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An increasing number of recent studies show that nectar-inhabiting microorganisms influence plant fitness by mediating interactions between plants and pollinators. However, whether the effects of nectar microbes extend beyond pollination to affect subsequent stages of plant reproduction remains largely unknown. This study aims to explore whether nectar microbes can indirectly affect fruit consumption by birds, which can be essential for seed dispersal and germination. Wild flowers of Eurya japonica trees were experimentally inoculated with the nectar-inhabiting yeast Metschnikowia reukaufii and the nectar-inhabiting bacterium Acinetobacter boissieri , both of which had been previously isolated frequently from E. japonica flowers. In this experiment, I examined whether these microbes changed female reproductive success of the understory tree. Experimental inoculation of flowers with yeasts decreased fruit and seed set compared to those inoculated with bacteria, and the control. Furthermore, fruits with higher seed set tended to be larger, and larger fruits were more likely to be consumed by seed-dispersing birds, including the Japanese white-eye Zosterops japonica, the brown-eared bulbul Hypsipetes amaurotis , and the Daurian redstart Phoenicurus auroreus. These results suggest that nectar-inhabiting microorganisms have the potential to affect plant reproduction by influencing not only plant-pollinator interactions, but also by indirectly modifying plant-frugivore interactions via changes in plant-pollinator interactions. [ABSTRACT FROM AUTHOR]

Sowing of wildflower strips has been integrated in agri-environment schemes of several European countries. Their beneficial effects on natural enemies of pest insects are well documented but (1) the desired spill-over into crop fields has not always been demonstrated, and (2) the need to adapt sown mixtures to regional climatic differences has been rarely addressed. We set up a multi-site experiment in different French climatic regions to compare effects of a wildflower strip with a grass mixture and spontaneous vegetation. The design included five regions, three to five fields per region and the three strip treatments being repeated in each field. We tested strip treatment effects on vegetation (plant species richness, plant and flower cover) and on natural enemies (hoverflies, ladybirds, aphid predation). In a subset, we further analysed the spill-over into winter wheat fields including natural enemies and pest insects (cereal aphids, leaf beetles). The wildflower strip mixture developed well in all regions and increased plant species richness and flower cover compared with grass strips and spontaneous vegetation. We found a corresponding higher hoverfly abundance and aphid predation in wildflower strips that were consistent in all regions, whereas ladybird abundance was not affected. A significantly higher hoverfly abundance, aphid predation and aphid parasitism in wheat fields close to wildflower strips indicated a spill-over. No corresponding margin treatment effects were observed for aphid and leaf beetle abundance in the field. A multivariate analysis comparing the influence of climate and vegetation parameters showed that floral cover better explained variation in natural enemy abundance and predation than climate. Our results demonstrated that similar mixtures of native plants can be used over large climatic gradients to improve biocontrol. Further research is needed to improve spill-over into crop fields and to obtain consistently strong effects in different climate zones. [ABSTRACT FROM AUTHOR]

The yield of many agricultural crops depends on pollination services provided by wild and managed bees, many of which are experiencing declines due to factors such as reductions in floral resources. Thus, improving pollinator habitat on farmlands using management strategies like planting wildflower strips is vital for wild bee conservation and sustainable crop pollination. Yet, few studies have examined whether and at what spatial scales wildflower strips enhance crop pollination and yields, and most research has been conducted in large-scale commercial agriculture. Therefore, we investigated the effects of wildflower strips on crop pollination on small, diversified farms (i.e., those growing a variety of crop species) where wild bee diversity and abundance is predicted to be comparatively high. Over three years, on four diversified farms in Montana USA, we tested the hypothesis that distance (20, 60, and 180 m) of crops from native perennial wildflower strips planted alongside crop fields affected wild bee visitation, pollination, and yields of squash and sunflower crop plants. We found that distance to wildflower strips did not affect bee visitation or pollination in crops. Squash yield was pollen-limited in the growing season prior to wildflower strip establishment, and in one of the two years after wildflower strip establishment, but proximity to wildflower strips did not influence the magnitude of pollen limitation. Sunflower seed production was not pollen-limited in any year. Our findings demonstrate that even on diverse farms with wildflower strips and a demonstrated high diversity of bees, some crops do not necessarily receive maximum pollination, regardless of distance from the wildflower strips. However, the value of wildflower strips for supporting wild bee diversity, and other ecological or economic benefits, needs consideration for a full understanding of this pollinator habitat management strategy. [ABSTRACT FROM AUTHOR]

Contemporary approaches to agriculture must be reimaged to include ecological techniques that maximise ecosystem services, so that food can be produced sustainably whilst simultaneously meeting yield demands. Pest regulation services, harnessed through the conservation of natural enemies in the agri-environment are an economically important service degraded by conventional citrus production practices. For the first time, a sown wildflower strip composed of native forbs and tussock-forming grasses has been investigated for its influence on natural enemies and their pest regulation services in citrus orchards. A novel management strategy was applied, using the predicted generation times of Aonidiella aurantii Maskell (Hemiptera: Diaspididae) , a key pest in citrus, to determine whether cutting the wildflower strips could force spill-over of natural enemies onto the adjacent crop, enhancing pest regulation services. Three treatments applied to orange orchard alleyways were compared: i) a control treatment, the standard orchard practice of regular cutting to 5 cm throughout the year, ii) a sown wildflower treatment managed with cutting once a year in February to a height of 10 cm (standard management wildflower treatment, SMWT), and iii) the same sown wildflower treatment but managed with two additional cuts in May and June (active management wildflower treatment, AMWT). Orange tree canopies were sampled for natural enemies, and pest regulation services were quantified using sentinel prey cards baited with Ephestia kuehniella eggs. Natural enemy richness was greatest in canopies with SMWT, supporting a greater relative abundance of primary parasitoids and lower relative abundances of antagonists (ants) compared to the control. This was associated with enhanced pest regulation services (depletion of sentinel prey from baited cards), especially during the early summer months, which coincides with a critical period to control A. aurantii and other key citrus pests. In contrast, AMWT did not enhance natural enemy richness, and pest regulation services were diminished. This study suggests that leaving wildflower strips uncut throughout the season, as in SMWT, may help to mitigate pest incidence through enhanced pest regulation services. Further studies are now required to determine how this would influence populations of target pests. • A sown wildflower strip composed of native forbs and tussock-forming grasses is investigated for its influence on natural enemies and associated pest regulation services in citrus orchards. • Different management practices were compared, including a novel strategy to determine whether cutting the wildflower strips (active management) could force spill-over of natural enemies onto the adjacent crop. • Wildflower strips supported greater relative abundance of primary parasitoids and lower relative abundances of antagonists compared to the control. • There was no evidence of forced spill-over by cutting the wildflower strips. Natural enemy richness and pest regulation services were similar in the crop adjacent to active management wildflower strips as in the control. • Natural enemy richness was greatest in the citrus crop adjacent to wildflower strips that were left uncut throughout the season and this translated to enhanced pest regulation services. [ABSTRACT FROM AUTHOR]

