. However, little is known about how changes in climate with increasing elevation affect nectar microbiome abundance and composition. Here, we describe the culturable nectar mycobiome (CNMB) of Rhododendron catawbiense (Ericaceae) by quantifying colony abundance, identity and richness of fungal genera. We further evaluate how the CNMB abundance, diversity and composition (i.e. the fungal species within the nectar microbiome) varies at two different elevations. Nectar samples were collected from R. catawbiense individuals at a high and low elevation and were cultured on yeast agar with 0.01% chloramphenicol media. Fungal colonies were categorized morphologically, quantified and then identified using DNA barcoding. In total, 2822 fungal colonies were recorded belonging to six genera across both elevations. Elevation did not influence CNMB diversity (Simpson's diversity index) or genera richness per flower, however only three genera were found at the high elevation while six were found at the low elevation. Elevation had a significant effect on colony abundance with a 95% increase in the number of colonies in nectar samples at low compared with the high elevation. Variation in abundance and the overall genera composition of fungal colonies across elevations may have the potential to affect nectar quantity and quality and ultimately pollination success. This study adds to our understanding of the drivers of CNMB composition across spatial scales and its potential implications for plant–pollinator interactions. [ABSTRACT FROM AUTHOR]

In 2020, Mexico's Congress mandated front-of-package warning labels (FOPWL) and two cautionary legends; one of which for non-nutritive sweeteners (NNS) with a statement "Contains NNS. Avoid in children". The aim of the study was to assess the influence of the "excess in sugar" warning label (WL) and NNS cautionary legend on preference and healthfulness perception of fruit-based beverages among parents of 5–10 year-olds. Also, to test if parents' preferences and perceptions differed by nutrition knowledge and previous knowledge on NNS. Data from the EPHA niñ@s (Study of the Perception and Dietary Habits in Children, for its acronym in Spanish) cohort were analyzed (n = 844). Parents were asked to choose between 100% juice and nectar with added sugars above the cut-off point, and between the latter and nectar with NNS marketed as "light", and to rate how healthy they considered each product at two different timepoints. At time 1, products were shown without the FOPWL; at time 2, nectar with excess sugar had the "excess sugar" WL and nectar with NNS had the cautionary legend on NNS. General Linearized Models (GLM) were used to assess changes in preference and perceived healthiness. Interaction terms assessed the impact of nutrition knowledge and NNS awareness. The study found that FOPWL significantly shifted parental preferences towards 100% juice over nectar with "excess sugar" (15.4% increase, p<0.001), and the latter over nectar with NNS (21.8% increase, p<0.001). Similarly, the FOPWL decreased the perceived healthiness of both nectar with "excess sugars" and nectar with NNS. The effect of labels on healthfulness perception was strongest among parents with low to medium nutrition knowledge and no prior knowledge of NNS. The inclusion of FOPWL seems to aid parents in making better-informed decisions regarding the nutritional quality of beverages for their children. [ABSTRACT FROM AUTHOR]

Flowering plants can be introduced in modern agroecosystems to support resident natural enemies in the context of Conservation Biological Control (CBC). Buckwheat (Fagopyrum esculentum) (Polygonales: Polygonaceae) has been shown to enhance the longevity of several parasitoids through the provision of high quality and easily accessible floral nectar. Yet floral nectar is ubiquitously colonized by microbes which can change nectar chemistry with consequences for parasitoids. Nonetheless, how bacteria associated with buckwheat floral nectar affect parasitoid performance is not known. In this study, adult females of Trissolcus basalis (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), two parasitoids of Nezara viridula (Hemiptera: Pentatomidae), were provided with synthetic nectar fermented by 14 bacterial isolates originating from buckwheat nectar. We recorded the effect of bacterial fermentation on female longevity and nectar chemistry. In the case of T. basalis, females consuming nectar fermented by Bacillus sp., Brevibacillus sp., Brevibacterium frigoritolerans, Saccharibacillus endophyticus, and Terribacillus saccharophilus significantly enhanced their longevity compared with females fed with non‐fermented nectar. For O. telenomicida, enhanced longevity was recorded only in the case of B. frigoritolerans and Pantoea dispersa. For both parasitoids, no negative effects due to bacterial fermentation of nectar were recorded. Chemical investigations of bacteria‐fermented nectars revealed an increased diversity in the composition of sugars and sugar alcohols, whereas non‐fermented nectar only contained sucrose. Our findings show that nectar‐inhabiting bacteria are important “hidden players” in the interactions between flowers and parasitoids, an indication that a better understanding of plant–microbe–insect interactions could improve CBC programmes. [ABSTRACT FROM AUTHOR]

