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Although diverse wild pollinators contribute to crop pollination, nocturnal pollinators have been largely overlooked. In this study, we focused on buckwheat, which relies on various insect species for pollination. Since buckwheat flowers are believed to close in the evening, earlier studies have exclusively examined the role of diurnal pollinators. However, some buckwheat flowers have been observed opening at night; thus, we can assume that nocturnal insects play a role in buckwheat pollination. Our field observations showed that 80% of buckwheat flowers that opened in the morning remained open at night. The insects visiting buckwheat flowers at night belonged to the moth families of Noctuidae, Crambidae, and Pyralidae. These moths were all found to have buckwheat pollen on their bodies. To quantify the contribution of nocturnal pollinators to seed set, we conducted a pollinator exclusion experiment using the following bagging treatments: no pollinators (bagging for 24 h), only diurnal pollinators (bagging from 18:00 to 06:00), only nocturnal pollinators (bagging from 06:00 to 18:00), and natural pollination (no bagging). The results showed that the seed set decreased in the following order: natural pollination, diurnal pollinators only, nocturnal pollinators only, and no pollinators, with one-fourth of the buckwheat seed sets resulting from nocturnal pollinators. However, the proportion of flowers open at night decreased as the flowering period progress, and the role of nocturnal pollinators appeared to decline over time. Our findings suggests that nocturnal pollinators may complementarily increase buckwheat seed sets, emphasizing the need to investigate overlooked nocturnal pollinators in crop pollination services. [ABSTRACT FROM AUTHOR]

Fire is a major ecological and evolutionary factor promoting biodiversity and maintaining functioning of naturally fire-prone ecosystems. In tropical savannas, plant communities show a set of fire-adapted traits and both flowering and pollination services have the potential to rapidly regenerate after fire, but fire-suppression policies may disrupt this adaptability following potential woody encroachment. Understanding the effects of fire on plant–pollinator interactions are required to advance conservation of biodiversity and ecosystem functioning. We evaluated the dynamics of plant community assemblage, flower availability, composition of flower functional traits associated with attractiveness to pollinators, and activity and diversity of insect pollinator guilds over ten post-fire stand ages along a 14-year chronosequence in a naturally burned region in the Cerrado, a megadiverse savanna in Brazil. We expect to find a high resilience of plant-pollinator communities and a steady decline in the successional recovery as time-since-fire proceeds. Along the post-fire chronosequence, vegetation was dominated by subshrubs with tubular, white, and nectar flowers arranged in inflorescences, while bees were the predominant pollinators. Plant assemblage and flower number showed an initial significant increase but monotonically declined after 7–9 years after fire. Accordingly, pollinator richness and abundance significantly reached highest peaks in interim periods and a steady decline over time. In contrast, the frequency of community-wide plant-life form, flower functional traits, and pollinator diversity remained unaltered over the post-fire chronosequence. We added compelling evidence of a high post-fire resilience of plant-pollinator communities and further understanding of how fire-suppression policies may affect pollination in the Cerrado. [ABSTRACT FROM AUTHOR]

In flowering plants, pollinators contribute to gene flow while they also respond to variation in plant traits together determined by genetic, epigenetic and environmental sources of variation. Consequently, a correlation between abundance and diversity of pollinators and the genetic and epigenetic characteristics of plant populations such as diversity or distinctiveness is expected. However, no study has explored these long‐term dimensions of plant–pollinator interactions. Mediterranean narrow endemics often exhibit unexpectedly high levels of population genetic and epigenetic diversity. We hypothesize that pollinators may contribute to explain this pattern. Specifically, given the higher sensitivity of small, isolated population to gene flow, we expect a stronger association of pollinators with population genetic and epigenetic variability in narrow endemics than in widely distributed congeners. We studied five pairs of congeneric plant species, consisting of one narrow endemic with a restricted distribution and one widespread congener, found in the Sierra de Cazorla mountains (SE Spain). We characterized the pollinators in up to three populations per species to estimate their diversity and visitation rates. Additionally, we calculated the genetic and epigenetic diversity and distinctiveness of each population using AFLP markers and methylation‐sensitive AFLP markers (MSAP), respectively. We assessed the relationship between pollinator diversity and visitation rates. The diversity of pollinators did not vary according to the plant´s distribution range, but visitation rate was higher in widespread species. As predicted, only narrow endemics showed a significant association between pollinators and their population genetic and epigenetic characteristics. Specifically, higher pollinator diversity and visitation rates entailed higher population genetic diversity and lower epigenetic distinctiveness. This work shows the importance of investigating the relationship between pollinator diversity and population genetics and epigenetics to better understand the evolution of plant rarity. [ABSTRACT FROM AUTHOR]

To predict how biodiversity will respond to global change, it is crucial to understand the relative roles of abiotic drivers and biotic interactions in driving associations between the biodiversity of disparate taxa. It is particularly challenging to understand diversity–diversity links across domains and habitats, because data are rarely available for multiple above‐ and below‐ground taxa across multiple sites.Here, we analyse data from a unique biodiversity data set gathered across a variety of oceanic temperate terrestrial habitats in Wales, comprising 300 sites with co‐located soil microbial, plant, bird and pollinator surveys along with climate and soil physicochemical information. Soil groups are analysed using metabarcoding of the 16S, ITS1 and 18S DNA regions, allowing in‐depth characterisation of microbial and soil animal biodiversity.We explore biodiversity relationships along three aspects of community composition: First, we assess correlation between the alpha diversity of different groups. Second, we assess whether biotic turnover between sites is correlated across different groups. Finally, we investigate the co‐occurrence of individual taxa across sites. In each analysis, we assess the contribution of linear or nonlinear environmental effects.We find that a positive correlation between alpha diversity of plants, soil bacteria, soil fungi, soil heterotrophic protists, bees and butterflies is in fact driven by complex nonlinear responses to abiotic drivers. In contrast, environmental variation did not account for positive associations between the diversity of plants and both birds and AM fungi, suggesting a role for biotic interactions.Both the diversity and taxon‐level associations between the differing soil groups remained even after accounting for nonlinear environmental gradients. Above‐ground, spatial factors played larger roles in driving biotic communities, while linear environmental gradients were sufficient to explain many group‐ and taxon‐level relationships.Synthesis. Our results show how nonlinear responses to environmental gradients drive many of the relationships between plant biodiversity and the biodiversity of above‐ and below‐ground biological communities. Our work shows how different aspects of biodiversity might respond nonlinearly to changing environments and identifies cases where management‐induced changes in one community could either influence other taxa or lead to loss of apparent biological associations. [ABSTRACT FROM AUTHOR]