Anagyrus vladimiri (Hymenoptera: Encyrtidae) is the main parasitoid of Planococcus citri (Hemiptera: Pseudococcidae), which is one of the most important pests of citrus crops in the Mediterranean Basin. Pesticide residue on trees and in the nectar of wildflowers growing in citrus orchards might cause side effects in beneficial insects. In the present study, we assessed the effects of six systemic pesticides (acetamiprid, dimethoate, cyantraniliprole, flupyradifurone, spirotetramat and sulfoxaflor) on the survival and progeny of A. vladimiri. Anagyrus vladimiri fed on the pesticide solutions and on the nectar of Fagopyrum esculentum Moench plants that had been watered with a solution containing these pesticides. Acetamiprid, dimethoate, flupyradifurone and sulfoxaflor increased female mortality more than the control (water) after 6h; after A. vladimiri consumed these pesticides, female mortality ranged from 62% to 73%. Cyantraniliprole had no immediate toxic effect on parasitoid survival but caused mortality after 15 days. All tested pesticides except flupyradifurone and spirotetramat reduced parasitoid progeny. After six days of feeding on F. esculentum nectar of plants watered with a pesticide solution, significantly increased female mortality was observed with dimethoate (96%), spirotetramat (80%), acetamiprid (62%), cyantraniliprole (62%) and sulfoxaflor (50%). Progeny was reduced in females that fed on plants treated with spirotetramat and dimethoate. These results demonstrate that some of these insecticides can have lethal or sublethal effects on A. vladimiri by both routes of exposure, via direct or indirect pesticide consumption through the nectar of treated plants. • Pesticides that systemically reach the nectar can negatively affect parasitoids. • Anagyrus vladimiri fitness was negatively affected by direct pesticide consumption. • Treated plants nectar consumption have lethal or sublethal effects on A. vladimiri. • Pesticide sprays drift and runoff are an entomofauna toxic exposure route. • Systemic pesticides have shown different behavior through buckwheat nectar. [ABSTRACT FROM AUTHOR]

Perennial wildflower strips (WFS) are known to have positive effects on wild bees in intensively used agricultural landscapes. Little knowledge exists, however, about the drivers of wild bee occurrence and if Red List species also profit from this agri-environmental scheme (AES). Therefore, we studied wild bees on transects along 20 four- to five-year-old WFS and in 10 cereal fields without AES (CONTROL sites) in differently structured landscapes across Saxony-Anhalt (Germany). In addition to local site parameters, we measured parameters of landscape structure in a 1 km radius of the WFS and CONTROL sites. The overall species richness of wild bees (125 species in total, 23 on average), including numerous specialist and Red List species, indicates a high attractiveness of perennial WFS sown with 30 native forbs. In CONTROL fields, 11 bee species (on average only one) were found. The species richness and abundance of wild bees were positively affected by local site conditions of the WFS and CONTROL sites, such as the overall number of sown and spontaneous forbs, the amount of flower rewards of sown forbs available to pollinators (Pollinator Feeding Index), and negatively by the cover of grasses. Therefore, seed mixtures of future AES should comprise a high diversity of wildflower species relevant as pollen sources for wild bees. The share of Red List wild bee species was strongly influenced by the landscape context and increased e.g. with Shannon landscape diversity and the availability of non-forest woody habitats and water bodies in the 1 km surroundings. These results suggest that besides the establishment of high-diversity WFS, semi-natural habitat structures have to be promoted to preserve rare wild bees especially in structurally simple agricultural landscapes. [Display omitted] • Wildflower mixtures with 30 native forbs attracted numerous common and rare wild bees. • Species richness and abundance of wild bees were mostly affected by WFS habitat quality. • Occurrence of red list wild bee species in WFS was influenced by landscape context. • WFS with high-diversity mixtures and semi-natural habitats should be promoted. [ABSTRACT FROM AUTHOR]

To counteract the rapidly ongoing species decline in modern agroecosystems, most European countries have developed and adopted agri-environment schemes. The efficiency of these schemes, however, ranges from successful to nearly ineffective. To estimate the efficiency of the Swiss agri-environment scheme in particular, we investigated the contribution of extensively managed pastures and meadows and wildflower areas to beetle, heteropteran bug and spider diversity. Extensively managed meadows were shown to contribute most to landscape-scale richness (highest species richness for beetles and bugs), followed by wildflower areas (bugs). Meadows harboured approximately twice as many beetle species unique to this habitat type than wildflower areas and pastures. Bug species unique to a specific habitat type were similar between meadows and wildflower areas, but much lower (approximately 30%) in pastures. To increase beetle species richness, extensively managed meadows should be represented more often in the landscape because meadows harboured the highest number of species and most uniquely found species. To increase species richness of true bugs, both meadows and wildflower areas should be represented more often in the landscape because they harboured more species and more uniquely found species compared to pastures. Across arthropod taxa and habitat types, β diversity was more important for γ diversity than α diversity, indicating that distinctiveness, rather than within-site diversity, was key in determining the contribution of sites to γ (landscape) diversity. This substantiates the argument that increasing the number of sites is efficient to increase landscape species richness. The turnover component of β diversity was far more important than the nestedness component for all arthropod taxa and habitat types and accounted for 79.0% to 95.4% of total β diversity. In conclusion, extensively managed meadows and wildflower areas should be particularly promoted by the Swiss agri-environment scheme, as they contributed more to landscape species richness and species uniqueness than pastures. [Display omitted] [ABSTRACT FROM AUTHOR]