Flowering plants produce pollinator rewards such as nectar and pollen, whose quantity and quality usually depend on the whole-plant state under specific environmental conditions. Increasing aridity and temperature linked to climate change may force plants to allocate fewer resources to these traits, potentially disrupting plant-pollinator interactions. In this study, for the first time, both quantitative review (vote-counting procedure) and meta-analytic approach were used to assess the implications of increased temperatures linked to global warming on floral rewards, including nectar (sugar concentration, content, and volume) and pollen (germination and viability), as well as on pollinator visits. Furthermore, we explored whether observed effects of warming are related either to temperature range, plant type (wild vs crop), or study approach (greenhouse vs field experiments). We also assessed the correlations between elevated temperatures and the characteristics that were affected by the temperature range. The results of the vote-counting technique showed that higher temperatures led to a decrease in floral rewards but did not affect the number of pollinator visits. Concurrently, meta-analysis detected adverse effects of warming on pollen germination and viability. Warming effects depended on the plant type for pollen germination and viability, on study approach for nectar sugar concentration and pollen germination, and on temperature range for pollen germination and pollinator visits. Additionally, we found that pollen germination and pollinator visits significantly decreased as temperature range increased. Our results showed that global warming affects floral rewards in both wild and crop plants, providing insights into the effects of changing climatic conditions on plant-pollinator interactions and pollination services. [ABSTRACT FROM AUTHOR]

The aim of the present study is to evaluate the egg-laying dynamics of queen bees in Roger-Delon and Warre hives located in an apiary at an altitude of less than 1000 m. The study was conducted during the active season of 2023, in an apiary located at an altitude of 860 m in south-western Bulgaria, Pernik district. The bee colonies were balanced before the beginning of the experiment. Two groups of 6 colonies were formed from each Roger-Delon and Warre system. Sealed worker brood was measured until the appearance of constant nectar flow (April – June), and after the appearance of constant nectar flow (September – November). There is currently a need to examine and quantify the egg-laying dynamics of queens in new hive systems. Queen egg-laying activity is affected by a variety of seasonal, nutritional and social factors. According to the results obtained, the average sealed worker brood in Warre hives and Roger-Delon hives are 10484±1031 cm² and 9564±1057 cm² (mean±SD) respectively, for the whole period until appearance of constant nectar flow. [ABSTRACT FROM AUTHOR]

Over a century of research on pollinator cognition has shown that pollinators such as bees perceive and learn a multitude of floral stimuli and are capable of sophisticated decision-making using a variety of cognitive abilities. Research on pollinator cognition usually focuses on a single reward aspect in isolation, which does not reflect the complexity of reward types, chemistries, and attributes many pollinators encounter while foraging. Reward complexity can impact pollinators' perception, learning, and decision-making in interesting and sometimes unexpected ways. A cognitive perspective can shed new insight into the functions of floral reward complexity and bridge the fields of animal behavior and plant ecology. The cognitive ecology of pollination is most often studied using simple rewards, yet flowers often contain multiple types of chemically complex rewards, each varying along multiple dimensions of quality. In this review we highlight ways in which reward complexity can impact pollinator cognition, demonstrating the need to consider ecologically realistic rewards to fully understand plant–pollinator interactions. We show that pollinators' reward preferences can be modulated by reward chemistry and the collection of multiple reward types. We also discuss how reward complexity can mediate pollinator learning through a variety of mechanisms, both with and without reward preference being altered. Finally, we show how an understanding of decision-making strategies is necessary to predict how pollinators' evaluation of reward options depends on the other options available. [ABSTRACT FROM AUTHOR]