Pollination is one of the important ecosystem services related to sustainable development of human society. However, the population diversity and abundance of wild bees, important pollinators, have been significantly reduced by climate change, agricultural intensification, and landscape transformation. Re-establishment of pollinator habitat by planting nectar-producing plants is an important way to maintain pollination service. In this study, we investigated the status of wild bees and the traits of flowering plants in 22 apple orchards during flowering stage in Changping District, Beijing in 2019. We analyzed the response of wild bee diversity to the flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in apple orchards, aiming to provide guidance for the selection of nectar-producing plants to establish the habitat of wild bees. A total of 3517 wild bees were captured during the apple flowering season, representing 49 species, 13 genera, and 5 families. We identified 21 flowering plants species that shared a similar flowering period with apple, exhibiting a range of 5 colors and 9 inflorescence types. The Shannon diversity index, evenness index, and social bee richness of wild bee community were positively correlated with flowering plant richness. The total wild bee community richness, social bee richness, underground nesting bee richness were positively correlated with the richness of flowering plant color, but Halictidae bee abundance was negatively correlated with the richness of flowering plant color. The Shannon diversity index and evenness index of wild bee community were positively correlated with the richness of inflorescence types. Megachilidae bee richness was negative correlated with the white flower coverage. Megachilidae bee richness, social bee abundance, and ground nesting bee richness were positively correlated with the purple flower coverage. There was no significant correlation between wild bees and flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in other communities of different families, lifestyles and nesting types. Maintaining diverse ground flowering plants with various traits in orchards is important to improve the diversity of wild bees. In particular, increasing the coverage of purple flower during apple flowering period is helpful to promote the diversity of Megachilidae bee, social bees, and ground nesting bees. [ABSTRACT FROM AUTHOR]

Diverse bee communities pollinate fruits and vegetables, and the composition of these communities has been described for many specialty crops in major production regions. However, pollinator communities in landscapes dominated by agronomic crops may differ in species composition and the contribution of wild bees. With over 4 million ha of maize and soybean, Indiana presents a novel landscape to compare pollinator communities among specialty crops that differ in their use of managed bees and bloom phenology, with potential implications for the composition of wild bee communities and their contributions to flower visitation. We sampled pollinator communities with flower observations and pan traps in spring-blooming apples and blueberries and summer-blooming tomatoes and watermelons, allowing us to compare communities between specialty crops with overlapping and distinct bloom times. Apples, blueberries, and watermelons were stocked with honey bees, and watermelons additionally had managed bumble bees. Across two years of sampling, we observed 1,651 flower visits by 13 taxa, collected 1,967 bees, and identified 84 taxa from collected specimens. Apples and blueberries hosted the richest pollinator communities (34 and 51 taxa, respectively) followed by watermelons (22 taxa), and tomatoes (19 taxa). While 70% of flower visits in apples and blueberries were attributed to honey bees, wild bees accounted for 82% and 99% of flower visits in watermelons and tomatoes, respectively. Our results indicate that distinct pollinator communities persist among co-flowering specialty crops in a landscape dominated by maize and soybean production and underscore the contribution of wild bees for specialty crop pollination, particularly in watermelons and tomatoes.

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the September 2022 newsletter includes updates on irrigation removal, self-guided walking tours, pollinators visiting the native wildflowers, an annual tidewater goby (Eucyclogobius newberryi) survey, camera trap wildlife sightings at Whittier Pond, and the next phase of the NCOS project. The feature story focuses on efforts to catalogue the plants of NCOS as herbarium specimens. Community photos include Wilson’s and Orange-crowned Warblers (Cardellina pusilla and Leiothlypis celata), Black Phoebe (Sayornis nigricans), and Blue-eyed Darner (Rhionaeshna multicolor).

Pollination is the most important ecosystem service performed by insect pollinators benefiting more than three quarters of the major crops in the world. Conservation and management of honey bees are an essential part of the sustainable productivity of cross pollinated crops. The present study was conducted to identify the potential pollinator of berseem in Bundelkhand region, which typically represents the subtropical climatic condition. In total, 14 species of insects belonging to seven families of three insect orders were found visiting berseem flowers. The most frequent floral guests were hymenopterans (81 percent) followed by Lepidoptera (13 percent) and Diptera (6 percent) during the winter season of 2017–2018. Apis dorsata was the most dominant floral visitor, whose peak activity was observed between 10.00 AM and 11.00 AM (7.354/m2/10 min). The activities of pollinators were found maximum during the peak flowering stage of berseem. Seeds obtained from open pollinated plots showed a significant increase in yield (383.24 and 491.41 percent) over caged conditions during 2017 and 2018, respectively. [ABSTRACT FROM AUTHOR]

Farmers understand the general importance of pollinators, and through their management of cropped land and non-cropped areas on the farm they have the potential to do more than any other group to help provide habitat and food for pollinating insects. Pollinators are a continually topical issue for the media and policymakers, and against this challenging background it is not always clear what the best approaches are for farmers or land managers to take to protect and increase pollinators. What do we know about the state of pollinator populations on farmland in the UK? To what extent can the use of agri-environment measures, the maintenance and creation of other habitats, and the management of pesticide use, help protect and increase pollinator populations? This paper explores these questions by providing a farming perspective on the evidence in these areas; reflecting on what the knowns and unknowns are, and identifying where there are still gaps in the evidence that need to be plugged to better conserve and manage pollinators on farmland.

Globally, insect pollinators that are linked to increased yields in many crops have experienced severe population declines. Crop diversification is often proposed as an effective conservation measure to boost pollinator populations. Here, we investigate the potential benefits of mixed oilseed rape/milk vetch cultivation for wild pollinator communities by comparing it with oilseed rape monocultures. Studying 8 mixed and 10 monocropping fields positioned along a gradient of increasing semi‐natural habitat coverage in mountainous agricultural landscapes, we found that agricultural landscapes with mixed cultivation harboured higher wild pollinator diversity than oilseed rape monocropping landscapes. This positive effect was observed irrespective of the proportion of semi‐natural habitat. Meanwhile, the pollinator community composition in mixed cultivation landscapes was similar to that of oilseed rape monoculture landscapes, and, contrary to expectations, mixed cultivation did not benefit specific pollinator trait groups like cavity‐nesting bees. Overall, we believe the higher pollinator diversity linked to mixed cultivation can increase insect‐pollinated crop yields, and mixed oilseed rape‐milk vetch cultivation might represent a potential mitigation measure for the negative impacts agricultural intensification has on wild pollinator communities. [ABSTRACT FROM AUTHOR]