Wildflower areas are a popular agri-environment scheme to counteract agro-biodiversity loss. Yet, their benefits are controversially discussed. Since inconsistent benefits may be owed to landscape context and temporal dynamics, we applied a multi-year study to unravel effects of permanent and transient habitats on ground-dwelling arthropods in wildflower areas and cereal fields. Across three consecutive years, we studied activity density, species richness and community composition of rove beetles, carabid beetles and spiders in ten pairs of wildflower areas and cereal fields along independent gradients of proportions of permanent semi-natural habitats or transient wildflower areas. Arthropod responses to the proportions of permanent semi-natural habitats often followed a hump-shaped pattern, whereas transient wildflower areas seemed to drive linear responses. An interactive effect on rove beetle richness in wildflower areas implies that benefits were highest either at intermediate proportions of permanent semi-natural habitats or at lower proportions, but with additional availability of transient wildflower areas or in landscapes with low proportions of permanent semi-natural habitats, but high proportions of wildflower areas. However, ground-dwelling arthropod activity density or species richness did not systematically increase over the three study years. Our results suggest that both permanent and transient habitats differ in how they affect biodiversity, possibly due to different temporal continuity and resource diversity. Benefits of permanent semi-natural habitats seemed highest at an equilibrium between an increasing resource-related species pool and an increasing diversity dilution, whereas benefits of transient wildflower areas seemed to increase with resource complementarity and connectivity at the landscape scale. Nevertheless, both habitats seem to complement each other and considered in concert, seem to be most effective in promoting benefits of wildflower areas to ground-dwelling arthropods at intermediate landscape complexity. The substantial variation in diversity patterns among years with weather extremes, suggests that optimizing benefits of wildflower areas requires further multi-year studies. [ABSTRACT FROM AUTHOR]

Farmland bird populations are in a deep crisis across Europe. Agri-environment schemes (AES) were implemented by the European Union to stop and reverse the general decline of biodiversity in agricultural landscapes. In Germany, flower strips are one of the most common AES. Establishing high-quality perennial wildflower strips (WFS) with species-rich native forb mixtures from regional seed propagation is a recent approach, for which the effectiveness for birds has not yet been sufficiently studied. We surveyed breeding birds and vegetation on 40 arable fields with WFS (20 with single and 20 with aggregated WFS) and 20 arable fields lacking WFS as controls across Saxony-Anhalt (Germany). Additionally, vegetation composition, WFS quantity and landscape structure (e.g. distance to nearest woody element) were considered in our analyses. All WFS were established with species-rich native seed mixtures (30 forbs) in agricultural practice as AES. Arable fields with WFS had a higher species richness and territory density of birds than controls, confirming the effectiveness of this AES. A forb-rich vegetation was the main driver promoting birds. Flower strip quantity at the landscape level had positive effects only on bird densities, but also single WFS achieved benefits. A short distance from WFS to woody elements increased total bird species richness. However, the density of farmland birds, which are target species of these AES, were negatively affected by the proximity and proportion of woody elements in the vicinity. The effect of the proportion of non-intensively used open habitats and overall habitat richness was unexpectedly low in the otherwise intensively farmed landscape. Species-rich perennial WFS significantly promoted breeding birds. Successful establishment of WFS, resulting in high-quality habitats, a high flower strip quantity as well as implementation in open landscapes were shown to maximise the effectiveness for restoring declining and AES target farmland birds. [Display omitted] [ABSTRACT FROM AUTHOR]

Sown wildflower areas are increasingly recommended as an agri-environmental intervention measure, but evidence for their success is limited to particular insect groups or hampered by the challenges of establishing seed mixes and maintaining flower abundance over time. We conducted a replicated experiment to establish wildflower areas to support insect pollinators in apple orchards. Over three years, and across 23 commercial UK orchards with and without sown wildflowers, we conducted 828 transect surveys across various non-crop habitats. We found that the abundance of flower-visiting solitary bees, bumblebees, honeybees, and beetles was increased in sown wildflower areas, compared with existing non-crop habitats in control orchards, from the second year following floral establishment. Abundance of hoverflies and other non-syrphid flies was increased in wildflower areas from the first year. Beyond the effect of wildflower areas, solitary bee abundance was also positively related to levels of floral cover in other local habitats within orchards, but neither local nor wider landscape-scale context affected abundance of other studied insect taxa within study orchards. There was a change in plant community composition on the sown wildflower areas between years, and in patterns of flowering within and between years, showing a succession from unsown weedy species towards a dominance of sown species over time. We discuss how the successful establishment of sown wildflower areas and delivery of benefits for different insect taxa relies on appropriate and reactive management practices as a key component of any such agri-environment scheme. [ABSTRACT FROM AUTHOR]

Wildflower strips (WFS) are amongst the most commonly applied measures to promote pollinators and natural enemies of crop pests in agroecosystems. Their potential to enhance these functionally important insect groups may vary substantially with time since establishment of WFS. However, knowledge on their temporal dynamics remains scarce, hampering recommendations for optimized design and management. We therefore examined temporal dynamics of taxonomic and functional groups of bees and hoverflies in perennial WFS ranging from one to ≥6 years since sowing with a standardized species-rich seed mixture of flowering plants in 18 agricultural landscapes in Switzerland. The abundance of wild bees, honeybees and hoverflies declined after the second year by 89%, 62% and 72%, respectively. Declines in bee abundance and hoverfly species richness were linear and those of aphidophagous hoverflies exponential, while wild bee species richness peaked in the third year. Declines over time generally paralleled decreases in flower abundance (-83%) and flowering species richness (-61%) and an increase in grass cover (+70%) in WFS. Flowering plant species richness showed strong positive relationships with dominant crop-visiting wild bees and aphidophagous hoverflies. Furthermore, dominant crop-visiting wild bees, but not aphidophagous hoverflies, were positively related to the proportion of (semi-)open semi-natural habitat in the surrounding landscape (500 m radius), but negatively with forest. We conclude that the effectiveness of perennial WFS to promote pollinator diversity, crop-pollinating bees and aphidophagous hoverflies through foraging resources decreases after the first two to three years, probably due to a decline of diverse and abundant floral resources. Although older perennial WFS may still provide valuable nesting and overwintering opportunities for pollinators and natural enemies, our findings indicate that regular re-sowing of perennial WFS may be necessary to maintain adequate floral resource provisioning for effective pollinator conservation and promotion of crop pollination and natural pest control services in agricultural landscapes. [ABSTRACT FROM AUTHOR]