This paper presents a new hybrid algorithm based on artificial bee colony (ABC) and chaotic search strategy (CSS), known as ABC-CSS to solve the harmonic estimation problems in the case of time varying acceleration response signal. The ABC algorithm simulates the intelligent behavior of bees in nature to find high-quality nectar sources according to different divisions of labor. Aiming at the lack of diversity, poor global and local search ability, as well as slow convergence speed of ABC, an improved ABC based on CSS is proposed. The algorithm generates new neighborhood points by the transformation of chaotic and decision variables by carrier mapping, which provides a broader search space and better location of nectar sources for bees and recruited observation bees, and enhances the diversity of bee colonies. At the same time, the investigation of a local honey bee search better solves the algorithm problem of the local minimum and improves the convergence property of the ABC. Simulation and experimental studies are conducted to validate the superiority of the proposed ABC-CSS in harmonic estimation. [ABSTRACT FROM AUTHOR]

Backround: This study was carried out to determine the nutritional value and methane production potential of Phacelia tanacetifolia plant in different growth stages in April-May year in the ecological conditions of the province of Adıyaman in Turkey. Methods: Phacelia (Phacelia tanacetifolia) plant samples were collected with four replications in four different stages, preflowering, early flowering, mid-flowering and end of flowering (seeding). The nutrients of the feed samples were determined. The gas production was measured after 24 hours of incubation of the forage with rumen fluid. Result: The effect of harvest time on chemical composition was highly significant. In vitro gas production was lowest in stage I. and highest in II. The methane (CH4) lowest production values were found in the 1st stage, whereas the highest value was observed in the 4th stage (seed-binding stage), where the difference was statistically significant. ME was 7.49, 9.54, 8.90 and 8.61 MJ/kg DM respectively and the difference between the stages was statistically significant. It was concluded that Phacelia tanacetifolia, which is known as an important nectar source in the world and in Turkey. It is appropriate to harvest the phacelia plants in the second stage, i.e., at early flowering for higher ME contents and OMD. [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. See also the Commentary on this article by Buchmann & Papaj, 244: 746–748. [ABSTRACT FROM AUTHOR]

Introduction: Gradual pollen presentation is a reproductive strategy for plants to improve the efficiency and accuracy of pollen export and acceptance as well as to promote outcrossing. Vaccinium corymbosum Berkeley has a typical mechanism of gradual pollen presentation. Methods: In this study, we used indoor and outdoor observations to investigate the floral characteristics, pollination characteristics and breeding system of this species in open ground and greenhouse. Results: The results showed that the single white, inverted bell-shaped flower of V. corymbosum was able to effectively avoid the negative effects of rainfall, nectar dilution and pollen removal by wind, and improved pollen viability and the duration of stigma receptivity. The setting rate of 'Northland' is higher than open ground by artificial pollination in greenhouse, therefore, greenhouses are more suitable for 'Northland' reproduction. The gradual pollen presentation prolongs dispersal time, promotes pollinator participation in the pollination process, increases staminate fitness, and provides for nectar feeding by pollinators as well as pollen export. Bombus spp. and A. m. ligustica were effective pollinators in the open ground and greenhouse, and the pollination efficiency of Bombus spp. was higher than that of A. m. ligustica, and greenhouse pollination is more efficient than open ground. The coincidence of the peak period of pollinator visits with the period of highest pollen viability and optimal pollination of stigmas, as well as the high nectar production, could maximize the frequency of pollinator visits and increase the chances of successful pollination as well as the pollination efficiency. Discussion: Therefore, it is important to study the floral characteristics of V. corymbosum Berkeley and the mechanism of gradual pollen presentation in order to improve the pollination efficiency and promote the success of outcrossing, which can provide a theoretical basis for the breeding of V. corymbosum. [ABSTRACT FROM AUTHOR]

Volatile compounds in floral nectar may affect plant–pollinator relationships; however, the understanding of the distribution and functions of scented floral nectar is still relatively limited. In this study, we examined the volatile constituents of the scented floral nectar of the black lily Fritillaria camtschatcensis and their potential to attract flower‐visiting flies. In Japan, F. camtschatcensis comprises two varieties, var. camtschatcensis (lowland) and var. keisukei (alpine). The flowers of both varieties secrete large amounts of nectar that is fed on by visiting flies. We investigated the sugar concentration of the nectar using high‐performance liquid chromatography (HPLC) and studied its volatile chemical composition using gas chromatography–mass spectrometry. We conducted a bioassay using a synthetic mixture of nectar volatiles of the lowland variety to test whether flies are attracted to volatile compounds in the nectar scent. HPLC analysis showed that glucose and fructose occur in the nectar of the alpine variety, whereas the lowland variety nectar contained glucose but lacked fructose. Nectar volatile compounds differed substantially between the two varieties; the volatiles of the lowland variety consisted primarily of four aliphatic acids, whereas acetophenone was the main volatile compound in the alpine variety. The bioassay showed that a mixture of three aliphatic acids detected as volatiles of the lowland variety nectar attracts flies, including those that visit the alpine variety flowers such as Calliphoridae. These results suggest that the volatiles of the scented nectar serve as attractants for flower visitors and may have an important role in the pollination of F. camtschatcensis. [ABSTRACT FROM AUTHOR]