Despite growing awareness of the importance of monitoring wild crop pollinators worldwide, there are still few reports, especially in East Asia. Considering ongoing global warming may change the distribution range and diurnal activity of pollinators, it is necessary to describe current geographic and diurnal patterns. We clarified pollinators of Cucurbita maxima Duchesne (Cucurbitales: Cucurbitaceae) in three geographically distinct (>350 km, minimum) areas in Japan, focusing on diurnal variation. Apis mellifera L. (Hymenoptera: Apidae) and Halictidae (Hymenoptera) were observed in all of the experimental gardens. Apis cerana japonica Radoszkowski (Hymenoptera: Apidae) were mainly observed in Mie and Kagoshima, while Bombus diversus diversus Smith (Hymenoptera: Apidae) were observed only in Ibaraki. The peak time of flower visits depended both on bee taxa and area, and interestingly, did not necessarily synchronize with the timing of the highest pollen loads and the probability of stigma contact. In particular, visits and probability of contacting stigmas of Halictidae tended to increase as time passed, whereas pollen grains on their bodies sharply decreased with time; only a few individuals of Halictidae that visit early can become effective pollinators. There were no differences in yields between supplementary hand and natural pollination in all areas, and flower‐enclosure experiments using different mesh sizes clarified that small insects that can go across an approximately 4‐mm mesh may not transport sufficient pollen for fruit set. Our study demonstrated that pollination effectiveness, which is usually regarded as a static value, within a taxon can fluctuate in the space of just several hours. Considering such diurnal patterns can be altered by climate change, we need to carefully monitor the diurnal temporal patterns of pollinators worldwide. [ABSTRACT FROM AUTHOR]

Pollinator diversity and abundance are declining globally. Cropland agriculture and the corresponding use of agricultural pesticides may contribute to these declines, while increased pollinator habitat (flowering plants) can help mitigate them. Here we tested whether the relative effect of wildflower plantings on pollinator diversity and counts were modified by proportion of nearby agricultural land cover and pesticide exposure in 24 conserved grasslands in Iowa, USA. Compared with general grassland conservation practices, wildflower plantings led to only a 5% increase in pollinator diversity and no change in counts regardless of the proportion of cropland agriculture within a 1 km radius. Pollinator diversity increased earlier in the growing season and with per cent flower cover. Unexpectedly, neither insecticide nor total pesticide concentrations on above-ground passive samplers were related to pollinator diversity. However, pollinator community composition was most strongly related to date of sampling, total pesticide concentration, and forb or flower cover. Our results indicate very little difference in pollinator diversity between grassland conservation practices with and without wildflower plantings. Given the relatively high economic costs of wildflower plantings, our research provides initial evidence that investment in general grassland conservation may efficiently conserve pollinator diversity in temperate regions of intensive cropland agriculture.

Urbanization is increasing worldwide, with major impacts on biodiversity, species interactions and ecosystem functioning. Pollination is an ecosystem function vital for terrestrial ecosystems and food security; however, the processes underlying the patterns of pollinator diversity and the ecosystem services they provide in cities have seldom been quantified. Here, we perform a comprehensive meta‐analysis of 133 studies examining the effects of urbanization on pollinators and pollination. Our results confirm the widespread negative impacts of urbanization on pollinator richness and abundance, with Lepidoptera being the most affected group. Furthermore, pollinator responses were found to be trait‐specific, with below‐ground nesting and solitary Hymenoptera, and spring flyers more severely affected by urbanization. Meanwhile, cities promote non‐native pollinators, which may exacerbate conservation risks to native species. Surprisingly, despite the negative effects of urbanization on pollinator diversity, pollination service measured as seed set is enhanced in non‐tropical cities likely due to abundant generalists and managed pollinators therein. We emphasize that the richness of local flowering plants could mitigate the negative impacts of urbanization on pollinator diversity. Overall, the results demonstrate the varying magnitudes of multiple moderators on urban pollinators and pollination services and could help guide conservation actions for biodiversity and ecosystem function for a sustainable future. [ABSTRACT FROM AUTHOR]

Purpose: Insects constitute an important pollinator resource, and they are a key driver for both the fruit yield and the quality. It contributes in ensuring complete pollination and reproductive success of strawberries. However, the comprehensive benefits of insect pollinators in strawberry yield and fruit qualities through pollination are not quantified through empirical evidences. Therefore, this study quantifies the influence of pollinators on strawberry production. Research Method: The experiment was set up with two treatments (i.e., T1 - Open plots of strawberry, T2 - Mesh screen caged plot) arranged in a randomized complete block design with four replications per treatment. Opportunistic visual encounter and observational plot methods were followed to collect the insect pollinators sample. Further, the complete enumeration sampling was applied to collect strawberry plants sample. Findings: The results showed that during strawberry blossom, Tetramorium sp. was the prominent visitor (n = 506) followed by Apis cerana (n = 322). Based on the insects' foraging behavior, insect abundance and visit frequency, Apis cerana, Apis laboriosa, Xylocopa acutipennis, Bombus sp. and Junonia almana were recorded to be an effective Camarosa pollinator. The exclusion of pollinators in Camarosa resulted in smaller-sized and deformed fruits with inferior fruit quality attributes (color, shape and total soluble solids) compared to open plot fruits. The fruit quality attributes were significantly affected by pollination. Originality/Value: This study is the first of its kind to record the insect pollinators visiting Camarosa cultivar and study reported Tetramorium sp. as a successful pollinator in strawberries for the first time. [ABSTRACT FROM AUTHOR]

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the May 2020 newsletter includes updates on Visitor Plaza and Discovery Trail construction, spring wildlife sightings, and online species lists. The feature story focuses on bee research being done at NCOS. Community photos include Western Pygmy Blue Butterfly (Brephidium exilis), White-Faced Ibis (Plegadis chihi), and Caspian Tern (Hydroprogne caspia).

For most food crops the identity and efficiency of pollinators across key growing regions remains a significant knowledge gap that needs to be addressed before we can develop crop-specific approaches for pollination service delivery. Here, we conducted a systematic literature review and meta-analysis on watermelon (Citrullus lanatus (Thunb. Matsum. & Nakai)), a globally important fruit crop, to identify the floral visitors and their efficiency across different growing regions. We found that 265 insect species visit watermelon flowers (including 5 orders, 18 families and 75 genera) across 17 countries and 6 continents. Bees and flies were the most abundant flower visitors overall, but show distinct regional differences. Honey bees were the majority visitor in 53% of growing regions (range: 0 – 94%), whilst wild bee species were more abundant in 42% of regions (range: 3.4 – 100%). Honey bees and other bees were equally effective at depositing pollen on stigmas, but varied in effectiveness for fruit set and seed set. Pollination data from global studies appear to be limited for the largest-scale watermelon producers, namely: China, Turkey, and India, with the majority (56%) of data available from North America. This synthesis identified four key themes for improving pollination in watermelon: increasing honey bee densities on crops where local polices and environmental conditions are suitable; introducing other managed pollinators; identifying key wild pollinator taxa to encourage within crops; and improving local and landscape management practices to support pollinators.