Wildflower plantings are an important mitigation tool within agri-environmental schemes to counter insect decline in resource-scarce agricultural landscapes. Effectiveness of wildflower plantings for insect conservation is typically studied at the community or species level. It is the individual, however, that is subject to changing abiotic and biotic conditions, not the species per se. Accordingly, functional traits of individuals, i.e., the intraspecific functional diversity within species, likely mediate responses to wildflower resources and landscape context. Here we focused on the ecologically and economically important wild insect pollinator Bombus terrestris to study its intraspecific functional diversity and plant-pollinator individual interactions in wildflower plantings. We found considerable trait variation among flower-visiting B. terrestris workers. Locally, this variation could be attributed to flowering plant traits, with larger workers visiting larger inflorescences and individuals with longer tongues preferentially feeding on zygomorphic but not radially symmetrical flowers. In addition, wildflower plantings with high floral abundance attracted individuals with larger pollen baskets. At the landscape scale, increasing proportion of arable land resulted in smaller B. terrestris individuals in wildflower plantings, and a decrease in the overall size diversity of workers. These findings highlight the so far little considered role of intraspecific variation in functional traits of wild pollinators, which can mediate the trait-matching between plants and pollinator individuals. Landscape simplification from agriculture threatens intraspecific pollinator diversity, with potential harmful effects for pollinator fitness and plant reproduction. Tailored wildflower plantings can thus serve as an important tool to increase intraspecific variation in simplified landscapes. When designing seed mixtures for these plantings, high complementarity in plant traits is key for promoting high intraspecific trait diversity of bumblebees and potentially of other associated insect species. [ABSTRACT FROM AUTHOR]

Establishing wildflower strips has been suggested as an effective measure to promote pollination services, pest control or general insect biodiversity, but little is known about the integration of these different objectives when selecting flower seed mixtures. In ten agricultural landscapes in the Netherlands, we established a wildflower strip (0.4 – 4.9 ha) with half of each strip sown with a mixture targeting longer-tongued pollinators and the other half sown with a mixture targeting shorter-tongued pollinators and natural enemies. We determined establishment success of sown wildflowers and evaluated the attractiveness of the established flower communities to multiple functional groups of flower visitors: bumblebees (long-tongued pollinators), hoverflies (short-tongued pollinators and natural enemies), and butterflies and total flower-visitor richness (indicators of wider biodiversity values). Bumblebees clearly preferred the pollinator-targeted seed mixture and were positively associated with cover of Fabaceae and negatively with Apiaceae. Hoverflies consistently preferred the natural enemy mixture and were positively associated with Apiaceae. The other target groups displayed no clear responses to seed mixture type but instead were associated with local flower richness within strips. Across sites, responses of flower-visitors to sown mixture types did not depend on wildflower strip size, proportion of surrounding semi-natural habitat, or flower variables. However, all flower-visitors except butterflies increased with increasing established cover or richness of (sown) flower species across sites. Our results suggest that, although species-rich wildflower strips may benefit several species groups, maximising different objectives involves trade-offs between functional groups that prefer short- or long-corolla flowers. Furthermore, our study suggests that sowing a wildflower mixture does not necessarily result in a vegetation with the same composition as the seed mixture as species may establish poorly or not at all. Selection of flower species for seed mixtures should therefore, in addition to insect target group, take the establishment characteristics of plant species into account. [ABSTRACT FROM AUTHOR]

Designing wildflower habitats to support beneficial insects providing pollination and pest control services is important for supporting sustainable crop production. It is often desirable to support both groups of insects, making the selection of resource plants for insect conservation programs more challenging. Moreover, the process of selecting resource plants is complicated by the array of possible options in each region, and the need to provide resources over the entire growing season. Identifying traits shared by resource plants that are attractive to both bees and natural enemies can reduce the need to evaluate new plants in each region, by providing a guide for the types of plants expected to be rewarding to these insects. Using insect visitation data collected from replicated common garden plantings of native wildflower and shrub species from the Great Lakes region of the United States, we found a high degree of correlation between the abundance of bees and natural enemies visiting native plant species. These results were used to identify a set of 15 plant species that can provide resources for these insects throughout the summer. Across all tested species, pollen quantity per flower and the week of bloom were positively correlated with some, but not all, taxonomic groupings of beneficial insects. In contrast, floral area was consistently positively associated with visitation of both natural enemies and wild bees. This trait is easy to document and can allow for efficient local testing of potential resource plants, providing a faster path to implementing insect conservation in working landscapes. [ABSTRACT FROM AUTHOR]

Wildflower areas have become a staple tool within agro-environmental schemes (AES) to counteract pollinator declines. While their role in providing food resources to resident flower-visiting insects is unambiguous, the conservation effectiveness in a landscape context is less clear. Particularly, how multiple vs. single wildflower area utilization differs between simple and complex landscapes is understudied. We examined colonisation and community dynamics of wild bees and hoverflies in 33 newly established wildflower areas across a gradient of landscape complexity (amount of semi-natural habitat) and connectivity (presence of additional wildflower areas) for seven weeks during three consecutive years (one year during and two after establishment). We recorded more than 25% of the wild bee and hoverfly species of Hesse in an area of approx. 10 ha, substantiating the general benefit of wildflower areas to pollinators. While alpha-diversity increased with landscape complexity in isolated wildflower areas, the opposite pattern was observed for connected areas. The low alpha-diversity in complex landscapes indicated a dilution effect between connected sites. The inverse relationship between alpha and beta diversity among wildflower areas within landscapes suggests interspecific trade-offs between local resource conditions and landscape context. Accordingly, the establishment of multiple wildflower areas within AES is advisable to increase connectivity of suitable habitats in simple landscapes. Moreover, adjusting local conditions (plant diversity) to landscape context likely optimizes conservation effectiveness in modern agroecosystems. [ABSTRACT FROM AUTHOR]