Competition for nectar is expected to result in feeding niche differentiation. Here, we targeted the sexually size-dimorphic Volcano Sunbird (Cinnyris preussi) on Mount Cameroon. We investigated whether males and females feed on different plant species, whether females with shorter bills than males prefer shorter flowers, and whether larger dominant males visit more energetic flowers that produce higher amounts of nectar sugars. We also asked whether feeding niches were spatially separated along the elevation gradient and whether this separation varied between the two contrasting seasons. We collected data on the frequency of visits to individual plant species and analyzed the male-to-female ratios in the mist-netted dataset. In addition, we estimated production of nectar sugar in individual habitats and seasons. Despite the large dataset collected, encompassing 6476 bird–plant interactions, our findings did not provide evidence of differences in the spectra of the visited plant species. In addition, females did not visit flowers with shorter tubes, nor did males visit flowers that produced higher amounts of sugars. However, we observed a sex-specific dispersion of sunbirds during the wet season. During the dry breeding season, both males and females feed mainly in nectar-rich montane and submontane forests. In the wet season, the production of nectar sugar in these habitats decreased dramatically, and females largely disappeared. In contrast, female activity increased in the lowest and highest parts of the altitudinal range. Our findings on elevational movements are important in the current context, in which species face potential threats from habitat destruction and climate change. [ABSTRACT FROM AUTHOR]

Background: Many cross pollinated flowering plants rely on pollinators for reproduction and survival. The pigeon pea (arhar), Cajanus cajan L., is the India's most important pulse crop. It attracts pollinators because to its cross pollination nature, possible nectar and pollen source, attractive colour and scent of the seeds and timing of blossoming. As a result, a complete research of pigeon pea insect pollinator fauna shall be used to conserve those fauna for increasing pigeon pea pollination effectiveness. Methods: Diversity of different pollinating agents associated with the crop pigeon pea by observing their abundance, diversity, percentage contribution, dominance status and diversity following the statistical diversity indexes were recorded during Kharif, 2021-22 in the state of Odisha where the insect pollinators' fauna was recorded through fixed plot survey. Result: Megachille lanata (Fabricius) was found to be the most dominant pollinator throughout the flowering period among seven different pollinators of order Hymenoptera. M. lanata and Megachille disjuncta (Fabricius) shown higher foraging activity i.e. 6.02 bees/5 min/m2 and 4.25 bees/5 min/m2 respectively. Subdominant class represented maximum species among different dominant status classes exhibited. Very less diversity was observed throughout the season but still more diversity has been observed at mid flowering stags during 10:00-11:00 AM. [ABSTRACT FROM AUTHOR]

Plants use extrafloral nectaries (EFNs) as indirect defence mechanisms against herbivores. These structures contain nectar that is offered to ants in exchange for their protection. EFNs display pronounced functional variation, but it is unknown how this variation comes together in phenotypes. Here, we characterized the main functional traits of EFNs and investigated the associations among them. This work was conducted at a study site in the Caatinga that hosts 14 species of woody plants. We characterized the following functional traits: EFN type, position, arrangement, size, and reducing-sugar level. We observed a marked degree of trait variation (~30%) that was manifested in species-specific trait combinations, giving rise to an 'ecological spectrum'. At one end were Fabaceae species with large, vascularized EFNs that occur individually on the leaf petiole and/or rachis and that produce high levels of reducing sugars. At the other end were Euphorbiaceae species with small, nonvascularized EFNs that are generally grouped on the leaf blade and that produce low levels of reducing sugars. Despite its limited geographical and phylogenetic scale, this study represents an important first step in describing an ecological spectrum that can inform our understanding of the ecological interactions and evolutionary history of this functionally relevant group of plants. [ABSTRACT FROM AUTHOR]