Orchidaceae show remarkable diversity in pollination strategies, but how these strategies vary globally is not entirely clear. To identify regions and taxa that are data-rich and lend themselves to rigorous analyses or are data-poor and need attention, we introduce a global database of orchid reproductive biology. Our database contains > 2900 species representing all orchid subfamilies and 23 of 24 tribes. We tabulated information on habit, breeding systems, means of pollinator attraction and the identity of pollinators. Patterns of reproductive biology by habit, geography and taxonomy are presented graphically and analysed statistically. On the basis of our database, most orchid species sampled are pollinator dependent (76%) and self-compatible (88%). Pollinator attraction based on rewards occurs in 54% of the species, whereas 46% use some means of deceit. Orchids generally have highly specific pollinator interactions (median number of pollinator species = 1). Nonetheless, on average, specificity is lower for species offering rewards, occurring in multiple continental regions or Northern America (as defined by the Taxonomic Database Working Group Level 1 regions). Although our database reveals impressive knowledge gains, extensive gaps in basic observations of orchid reproductive biology exist, particularly in tropical regions and diverse lineages of fly-pollinated species. The database is expected to facilitate targeted studies, further elucidating the ecological and evolutionary drivers of orchid diversity. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is a highly cross pollinated crop that needs insect pollination (entomophily) for optimum seed set. In the present study, more than 120 insect species were noted to visit onion flowers, out of which fifty-nine species were collected through in-situ sampling technique and identified up to species level. The Indian bee (Apis cerana indica) was the most abundant insect pollinator visiting onion flowers in the study location. The pollination behaviour and foraging activity of A. c. indica were assessed, and the pollen foragers were observed to be swift flyers visiting a significantly higher number of flowers per minute during the peak flowering period and spending less time per flower (3 seconds) to collect nectar from deep seated nectaries of the flowers. The seed yield enhancement assessed through entomophily and artificial pollination methods showed that the open pollinated flowers recorded the highest yield statistically, followed by A. c. indica and A. mellifera pollinated flowers. However in artificial pollination treatments, sponge puff pollinated flowers recorded significantly high seed yield per hectare and percentage seed set per umbel, followed by camel brush, hand gloves (cloth) and hand gloves (rubber). In conclusion, all the cross pollination treatments were statistically significant on the closed pollination treatment concerning to the entire yield parameters calculated.

• Watermelon flowers attract diverse insect taxa but either honey bees or native bees are dominant in every region. • Honey bees and other bees are equally effective at pollen deposition on stigma. • Limited information located across major growing regions; majority of data is from North America. • Increasing bee density, encouraging wild taxa, and deploying land use practices will likely improve pollination. For most food crops the identity and efficiency of pollinators across key growing regions remains a significant knowledge gap that needs to be addressed before we can develop crop-specific approaches for pollination service delivery. Here, we conducted a systematic literature review and meta-analysis on watermelon (Citrullus lanatus (Thunb. Matsum. & Nakai)), a globally important fruit crop, to identify the floral visitors and their efficiency across different growing regions. We found that 265 insect species visit watermelon flowers (including 5 orders, 18 families and 75 genera) across 17 countries and 6 continents. Bees and flies were the most abundant flower visitors overall, but show distinct regional differences. Honey bees were the majority visitor in 53% of growing regions (range: 0 – 94%), whilst wild bee species were more abundant in 42% of regions (range: 3.4 – 100%). Honey bees and other bees were equally effective at depositing pollen on stigmas, but varied in effectiveness for fruit set and seed set. Pollination data from global studies appear to be limited for the largest-scale watermelon producers, namely: China, Turkey, and India, with the majority (56%) of data available from North America. This synthesis identified four key themes for improving pollination in watermelon: increasing honey bee densities on crops where local polices and environmental conditions are suitable; introducing other managed pollinators; identifying key wild pollinator taxa to encourage within crops; and improving local and landscape management practices to support pollinators. [ABSTRACT FROM AUTHOR]

Botanical gardens have contributed to plant conservation through the maintenance of both living and preserved plant specimens for decades. However, there is still a large gap in the literature about the potential conservation value that botanical gardens could provide to local pollinators. We investigated how plant-pollinator interaction network structure and diversity may differ between botanical gardens and native habitats by sampling and comparing two environments: a restored native grassland patch within a local botanical garden and fifteen native, remnant temperate grassland sites in the Northern Great Plains. We found pollinator diversity within the restored botanical garden’s native grassland patch to be at the high end of the distribution of the remnant temperate grassland sites throughout the entire flowering season. However, plant diversity and network community metrics between the two environments remained similar throughout, except that remnant temperate grasslands have more links (higher connectance) with pollinators than the garden patch. Overall, our findings demonstrate the promising role restored native grassland patches in botanical gardens could play as reservoirs for local pollinator communities by supporting plant-pollinator interactions comparable to those found in native habitat remnants in the same region.

This study highlights the potential of urban dry grasslands for diverse pollinator communities of wild bees and hoverflies, including rare and endangered species.By using pan trap sampling on 49 study sites distributed across the urban environment, responses of wild bee and hoverfly communities to urban features at two spatial scales (urban matrix and local habitat) were examined.A total of 1246 hoverfly individuals (Syrphidae) from 31 species and 1463 bee individuals (Apoidea) from 107 species were collected. Our analysis showed that hoverflies are impacted by urban matrix features and local floral resources, whereas wild bees only respond to patch size at the local habitat scale and endangered wild bee species additionally to non‐native pollinator‐friendly plants.Given the different responses of wild bees and hoverflies to the urban environment, we recommend multi‐taxon approaches for urban conservation practice. Urban dry grasslands and the diversity of pollinator‐friendly plants, including non‐native species, should be conserved and promoted to support urban pollinator diversity. [ABSTRACT FROM AUTHOR]

Pollinating insects provide pollination services to many crop species, including sweet cherry (Prunus avium L.), and this can be delivered by both managed and wild pollinators. Managed pollinators are often used to pollinate a range of fruit crops, but increasingly the role of wild insects is being studied. However, the importance of pollinator species depends on their relative abundance and pollination effectiveness, which depends on their foraging activity and their variability throughout the day. In this study, insect visitors of blossoms were observed in commercial sweet cherry orchards to explore abundance, diversity and pollination foraging behaviour of different insect pollinator groups throughout the day. A total of 1,174 pollinators from 31 different species were recorded visiting cherry blossoms over 2 years, of which 71.0% of total visits were by managed pollinators (western honeybee, Apis mellifera L. and buff‐tailed bumblebee, Bombus terrestris L.) compared to 29.0% by wild pollinators. On average, solitary bees visited a sweet cherry blossom for the longest duration (20.7 (±2.0 SE) seconds), whereas wild queen bumblebees visited the greatest number of flowers per minute (mean of 19.0 (±1.3 SE)). As both these pollinator groups contacted cherry stigmas more often and moved more frequently between tree rows than managed bees and hoverflies, they are more likely to facilitate cross‐pollination. The different pollinator groups also showed variation in behavioural parameters throughout the day, but less variation was recorded when all pollinator groups were considered altogether. This suggests diverse pollinator communities might be expected to provide a more stable pollination service to sweet cherry. This study demonstrates that whilst cherry blossoms were more frequently visited by managed pollinators, wild solitary bee and bumblebee behaviours are likely to be more effective at enhancing pollination in sweet cherry orchards, which, in turn, might lead to increased yields. [ABSTRACT FROM AUTHOR]