Pollinators are declining rapidly, largely due to land conversion and intensification of agriculture. To mitigate their crisis, low-disturbance habitats, such as sown wildflower plantings, could promote pollinators by restoration of their resources. However, comprehensive knowledge is lacking on how landscape context, spatial configuration and age of wildflower plantings, seasonality and flower composition affect pollinator communities, especially from East-Central Europe. To understand these effects, we established diverse native wildflower plantings within heterogeneous and homogeneous agricultural landscapes, by two spatial configurations: one large field or three smaller strips, in Hungary. We sampled floral resources and wild pollinator insects (wild bees, hoverflies, butterflies), in early and mid-summer, for two years after establishment. Flower resources of the sown plant species increased continuously, and were complemented at high rate by flowering plant species from the soil seed bank, especially in the first year. Both flower abundance and diversity increased the abundance of pollinators, highlighting the important role of using diverse seed mixtures. Wild bee abundance and species richness increased year by year and season by season, while butterfly abundance also demonstrated a yearly increase after establishment. Hoverfly abundance and species richness, however, showed an opposite trend, possibly due to the inter-annual variation. Wild bee and butterfly abundance was higher in the heterogeneous than in the homogeneous landscapes. We did not observe any significant local effects of spatial configuration itself on pollinator populations. Wildflower plantings were particularly attractive for wild bees in flower-poor (homogeneous) landscapes during the flower-poor (mid-summer) period of the year. This can be explained by the increased contrast in flower resources between the wildflower plantings and the surrounding landscape, and highlights the importance of wildflower plantings in such conditions. Our results emphasise that to support pollinators effectively, future wildflower plantings should be maintained for multiple years, aim to maximise floral diversity and ensure continuously available flower resources throughout the entire season. They can be facilitated by i) using diverse seed mixtures of native flowering plants, ii) particularly focusing on plants that bloom during the crucial mid-summer period, iii) allowing the plant species to grow and bloom from the soil seed bank, and iv) using management techniques, which help to extend the flowering season. Further results from the upcoming years and similar long-term and landscape-scale experimental studies are needed to understand all the benefits and ecological processes of diverse native wildflower plantings especially in understudied European regions. • Sown native diverse wildflower plantings increased wild bee & butterfly abundance. • Plant species from the soil seed bank dominated flower resources in the first year. • Both flower abundance and species richness increased the abundance of pollinators. • Heterogeneous landscapes affected wild bee and butterfly abundance positively. • Plantings had special importance for wild bees in flower-poor seasons and landscapes. [ABSTRACT FROM AUTHOR]

• While global food production depends increasingly on pollinators, agricultural intensification causes their decline and limits productivity of pollinator dependent crops. • Pollinator loss can cause degradation of surrounding ecosystems causing further decrease of yields. • Climate change requires us to look beyond the plant and preserve the functioning of ecosystems. • Pollinators are key-agents for climate change adaptation of agro-ecosystems. • Farming with Alternative Pollinators (FAP) is a new low-cost approach for higher productivity of pollinator-dependent crops and climate resilient agro-ecosystems. Within global crop production 1961–2012, the share of pollinator independent crops increased twofold, but fourfold of pollinator dependent crops. Balanced diets within the boundaries of our planet require even more pollinator dependent crops. Particularly, Low and Middle Income Countries in the drylands produce pollinator dependent crops. However, climate change and agriculture increasingly cause risks for pollinators. Common reward-based seeding of wildflower strips is too expensive for these countries. Breeding towards pollinator independent crops might accelerate loss of pollinators. Recent publications warned that pollinator loss can reduce other ecosystem services supporting crop production. A new alternative approach called Farming with Alternative Pollinators (FAP) might fill the gap. FAP creates on-farm habitable conditions for pollinators and increases productivity and incomes per surface. [ABSTRACT FROM AUTHOR]

• Mutualistic interactions in pollination networks depend on the conservation of both pollinator and wildflower communities. • The botanical complexity of wildflower strips leads to a prolonged food availability for pollinators. • Some wildflower species were visited by a wide range of pollinators, while others were more selective. • The predominance of a chemical class of volatile implies the attraction for specific pollinators. • The choice of species in wildflower strips leads to differences in performance: diversified flowering periods and/or diversified attractiveness to pollinator species. The intensification of agricultural practices contributes to the decline of many taxa, such as insects and weeds. Wildflower species have an important environmental impact on rural biodiversity since plant-pollinator networks play a key role in both landscape aesthetics and environmental functionality. Due to their scarcity and/or disappearance in conventional agroecosystems, wildflowers are now being used in strips to restore the agro-environment. In this study, fifteen wildflower species were sown in order to verify their ecological performance in terms of a plant-pollinator interaction while in laboratory the several chemicals emitted by the flowers were identified. Flowering periods were concentrated in the spring, although flowering periods extended to the hot and dry summer months in some species. An extreme variability was found in terms of quantitative and qualitative pollinator-attractiveness (i.e., bees, bumblebees, hoverfly, bee flies and butterflies). Most wildflower species emit a volatiles belonging above all to one of the several chemical classes. A hierarchical cluster analysis of the different volatile emissions did not fully correlate with the botanical taxa of the respectives wildflowers. Often, single chemical compounds prevailed, such as β-ocimene and limonene among monoterpenes hydrocarbons, santolina alcohol in the case of oxygenated monoterpenes, or (Z) - or (E) -3-hexenol acetate for non-terpenes derivatives. It is believed that these chemical compounds can play an ecological role in plant-pollinator food webs. The hypothesis that the chemistry of the volatiles implies a specialized plant-pollinator co-evolution was confirmed by a significant regression (p < 0.05), which showed an inverse relationship between chemical diversity (H') and pollinator dominance (D) indexes. The chemical specificity indicates the specificity of pollinators and vice versa. [ABSTRACT FROM AUTHOR]