Petrocodon paradelphinius F.Wen & W.C.Chou, a new species of Gesneriaceae from the limestone area of Guangxi, Southwest China, is described and illustrated here. This new species morphologically resembles P. fangianus (Y.G. Wei) J.M.Li & Yin Z. Wang, but it can be easily distinguished from the latter by having peduncles and pedicels puberulent, corolla outside sparsely puberulent, shorter tube 18-20 mm long, orifice from throat to the interior smooth, without protuberances, and lacks nectar guides. The conservation status of P. paradelphinius can be assessed provisionally as Critically Endangered [CR B2b(ii, v) + C2(a, i)]. [ABSTRACT FROM AUTHOR]

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]

Mosquitoes visit flowers to obtain sugar or other nutrients and therefore possibly serve as major or minor pollinators of some plant species. They also often derive plant nutrients from other sources, such as extrafloral nectaries and honeydew. In a few cases, the plant-mosquito relationship is close, and mosquito pollination has been confirmed. Most plant species visited by mosquitoes, however, appear to depend on multiple means of pollination, particularly other flower-feeding insects. In addition, most mosquito species visit the flowers of many kinds of plants, possibly dispersing pollen in both biologically meaningful and irrelevant ways. This apparent lack of selectivity by both plants and mosquitoes liberates each of them from dependence on an unreliable pollen vehicle or nutrient source. A hypothetical pollinating role for the two top vectors of devastating human-disease pathogens, Anopheles gambiae or Aedes aegypti, relies on indirect evidence. So far, this evidence suggests that their participation in pollen transfer of native, introduced, or beneficial plants is negligible. The few plant species likely to be pollinated by these vectors are mostly invasive, harmful weeds associated with humans. That conclusion draws support from four characteristics of these vectors: (1) the numerous alternative potential pollinators of the flowers they visit; (2) their common use of diverse non-floral sources of nutrients; (3) the females' infrequent sugar feeding and heavy reliance on human blood for energy; and (4) their relatively low population densities. From these traits it follows that focused suppression or elimination of these two vectors, by whatever means, is highly unlikely to have adverse effects on pollination in endemic biotic communities or on ornamental plants or food crops. [ABSTRACT FROM AUTHOR]

The pollination characteristics and flowering phenology of Calanthe sieboldii were evaluated to elucidate its reproductive characteristics and breeding systems. Field observations and artificial pollination experiments were conducted to study the pollination biology in Xuancheng City, Anhui Province. Meanwhile, gas chromatography–mass spectrometry (GC-MS) was employed to analyze the species' volatile organic compounds (VOCs). Key findings include the following: (1) the flowering period extends from mid-April to mid-May, with a population-level flowering duration of 29 days in 2017, individual plant flowering averaging 20.22 days, and single flower longevity ranging from 12 to 23 days (mean = 19.30 days); (2) the species exhibits deceptive nectar guides devoid of nectar, indicating food-deceptive pollination, with Bombus sp. identified as its primary pollinator; (3) the pollinial–ovule ratio and hybridization index suggest a high level of self-compatibility without autonomous self-pollination, with no significant difference in pollination success between self- and outcross populations; (4) GC-MS analysis identified methyl benzoate and acacia-related compounds as the primary VOCs of C. sieboldii. These findings provide valuable insights into the conservation and sustainable management of orchids, particularly C. sieboldii. [ABSTRACT FROM AUTHOR]