Premise: Yeasts are often present in floral nectar and can influence plant fitness directly (independently of pollinators) or indirectly by influencing pollinator visitation and behavior. However, few studies have assessed the effect of nectar yeasts on plant reproductive success or compared effects across different plant species, limiting our understanding of the relative impact of direct vs. indirect effects. Methods: We inoculated the nectar of six plant species in the field with the cosmopolitan yeast Metschnikowia reukaufii to analyze the direct and indirect effects on female reproductive success over 2 years. The pollinator assemblage for each species was recorded during both flowering years. Results: Direct yeast effects on female fecundity were statistically nonsignificant for all plant species. There were significant indirect, pollinator‐mediated effects on fruit production and seed mass for the two species pollinated almost exclusively by bumblebees or hawkmoths, with the direction of the effects differing for the quantity‐ and quality‐related fitness components. There were no consistent effects of the yeast on maternal fecundity for any of the species with diverse pollinator assemblages. Conclusions: Effects of M. reukaufii on plant reproduction ranged from negative to neutral or positive depending on the plant species. The among‐species variation in the indirect effects of nectar yeasts on plant pollination could reflect variation in the pollinator community, the specific microbes colonizing the nectar, and the order of microbial infection (priority effects), determining potential species interactions. Elucidating the nature of these multitrophic plant–pollinator–microbe interactions is important to understand complex processes underlying plant pollination. [ABSTRACT FROM AUTHOR]

Studying pollinator diversity and their abundance is essential to analyze the health of the agroecosystem. This study undertook observations on the number of pollinators visiting the flowers/m2 for 5 min at randomly selected ten spots in the agroecosystems in West Bengal. The diversity index was measured by Simpson's Index of Diversity. A total number of 55 individuals of insect pollinators belonging to 19 families and four orders were observed of which Hymenoptera were maximum (47.25%) followed by: Coleoptera (24.68%), Lepidoptera (11.26%) and Diptera (8.29%). Simpson's index ranged from 0 to 1. and maximum species richness was found in Lower Bongbasti, Kalimpong (0.995) and the least at ABBlock farm BCKV Kalyani (0.751). Among the surveyed areas, species evenness was found maximum in Khelia North 24 Parganas (1.34) and the least in Jhanti Pahari Bankura (0.14). So far as pollinator species richness is concerned, it was maximum in hilly terrains of Kalimpong followed by North 24 Parganas, Bankura and Nadia. [ABSTRACT FROM AUTHOR]

Abstract Aim Bumble bees (Hymenoptera: Apidae: Bombus) are economically and ecologically important pollinators in agroecosystems and wildland habitats. In the Nearctic region, there are approximately 41 species, of which the IUCN lists twelve species as vulnerable, endangered, or critically endangered. We conducted a standardized faunal survey to inform ongoing conservation efforts including petitions under review for the Endangered Species Act. Furthermore, we test the appropriateness of a methodology for accurately sampling bumble bee communities. Location The United States of America, including 31 sites in 15 states. Methods We surveyed 15 states in the summer of 2015 to assess community composition and relative species abundance at agricultural and seminatural sites throughout the United States. We collected approximately 100 bees, using aerial nets, from each of 31 sites and identified specimens to species, totaling 3,252 bees. We assessed our survey methodology to understand whether it accurately sampled the potential community of bumble bees at each site for utility in future monitoring efforts. Results Average site species richness was 5.1 ± 2.05, and we detected 30 of the 41 species documented historically within the contiguous United States. Sampling a site beyond 100 bees rarely added additional species detections, whereas adding additional sampling sites within an ecoregion frequently increased the species richness for the ecoregion. Thirteen of the 30 species we detected each accounted for

Abstract To increase the resilience of our food system, we must better understand how ecosystem services such as pest control and pollination provided by a diverse insect community contribute to crop yield. We examined how landscape heterogeneity relates to insect and pollinator diversity, and how insect and pollinator diversity relates to yield of Brassica carinata, a new biofuel crop within common farming practices. Over two years, we planted 35 × 1 acre sites in a roughly 1000‐km2 area near Brookings, South Dakota, in the Prairie Coteau. We randomly assigned each site to a combination of three common farming practices: tilling (yes/no), added honey bee hives (yes/no), and treatment with systemic neonicotinoids (yes/no). Insect and pollinator diversity and the heterogeneity of the surrounding landscape at multiple spatial scales were calculated. We observed a significant positive relationship between insect (and pollinator) diversity and yield when fields were untreated, without hives, nor seed treatments. All farming practices within this study increase yield. However, farming practices alter the relationship between yield and insect (and pollinator) diversity. The addition of seed treatment or tillage negates the relationship between insect (and pollinator) diversity with yield. There was no relationship between seed treatment, diversity, and yield for all insects, and the application of seed treatment resulted in lower pollinator diversity. Increased landscape heterogeneity was correlated with more insect diversity at the 1000‐m scale and pollinator diversity at the 3000‐m scale. Our results show that increasing large‐scale landscape heterogeneity increases insect diversity, which serves as a substitute for common farming practices such as application of pesticides, tilling, or bee hives. Increased landscape heterogeneity could increase farmers' net profitability by replacing input costs associated with tillage and seed treatments.

To increase the resilience of our food system, we must better understand how ecosystem services such as pest control and pollination provided by a diverse insect community contribute to crop yield. We examined how landscape heterogeneity relates to insect and pollinator diversity, and how insect and pollinator diversity relates to yield of Brassica carinata, a new biofuel crop within common farming practices. Over two years, we planted 35 × 1 acre sites in a roughly 1000‐km2 area near Brookings, South Dakota, in the Prairie Coteau. We randomly assigned each site to a combination of three common farming practices: tilling (yes/no), added honey bee hives (yes/no), and treatment with systemic neonicotinoids (yes/no). Insect and pollinator diversity and the heterogeneity of the surrounding landscape at multiple spatial scales were calculated. We observed a significant positive relationship between insect (and pollinator) diversity and yield when fields were untreated, without hives, nor seed treatments. All farming practices within this study increase yield. However, farming practices alter the relationship between yield and insect (and pollinator) diversity. The addition of seed treatment or tillage negates the relationship between insect (and pollinator) diversity with yield. There was no relationship between seed treatment, diversity, and yield for all insects, and the application of seed treatment resulted in lower pollinator diversity. Increased landscape heterogeneity was correlated with more insect diversity at the 1000‐m scale and pollinator diversity at the 3000‐m scale. Our results show that increasing large‐scale landscape heterogeneity increases insect diversity, which serves as a substitute for common farming practices such as application of pesticides, tilling, or bee hives. Increased landscape heterogeneity could increase farmers' net profitability by replacing input costs associated with tillage and seed treatments. [ABSTRACT FROM AUTHOR]