Wildflower strips are a management practice increasingly used to provide floral resources to wild bees in agroecosystems. Yet, despite known spatiotemporal variation in wild bee communities, the degree to which different wildflower strip species consistently support wild bee communities is poorly understood. Additionally, whether such consistency is related to the functional roles wildflower species play (e.g., in supporting diverse, rare, or unique suites of bee species) has not been considered. Over three years and on four diversified farms, we evaluated spatiotemporal variation in wild bee communities and bee-flower interactions in wildflower strips to better understand the roles of flower strip species in supporting bees. We documented spatiotemporal variation in the abundance, richness, and composition of local wild bee communities. Certain wildflower species consistently supported the highest richness of wild bees across years. These wildflower species were regularly core members of the bee-flower interaction network, visited by both generalist and specialist bees. By contrast, wildflower species supporting the most unique suites of bees were variable in this role among farms. In order to select plant species for wildflower strips that consistently support a high diversity of wild bee communities within farm landscapes, it is useful to consider several different functional roles that plants may play. Whereas a handful of wildflower species may be visited by the majority of local wild bee species, achieving support for the remaining, and perhaps rarer, bee species will require planting additional flower species, which may appear redundant until the spatiotemporal variation in wild bee communities is more thoroughly considered. This functional approach to selecting wildflower species for bee conservation efforts is important for making practical recommendations to land managers and for guiding best management practices in different regions and with diverse management goals. [ABSTRACT FROM AUTHOR]

Within the frame of the EU Common Agricultural Policy, most countries subsidise the establishment and maintenance of perennial flower strips on arable land within Agri-Environmental Schemes to provide foraging habitats and refuges for wildlife. In a replicated field experiment, we studied the effects of different types of seed mixtures on the establishment and maintenance of perennial flower strips on fertile arable land in the federal state of Saxony-Anhalt, Germany over seven years. The seed mixtures were commonly applied within recent Common Agricultural Policy funding periods: (1) a low-diversity cultivar standard seed mixture (CULTIVAR), (2) a high-diversity cultivar and native plant mixture (MIX), and (3) a high-diversity native plant mixture (WILDFLOWER). All plots were mulched every year in March and at the beginning of August. The low success of CULTIVAR triggered the massive encroachment of spontaneously established perennial grasses. In MIX, too, cultivars have disappeared after the first year. Both wildflower variants were successful in maintaining a high cover of sown perennial native forbs and a high ratio of established sown species, even after seven years. WILDFLOWER always tended to show better values than MIX. Furthermore, spontaneously establishing species began to spread their cover in MIX in the fifth year, with a very strongly increasing tendency, whereas in WILDFLOWER cover of spontaneously immigrating species stayed satisfyingly low. Using native wildflowers to establish perennial wildflower strips was very effective in maintaining high species diversity within the Agri-Environmental Schemes funding period of five years and beyond. WILDFLOWER was especially successful. On the other hand, CULTIVAR failed completely. On fertile soils in regions with rather low yearly precipitation, mulching twice a year supported the maintenance of perennial wildflower strips. [ABSTRACT FROM AUTHOR]

• Dry season affected plant growth, causing green roofs to be sources of CO 2. • Green roofs were sources of CO 2 and GWP, but sinks of CH 4 and N 2 O. • The main controls of GHG emissions were plant species and substrate depth. • The main control for substrate temperatures was substrate depth. • Irrigation mattered for temperatures and GHGs only in the hottest months. Covering building rooftops with vegetation [Green roofs (GRs)] holds promise for lowering building temperatures, reducing stormwater runoff, and providing other ecosystem services, but it is unclear how this will impact greenhouse gas (GHG) emissions. The latter may also be influenced by vegetation type, substrate depth, and irrigation regime and we sought to test this by comparing daytime GHG emissions (i.e., CH 4 , CO 2 , and N 2 O) and daily substrate temperatures in 48 GR microcosms in North-eastern Italy during a dry-hot summer season (June to September). Four vegetation types (Sedum mixture, cold season grasses, warm season grasses, or wildflowers), two substrate depths (8 cm or 14 cm), and two irrigation levels (1 or 2 mm d−1) were evaluated, for a total of 16 treatments with 3 replicates. We found that vegetation type had a significant effect on temperature [average temp. of 24.8 °C (Sedum) vs 25.5 °C (warm season grasses)] and CH 4 , CO 2 , and N 2 O emissions. While all vegetation types had net CO 2 emissions (median values from 147 to 671 mg m−2 h−1) and net N 2 O uptake (median values from -0.06 to -0.28 mg m−2 h−1), CH 4 flux had net negative values (capture) only in microcosms with wildflowers (-0.07 mg m−2 h−1), whereas other treatments had a median CH 4 emissions of 0.09 mg m−2 h−1. Substrate depth significantly affected CO 2 and N 2 O fluxes with deeper substrate leading to higher CO 2 emission (+ 60.7%) and greater N 2 O uptake (+ 30.8%). Irrigation level only significantly influenced N 2 O fluxes with 2 mm irrigation resulting in higher fluxes (-0.20 mg m−2 h−1) than 1 mm irrigation (-0.09 mg m−2 h−1). Our study suggests that under heat induced plant-stress conditions, GRs can improve N 2 O and CH 4 capture but might increase the emissions of CO 2 fixed by plants in the previous years in the substrate and that vegetation type and substrate depth can significantly alter emissions and are thus important design parameters. [ABSTRACT FROM AUTHOR]