Plant specialized metabolites are species-specific compounds that help plants adapt and survive in constantly changing ecological environments. Nectar contains various specialized metabolites, essential for maintaining nectar homeostasis. In this study, we employed high-performance liquid chromatography (HPLC) to compare the sugar composition between spoilage nectar and natural nectar, with further analysis of variations in color, odor, pH, and hydrogen peroxide (H₂O₂) content. Microbial strains in Camellia reticulata nectar were isolated and identified using the spread plate method coupled with DNA sequencing. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was implemented to characterize metabolite differences between spoilage and natural nectars. Subsequent in vitro experiments were conducted to validate the effects of screened nectar metabolites on the isolated microbial strains. The results showed that some C. reticulata nectar could spoil and deteriorate, which disrupted nectar homeostasis and significantly reduced the pollination efficiency by pollinators. Spoilage nectar had significant differences in color, odor, sugar composition, pH, and H2O2 content compared to natural nectar. The number of microbial species and quantity in spoilage nectar were much higher. The H2O2 content in natural nectar could reach (55.5 ± 1.80) μM, while it was undetectable in spoilage nectar. A total of 15 distinct microbial strains and 364 differential metabolites were isolated and identified from two types of nectar. In vitro experiments demonstrated that H2O2 could inhibit all the bacteria in C. reticulata nectar except Serratia liquefaciens. 12-Methyltetradecanoic Acid inhibited Bacillus subtilis, Curtobacterium flaccumfaciens, and Rothia terrae, and Myristic Acid only inhibited Rothia terrae. The nectar metabolites screened in this study had no effect on the nectar specialist yeast Metschnikowia reukaufii. In conclusion, the findings of this study revealed that C. reticulata nectar regulates the growth of microorganisms through its metabolites to maintain nectar homeostasis and prevent spoilage. This study improves the understanding of the physiological mechanisms of C. reticulata in maintaining nectar homeostasis and provides theoretical support for controlling nectar diseases and sustaining the reproductive fitness of C. reticulata. Future research could focus on further exploring the complex interactions between different metabolites in C. reticulata nectar and a wider range of microorganisms. Moreover, the development of practical applications based on these findings, such as the development of natural preservatives for nectar-related products or the optimization of pollination efficiency in C. reticulata cultivation, could be an important area for future exploration.

Global bee populations are rapidly declining. One way of supporting bee populations is by enhancing urban green spaces with plants attractive to bees. Plant breeding has introduced a high degree of variability in floral traits, which can affect the attractiveness and usefulness of ornamental plants to bees. In this study, we investigated how variations in floral traits, including nectar sugar content, corolla tube depth, flower colour, UV-presence and the number of flowers, affected the attractiveness of 119 cultivars from eight ornamental plant genera (Salvia nemorosa, Gaillardia aristata, Delosperma cooperi, Lavandula angustifolia, Lavandula stoechas, Sedum telephium, Perovskia atriplicifolia and Agastache hybrida) to honeybees and bumblebees. Our results show that differences in bee visitation rate among cultivars were directly related to variation in floral traits. For most plant genera, cultivars of the same species varied significantly in attractiveness. Honeybees and bumblebees generally did not find the same cultivars and plant genera attractive. Nectar sugar content and flower colour were important for cultivar attractiveness to both honeybees and bumblebees, with corolla tube depth also being an important factor for honeybees. We found that flower colour was often related to the favourability of other floral traits that promote more rewarding or easily accessible flowers. However, most cultivars were considered unattractive and only a small number of cultivars were highly attractive to honeybees (6%) and bumblebees (10%). Overall, our study gives valuable insights for plant breeders, emphasising how different floral traits affect the attractiveness of ornamental plants which helps to select for floral traits that result in more attractive ornamental plants for bees.

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.

Both frugivores and nectarivores are potentially exposed to dietary ethanol produced by fermentative yeasts which metabolize sugars. Some nectarivorous mammals exhibit a preference for low-concentration ethanol solutions compared to controls of comparable caloric content, but behavioural responses to ethanol by nectar-feeding birds are unknown. We investigated dietary preference by Anna's Hummingbirds (Calypte anna) for ethanol-enhanced sucrose solutions. Via repeated binary-choice experiments, three adult male hummingbirds were exposed to sucrose solutions containing 0%, 1% or 2% ethanol; rates of volitional nectar consumption were measured over a 3 h interval. Hummingbirds did not discriminate between 0% and 1% ethanol solutions, but exhibited significantly reduced rates of consumption of a 2% ethanol solution. Opportunistic measurements of ethanol concentrations within hummingbird feeders registered values peaking at about 0.05%. Ethanol at low concentrations (i.e. up to 1%) is not aversive to Anna's Hummingbirds and may be characteristic of both natural and anthropogenic nectars upon which they feed. Given high daily amounts of nectar consumption by hummingbirds, chronic physiological exposure to ethanol can thus be substantial, although naturally occurring concentrations within floral nectar are unknown.