Pollinators are rewarding for many wild and agricultural crop plants. The experiments were conducted in the agricultural field of Karad tehsil, Maharashtra, India. The present study concentrated on the diversity and species richness of nocturnal insect pollinators on Ridge gourd Luffa acutangula belonging to the family Cucurbitaceae. The Ridge gourd plant is monoecious with a bunch of male flowers and solitary female flower. Anthesis happened in late evening hours (17.00-19.00) and flowers remained for 13 to 14 hours. A total of 830 insect pollinators were sampled from June 2020 to November 2020. Altogether 17 species of insect pollinators belonging to 7 families under 6 orders were recorded. Among the total number of species, the Lepidoptera was the dominant order comprising 11 species belonging to the single family Crambidae followed by Blattodea comprising 2 species belonging to 2 families Ectobiidae and Blattidae. Hymenoptera comprised 1 species belonging to family Formicidae, followed by order Orthoptera comprising 1 species belonging to family Gryllidae, order Diptera comprising 1 species belonging to the family Culicidae, followed by the order Coleoptera comprising 1 species belonging to the family Chrysomelidae. The Diaphnia hyalinata belonging to family Crambidae of the order Lepidoptera was the most dominant species and was followed by Chabula acamasalis. The nocturnal species imparted pollination services to agricultural crops. The study also observed fundamental mechanisms of plant and nocturnal insect pollinator interaction as well as floral scent and visual signals. The study can be baseline data for conserving and managing the best pollinators for increasing the yield of Ridge gourd. [ABSTRACT FROM AUTHOR]

Declines in pollinating invertebrates across intensively cultivated landscapes linked to reductions in flower‐rich habitats constitute a key threat to biodiversity conservation and the provision of ecosystem services. Over recent decades, many ponds in agricultural landscapes have become overgrown with woody vegetation, resulting in heavily shaded, flower‐poor pond basins and margins. Restoration of farmland ponds through removal of sediment and encroaching woody vegetation (canopy management) from pond margins greatly enhances freshwater biodiversity. Nevertheless, the consequences of pond management for pond‐margin plants and pollinating insects remain poorly understood. Here, we studied these effects for ponds in Norfolk, eastern England.We compared richness, abundance and composition of pollinating insects (hymenopterans and syrphids) and insect‐pollinated plant communities between open‐canopy pond systems subjected to either (i) long‐term regular management of woody vegetation or (ii) recent restoration by woody vegetation and sediment removal with those communities at (iii) ponds dominated by woody vegetation.Canopy management increased the richness and abundance of pollinators and insect‐pollinated plants. Pollinator richness and abundance was best explained by improvements in flower resources at open‐canopy ponds. Management most strongly influenced hymenopteran communities.Ponds represent important semi‐natural habitats for insect‐pollinated plant and pollinator communities in farmland. To enhance food resources, diversity and abundance of diurnal pollinators, conservation management at ponds should aim for mosaics of ponds at different successional stages with a high proportion of early successional open‐canopy ponds. Agricultural ponds are emerging as important habitats not only for aquatic biodiversity, but also for terrestrial species, thus warranting their prioritisation in future agri‐environment schemes. [ABSTRACT FROM AUTHOR]

The diversity and abundance of native bees (Hymenoptera: Anthophila) are important in providing pollination services to a diverse array of crops. An extensive literature base is available on the contributions of bees as crop pollinators. The focus of the majority of these studies are on honey bees (Apis spp.) pollinating crops that depend on cross-pollination to produce a yield. Self-pollinating crop species, including cotton, soybeans, coffee, and canola, can self-pollinate but there is increasing evidence that they can also benefit from cross-pollination by insects. These crops can see a considerable benefit when visited by bees in general, but contradictory evidence is not fully understood in some systems. For example, recent studies have shown that bee visitation to cotton blooms can increase yield up to 15%. Including nesting habitat for non-Apis bees within soybean dominated landscapes increases in-field yields. However, in these same systems, some studies show none or minimal yield increases. Additional literature (both recent and historical) of non-Apis bees in mass-flowering self-pollinating crops and their potential benefits to the crops also exists but is previously unsynthesized in cotton and soybeans in particular. In our review of literature on these select self-pollinating crops, there appears to be apparent gaps in the literature base on these and other understudied cropping systems. With the exception of graminaceous and cereal crops, all the crops discussed herein seem to have all have benefited from visitation by both Apis and non-Apis bees. Some provide known resource benefits to native bee pollinators like canola, but others like cotton and soybean are not well understood. Further, with an apparent yet small literature base in cotton and soybean there are many facets between the native bee pollinators and crop such as nutritional benefits of nectar and pollen to the bees themselves that still need to be addressed. To examine these underlying mechanisms, additional studies into the basic biology and natural history, including nesting habitats and preferences along with foraging preferences of abundant bee species will help understand how these bees seem to persist and possibly thrive in intensified agricultural systems. [ABSTRACT FROM AUTHOR]

Pollinator declines have been documented globally, but little information is available about native bee ecology in Midwestern U.S. agriculture. This project seeks to optimize pollinator support and weed suppression in a 3-yr crop rotation with a fallow growing season. During fallow, one of five cover crop treatments (T1: crimson, red, and ladino clover and Bob oats [Fabales: Fabaceae - Trifolium incarnatum L. Trifolium pratense L. Trifolium repens L. and Cyperales: Poaceae - Avena sativa ]; T2: crimson clover and oats; T3: red clover and oats; T4: ladino clover and oats; T5: no cover crop; T6/control: winter wheat [Cyperales: Poaceae - Triticum aestivum ] L.) was seeded in one-half of 25 agricultural fields, whereas wheat was left unharvested in the other half as a comparison. Treatments that provide season-long floral resources support the greatest bee diversity and abundance (T1), and treatments with red clover support declining (Hymenoptera: Apidae) Bombus species (T1 and T3). Late-season floral resources may be important, yet limited (T1 and T4), and some species of agricultural weeds provide floral resources. Floral diversity may be less important than flower abundance or timing for pollinator diversity (T1–T4). Weed diversity was greatest in the no cover crop treatment (T5), least in winter wheat (T6), and intermediate in cover crop treatments (T1–T4) with no differences in weeds of economic concern. Wheat suppresses weeds but does not provide floral resources for pollinators. These results may also be applicable to marginal lands taken out of cultivation or field margin pollinator plantings in a typical corn–soybean rotation. Floral resource availability across the landscape is critical to maintain pollinator diversity. [ABSTRACT FROM AUTHOR]