Floral resources support several ecosystem services in agroecosystems, such as pollination or biological control. Many beneficial organisms feed on nectar or pollen for an important part of their life cycle. Providing adequate and sufficient floral resources through the conservation of spontaneous flowering vegetation may be a strategy to improve biological pest control. However, the role of spontaneous flowering plant species has mainly been evaluated in the recruitment of natural enemies. Cascading effects on pest regulation and damage reduction are rarely studied. Here we evaluated the effect of spontaneous flowering vegetation on pest regulation in 18 Mediterranean apple orchards. We focused on two main apple pests, Cydia pomonella and Dysaphis plantaginea , and on two groups of their natural enemies depending on floral resources: hoverflies and parasitoid wasps. We combined generalised linear mixed models and piecewise structural equation models to test for direct and indirect effects of spontaneous flowering plant species on beneficial insects (hoverflies, parasitoid wasps, wild bees and honeybees) and on pest regulation. We also tested for potential negative interactions between honeybees and hoverflies, parasitoid wasps or wild bees. There was a positive and significant effect of insect-pollinated flowers on hoverflies, parasitoid wasps and bees, but small cascading effects on D. plantaginea or C. pomonella density and associated damage. There was no significant relationship between honeybees and hoverflies, parasitoid wasps or wild bees. The reduction of D. plantaginea infestation was partially mediated by hoverfly abundance. Furthermore, we observed effects of spontaneous flowering vegetation on pest regulation and damage reduction independent of hoverfly and parasitoid wasp abundances. These results highlight the importance of conserving floral resources to support biological control of apple pests. Further studies are needed to better understand interactions between spontaneous flowering vegetation and crop management practices to promote sustainable pest regulation strategies. [Display omitted] • Wildflowers favoured bees, hoverflies and hymenopteran parasitoids in orchards. • Cascading effects of wildflowers on pest regulation via hoverflies and parasitoids were small. • Aphid infestation was reduced by hoverflies but not by hymenopteran parasitoids. • Wildflowers marginally reduced codling moth damage and aphid infestation. [ABSTRACT FROM AUTHOR]

Highlights • Perennial wildflower strips are valuable overwintering habitats for arthropods. • Distinct overwintering dynamics of arthropod taxa during flower strip succession. • Ploughing of annual wildflower strips reduces arthropod overwintering by 59%. • Ploughing reduced carabid and spider overwintering by 67% and 69%, respectively. • Annual ploughed wildflower strips may act as ecological trap for arthropods. Abstract Wildflower strips (WFS) are increasingly commonly adopted measures to promote biodiversity in agro-ecosystems. While their effectiveness in providing floral and other food resources for pollinators and natural enemies has been relatively well studied, much less is known about the value of different types of WFS as overwintering habitat for different functional arthropod groups. Here, we examined arthropod overwintering in WFS of different age compared to winter wheat fields. Moreover, we addressed the largely unexplored question to what extent non-permanent WFS may act as sink or ecological trap, if they attract high numbers of overwintering arthropods but only a low proportion of them survive and successfully emerge due to ploughing of strips during overwintering. Overwintering of all studied arthropod groups including potential pest natural enemies spiders, carabid beetles, staphylinid beetles and different families of pollinating flies was higher in WFS compared to winter wheat crops. Overwintering increased in WFS compared to wheat fields irrespective of WFS age, except for 4 year old WFS in the case of carabid beetles and 1 year old WFS in the case of spiders. While WFS age positively affected spider overwintering, numbers of overwintering pollinating flies and staphylinid beetles did not change significantly with WFS age. Moreover, carabid beetles tended to decline in the four years old WFS compared to younger ones. Ploughing of annual WFS during overwintering significantly reduced the number of successfully emerging arthropods by 59% on average. Detrimental effects were strongest for carabid beetles and spiders (reductions by 67% and 69%, respectively) to their numbers in ploughed WFS being similar to winter wheat fields. Reductions were less severe for pollinating flies and staphylinid beetles (both 47%), with higher numbers emerging from annual WFS compared to winter wheat fields even after ploughing of WFS. We conclude that perennial WFS are valuable overwintering habitats for a range of arthropod taxa across functional groups in arable cropping systems. Distinct responses of different arthropod taxa to WFS age highlight the importance of managing perennial WFS of various successional stages in order to promote overwintering of a broad variety arthropods in agro-ecosystems. Our study raises concerns, however, that annual WFS ploughed during the overwintering period are poor overwintering habitats for arthropods and may even act as ecological traps. [ABSTRACT FROM AUTHOR]

Abstract Managing the complex relationship between pollinators and their habitat requirements is of particular concern to growers of pollinator-dependent crop species, such as courgette (Cucurbita pepo). Naturally occurring wild flowers (i.e. agricultural weeds) offer a free, sustainable, and often underappreciated resource for pollinators, however, they may compete with crop flowers for visits. To understand the extent to which floral resources mediate pollinator visitation to courgette flowers and courgette fields, plant community and pollinator visitation data were collected at two spatial scales: field scale (in margins, and in the cropped area) and farm scale (500 m and 2000 m radii) for nine courgette fields across the UK. Apis mellifera (honeybees) and Bombus spp. (bumblebees) were the only pollinators observed to visit courgette flowers. Bumblebees were significantly more abundant on courgette flowers in fields with a greater species richness of wild flowers in the crop, whilst honeybees were significantly more abundant on courgette flowers in areas with less semi-natural habitat. For both honeybees and bumblebees, their abundance in field margins did not significantly reduce their abundance on courgette flowers, suggesting that wild flowers were not competing with courgette flowers for pollinator visitation. Although solitary bees were not observed to visit courgette flowers, their abundance and species richness in courgette fields were significantly greater with more semi-natural habitat and a greater species richness of wild flowers. Therefore, allowing uncultivated areas around the crop to be colonised by species-rich wild flowers is an effective way of boosting the abundance of bumblebees, which are important visitors to courgette flowers, as well as the abundance and species richness of solitary bees, thereby benefitting pollinator conservation. [ABSTRACT FROM AUTHOR]