Pollination is one of the important ecosystem services related to sustainable development of human society. However, the population diversity and abundance of wild bees, important pollinators, have been significantly reduced by climate change, agricultural intensification, and landscape transformation. Re-establishment of pollinator habitat by planting nectar-producing plants is an important way to maintain pollination service. In this study, we investigated the status of wild bees and the traits of flowering plants in 22 apple orchards during flowering stage in Changping District, Beijing in 2019. We analyzed the response of wild bee diversity to the flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in apple orchards, aiming to provide guidance for the selection of nectar-producing plants to establish the habitat of wild bees. A total of 3517 wild bees were captured during the apple flowering season, representing 49 species, 13 genera, and 5 families. We identified 21 flowering plants species that shared a similar flo-wering period with apple, exhibiting a range of 5 colors and 9 inflorescence types. The Shannon diversity index, evenness index, and social bee richness of wild bee community were positively correlated with flowering plant richness. The total wild bee community richness, social bee richness, underground nesting bee richness were positively correlated with the richness of flowering plant color, but Halictidae bee abundance was negatively correlated with the richness of flowering plant color. The Shannon diversity index and evenness index of wild bee community were positively correlated with the richness of inflorescence types. Megachilidae bee richness was negative correlated with the white flower coverage. Megachilidae bee richness, social bee abundance, and ground nesting bee richness were positively correlated with the purple flower coverage. There was no significant correlation between wild bees and flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in other communities of different families, lifestyles and nesting types. Maintaining diverse ground flowering plants with various traits in orchards is important to improve the diversity of wild bees. In particular, increasing the coverage of purple flower during apple flowering period is helpful to promote the diversity of Megachilidae bee, social bees, and ground nesting bees.

The persistence of Conservation Reserve Program (CRP) seed mixtures following planting is crucial for the long-term support of pollinator habitat; however, the role of disturbance regimes and their interactions in supporting this ecosystem service are largely unknown. This study set out to evaluate how ecological disturbances (prescribed burn, light disking, or fallow control) and commercially available diverse species mixtures (‘Hamilton’, ‘Bamert’, and ‘Holland’) affect pollinator habitat and the flowering period of commonly used CRP species mixtures. Specifically, three pollinator species mixtures were assessed for plant stand dynamics (plant density, yield, and dual-use pollinator-lignocellulosic feedstock potential); the resulting soil properties; and the total bloom count during the growing season. Following 5 years after their establishment, the proportions of flowering pollinator species varied by disturbance regime × seed mixture (p < 0.05), with the burned Hamilton and disked Holland plots having the greatest pollinator species percentages. Overall, if the long-term stability of pollinator blooms is a key consideration for management, the Hamilton mixture should be disturbed via prescribed burning, while the Holland mixture should be disked, owing to a species-specific disturbance regime preference. However, post-senescence yield and soil health properties did not vary (p > 0.05) across pollinator mixtures or disturbance regimes. Pollinator mixtures could also be harvested as a lignocellulosic feedstock without damaging pollinator habitat and providing comparable biomass for regional feedstocks; however, seeding mixtures and disturbance regimes should be considered based on desired residue usage for long-term sustainable CRP pollinator habitat.

Preserving species diversity is critical to ensure ecosystem functioning; however, different components of diversity might respond to human disturbance in different ways. Similarly, trophic levels might have uncoupled responses to the same disturbance, thus ameliorating or aggravating the persistence of ecological communities. In this study, we analysed how the density, richness and evenness of flowers and pollinators respond to four levels of woodland thinning intensity (0, 30, 50 and 70% of woodland basal area removed) over 2 years in three contrasting sites. We found a mismatch in the response of flowers and pollinators to thinning. Flower density and richness had disparate responses, depending on the site and year, while evenness did not change with thinning. In contrast, pollinator density and richness, but not evenness, consistently increased with thinning among years and sites. These results suggest that thinning has a great influence on pollinators through changes in abiotic conditions and, perhaps, flower attractiveness rather than through small‐scale changes in flower density and richness. At the site where tree flowers were absent, bee pollinator community composition was impoverished, suggesting that trees provide important floral resources to pollinators. Our findings indicate that disturbance may diminish local plant abundance and richness, but pollinator abundance and richness are enhanced after intense thinning at small scales. [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.) seed crops require insects for pollination. Apis mellifera Linnaeus, 1758 are normally placed within fields but other insects might also be contributing additional pollination. To understand their potential contribution, we evaluated abundances across fields during peak flower; measured loose body pollen on four bee and two fly species and compared the rate of movement between inflorescences and florets for A. mellifera and B. terrestris (Linnaeus, 1758). A. mellifera were the most abundant verified flower visitor, although B. terrestris and long-tongued Bombus species also visited fields. Other insects recorded included Lasioglossum bees and two hover fly species, but these were considered ineffective pollinators (either low abundances or carried few pollen grains). B. terrestris were considered a more efficient pollinator than A. mellifera moving faster between florets but were less effective due to low abundances. Many Bombus spp. will forage under weather conditions unfavourable to A. mellifera, therefore, providing complimentary pollination. [ABSTRACT FROM AUTHOR]

Aim: Bumble bees (Hymenoptera: Apidae: Bombus) are economically and ecologically important pollinators in agroecosystems and wildland habitats. In the Nearctic region, there are approximately 41 species, of which the IUCN lists twelve species as vulnerable, endangered, or critically endangered. We conducted a standardized faunal survey to inform ongoing conservation efforts including petitions under review for the Endangered Species Act. Furthermore, we test the appropriateness of a methodology for accurately sampling bumble bee communities. Location: The United States of America, including 31 sites in 15 states. Methods: We surveyed 15 states in the summer of 2015 to assess community composition and relative species abundance at agricultural and seminatural sites throughout the United States. We collected approximately 100 bees, using aerial nets, from each of 31 sites and identified specimens to species, totaling 3,252 bees. We assessed our survey methodology to understand whether it accurately sampled the potential community of bumble bees at each site for utility in future monitoring efforts. Results: Average site species richness was 5.1 ± 2.05, and we detected 30 of the 41 species documented historically within the contiguous United States. Sampling a site beyond 100 bees rarely added additional species detections, whereas adding additional sampling sites within an ecoregion frequently increased the species richness for the ecoregion. Thirteen of the 30 species we detected each accounted for <1% of the total fauna, and two species accounted for 49.02% of all bees captured. Species richness and evenness increased with increasing latitude across communities. Main Conclusions: Species diversity and evenness in bumble bees increases in northern latitudes and increasing elevation in the United States; however, a few common species tend to dominate communities while many species occur only in low numbers. The results of this survey effort can inform current conservation evaluations and planning. Bumble bee communities vary across the United State and several species are considered to be at risk. We assessed the community structure and evaluated a sampling technique at 31 sites in 15 states in 2015. We suggest that sampling methods were adequate to assess community structure and provide much needed baseline data for further monitoring efforts. [ABSTRACT FROM AUTHOR]

The drone fly (Eristalis tenax) pollinates many crops and is found almost worldwide. Its successful management as a field-crop pollinator would provide an additional option to augment bee pollination. We reviewed literature to assess their management potential. A literature search was conducted for information on drone-fly abundance across New Zealand crops, pollinator effectiveness, lifecycle-requirements and potential for mass rearing. Relevant literature was then evaluated to assess the feasibility, benefits and limitations of their management. Eristalis tenax is a proven pollinator of pak choi (Brassica rapa spp. chinensis), kiwifruit (Actinidia deliciosa) and onion (Allium cepa), and visits the flowers of several more crops in New Zealand. It readily completes its lifecycle under laboratory conditions when reared on various organic materials. No reviewed studies were identified that showed successful management of populations for the purpose of field-crop pollination. Key challenges for their management as field-crop pollinators include: being able to mass rear them at an appropriate scale; retaining numbers within targeted areas in the field; and ensuring their use does not significantly impact on non-target species and land-user interests. [ABSTRACT FROM AUTHOR]

There is growing demand for pollination services in agricultural production, which contrasts with declines of wild and managed pollinator populations. Macadamia ( Macadamia integrifolia) is a mass-flowering crop that depends on pollination services and is increasingly cultivated in South Africa. We studied the crop’s pollination in South African orchards considering variation in landscape context and the spatial arrangement of managed honeybees ( Apis mellifera ). We conducted pollination experiments and pollinator observations on macadamia trees along a distance gradient from orchard edges that bordered either near-natural or human-modified habitats. In addition, we mapped position and density of honeybee apiaries at orchard-level. Nut set of macadamia trees strongly relied on animal-mediated pollination: pollinator exclusion reduced the initial nut set (3 weeks after pollination) by 80% and the final nut set (15 weeks after pollination) by 54%. Supplemental hand-pollination of otherwise untreated flowers increased initial and final nut set by 66% and 44%, respectively, indicating substantial pollination limitation. The landscape context only weakly affected pollinator visitation to macadamia trees, with reduced visitation closer to orchard edges bordering human-modified habitats. Furthermore, we observed almost no wild pollinator species. Instead, honeybees constituted 99% of all visits, whereby honeybee visitation rates increased with a tree’s connectivity to apiaries. However, neither initial nor final nut was related to visitation rates, and the final nut set was actually reduced where honeybee colony density was high, with a predicted 50% reduction in final nut set between the lowest and highest colony densities. Our study demonstrates a strong pollination limitation in South African macadamia orchards, where managed honeybees fail at delivering the increasing need for pollination services. Indeed, increasing their colony densities may further limit their pollination efficiency. A pollination management that also includes non- Apis managed pollinators and wild pollinators is possibly needed to increase nut set and provide solutions for increasing pollination service demands. In intensive macadamia orchards, this can also necessitate the need for more pollinator-friendly management practices, including habitat restoration and reduced pesticide application. [ABSTRACT FROM AUTHOR]

Over time, agricultural systems have undergone intensification with a view to increasing food production and security. However, the resulting land use conversions have led to declines in biodiversity and ecosystem services, such as pollination, and have thus negatively affected food production and security. It may be that the harmful impacts of conventional agriculture could be somewhat mitigated by diversifying current farming systems. Notably, the incorporation of agroforestry can provide suitable habitat for native pollinators and thus maintain pollination services. In recent years, several studies have examined pollination dynamics in agroforestry systems. However, their findings remain scattered, and the effects of agroforestry practices on pollination have generally been approached from a theoretical rather than an experimental point of view. Here, we reviewed the literature published to date on pollination in agroforestry systems across the world with a view to identifying general trends, gaps in knowledge, and future opportunities. To this end, we systematically characterized and quantified the research based on its biogeographical, economic, and ecological facets, and we synthesized discoveries about how agroforestry practices influence pollinators and pollination services. Our results highlight that, compared to conventional agriculture, agroforestry generally promotes or maintains pollination services. Therefore, this review supports the perspective that agroforestry systems represent a sustainable alternative to conventional agricultural systems. Future research should focus on improving understanding of how crop management intensity, irrigation, and organic inputs affect pollination services. We need more studies looking at a broader range of crop species and pollinator guilds as well as research examining the effects of crop management intensity on plant-pollinator interaction networks. • Agroforestry mitigates the impacts of conventional agriculture on pollination. • Pollination could be better maintained by agroforestry than conventional agriculture. • Understanding of pollination dynamics in agroforests needs to be improved. • Public policies are needed to encourage implementation of agroforestry practices. [ABSTRACT FROM AUTHOR]

Brassica napus and Brassica rapa are grown across six continents for purposes including oilseed, biofuel, vegetables and livestock fodder. Hybridisation between the two can downgrade seed quality reducing grower returns. We assess the similarity of flower visitor assemblages of both species to determine the applicability of pollinator management strategies to both. Insect taxa were collected using window traps placed within ten peak- flowering fields, five each of B. napus and B. rapa (one cultivar/species) located in South Canterbury, New Zealand. Both crops contained similar flower visitor assemblages with 25 of 29 taxa in common. Of the 1549 insects counted, Apis mellifera was most abundant (~40% of individuals in both crops). Bombus terrrestris and the flies Delia platura, and Oxysarcodexia varia were also common. Crop location more likely influenced assemblage composition than crop species. Strategies to boost the role of bee and non-bee pollinators have potential benefits for both crops; however, a broader understanding of pollinator movement between crops is required to optimise seed purity and crop spacing. [ABSTRACT FROM AUTHOR]

Aim Agricultural intensification and urbanization are important drivers of biodiversity change in Europe. Different aspects of bee community diversity vary in their sensitivity to these pressures, as well as independently influencing ecosystem service provision (pollination). To obtain a more comprehensive understanding of human impacts on bee diversity across Europe, we assess multiple, complementary indices of diversity. Location One Thousand four hundred and forty six sites across Europe. Methods We collated data on bee occurrence and abundance from the published literature and supplemented them with the PREDICTS database. Using Rao's Quadratic Entropy, we assessed how species, functional and phylogenetic diversity of 1,446 bee communities respond to land-use characteristics including land-use class, cropland intensity, human population density and distance to roads. We combined these models with statistically downscaled estimates of land use in 2005 to estimate and map-at a scale of approximately 1 km2-the losses in diversity relative to semi-natural/natural baseline (the predicted diversity of an uninhabited grid square, consisting only of semi-natural/natural vegetation). Results We show that-relative to the predicted local diversity in uninhabited semi-natural/natural habitat-half of all EU27 countries have lost over 10% of their average local species diversity and two-thirds of countries have lost over 5% of their average local functional and phylogenetic diversity. All diversity measures were generally lower in pasture and higher-intensity cropland than in semi-natural/natural vegetation, but facets of diversity showed less consistent responses to human population density. These differences have led to marked spatial mismatches in losses: losses in phylogenetic diversity were in some areas almost 20 percentage points (pp.) more severe than losses in species diversity, but in other areas losses were almost 40 pp. less severe. Main conclusions These results highlight the importance of exploring multiple measures of diversity when prioritizing and evaluating conservation actions, as species-diverse assemblages may be phylogenetically and functionally impoverished, potentially threatening pollination service provision. [ABSTRACT FROM AUTHOR]

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