Populations of wild insect pollinators such as bumble bees are threatened worldwide, which compromises pollinator-dependent crop yields. Intentionally planting wildflower patches in agricultural landscapes can support these populations and increase the pollination of nearby crops via the "spillover effect" (i.e., the exporter hypothesis), but may also distract bees from the crops and reduce their pollination via the "Circe principle" (i.e., the aggregation hypothesis). Considering the potentially high costs of these management strategies and the necessity to support wild insect pollinators in the Anthropocene, there is a pressing need to provide simulation tools that can inform best practices for wildflower plantings in agro-ecosystems. We developed a spatially implicit ordinary differential equations (ODEs) model specifically designed to determine the optimal wildflower-to-crop ratio as a function of wildflower patch (i) attractiveness, (ii) nutritional benefits, and (iii) blooming period relative to the crop. The model represents the population dynamics of a bumble bee colony and floral resources (crop and wildflower) in the landscape and nest during one harvesting season. We conduct a full factorial simulation experiment to identify the optimal characteristics of the wildflower patch (i.e., blooming period, attractiveness, relative abundance) that maximise crop yield via the enhancement of the number of bees pollinating crop flowers in a fictional blueberry farm. Our results suggest that providing highly attractive and nutritive wildflower resources before and not during the crop blooming season is the most beneficial strategy. When both flower types are in competition, pollination services can decrease, either when wildflowers are too attractive, or if they provide less benefits to the bees than the crop due to a trade-off between resources quality versus quantity. • We present an ODE model to inform wildflower plantings in blueberry crop fields. • It represents bumble bee colony dynamics as a function of landscape structure. • We conduct a full factorial experiment to find conditions that optimise crop yield. • Wildflowers that bloom prior and not during crop bloom benefits yield. • Both floral resource quantity and quality influence bee foraging choice and yield. [ABSTRACT FROM AUTHOR]

Flower strips are advocated as a strategy to promote beneficial insects as well as the services they deliver to adjacent crops. Flower strips have, however, often been developed separately for pollinators and natural enemies and, additionally, little consideration has been given to effects on insect herbivores. We sampled insect herbivores, their natural enemies and parasitism of pest eggs using vacuum sampling, sticky cards and egg cards in nine pairs of bee-attractive wildflower plantings and control field borders, as well as in adjacent tomato and watermelon crop fields in Yolo County, California 2015–2016. Control field borders had a higher total number of herbivores on sticky traps than did wildflower plantings, a pattern that was driven by more aphids, hoppers, psyllids and whiteflies, whereas wildflower plantings had more lace bugs and Lygus bugs. The total number of herbivores in the adjacent crop fields did not differ between treatments, but there were more leaf beetles near (at 10 m but not 50 m from) wildflower plantings. Control field borders had a higher total number of predators, driven by more big-eyed bugs, lady beetles and minute pirate bugs, whereas spiders were more common in wildflower plantings. The total number of predators in adjacent crop fields was, however, higher in those next to wildflower plantings, which was driven by more minute pirate bugs. Parasitoid wasps were more common in wildflower plantings and at 10 m but not 50 m into adjacent crop fields. Stink bug egg parasitism rate did not differ between treatments, either in the borders or in the crop fields. In conclusion, wildflower plantings clearly affect the insect herbivore and natural enemy community, but do so in a highly taxon-specific manner, which can lead to both positive and negative outcomes for pest control as a result. • Effects of wildflower plantings on herbivores and natural enemies were taxon-specific. • •Wildflower plantings promoted natural enemies in adjacent crop fields. • No consistent effect on herbivores and egg parasitism in adjacent crop fields. [ABSTRACT FROM AUTHOR]

Abstract The lack of examples of hybridisation within South African Cape Fynbos lineages gives the impression that interspecific hybridisation events may be rare in this system. If this is the case, then long-distance translocations of plant species across the Cape are unlikely to have any impact on the genetic component of biodiversity. Here we demonstrate that local populations of Protea eximia have hybridised with the non-local and introduced Protea susannae at Van Stadens Wildflower Reserve using morphological and genetic data; DNA sequence data were obtained from the internal transcribed spacer from the nuclear ribosomal cistron and a noncoding region of the chloroplast. Of the 24 plants from the reserve that were analysed, 11 were identified as hybrids, and comparing nuclear and chloroplast signals indicated bidirectional gene-flow between these species. This is the first study demonstrating the potential threat of long-distance dispersal in a Cape lineage to the genetic integrity of local populations. Highlights • Hybridisation is considered to be rare within Cape lineages. • We detected hybrids between local Protea eximia and introduced P. susannae. • Hybrids were common and widespread in the Van Stadens Wildflower Reserve. • Translocations may result in unexpected hybridisation. • This may represent a risk to the genetic integrity of local populations and species. [ABSTRACT FROM AUTHOR]

Highlights • We examined how seed respond to waterlogging induced by extreme precipitation. • Waterlogging significantly reduced seed size and see mass. • Tree species could respond to extreme weather by changing both seed morphological traits and element concentrations. Abstract Understanding how plant species respond to extreme climate events is crucial for planning management and conservation actions. As extreme precipitation accelerates, the waterlogging related to it is predicted to be more severe and frequent. To date, however, empirical studies addressing the effects of extreme precipitation-induced waterlogging on the seeds of wild plants are still scarce. In this study, we compared the size, mass and element concentration of seeds produced by non-inundated and inundated individuals of Sinojackia huangmeiensis , a critically endangered tree species with only one extant wild population. Compared to the seeds from non-inundated individuals, the seed length, seed width, and seed mass were all smaller for seeds from inundated individuals. However, the concentrations of four chemical elements in the seed displayed an opposite trend, except those elements (e.g., C, K, Ca, Mg, Al, Fe, Ni, B, Mo, and Cu) with no significant difference. Some toxic elements (e.g., Mn) accumulated in the seeds from inundated individuals, as well as some nucleic acid-protein elements (e.g., N and P) and enzymatic (e.g., Zn) elements. Our study provides rare empirical evidence that wild plants could respond to extreme precipitation-induced waterlogging by changing both seed morphological traits and element concentrations. [ABSTRACT FROM AUTHOR]

In intensive agricultural landscapes, decreased pollinator numbers have often been attributed to the loss of natural habitats. However, several studies show that certain mass flowering crops, such as oilseed rape (OSR), can alter the pattern of pollinator abundance at a field and landscape level. These studies have focused mainly on bees; information about the effect of OSR crops on other taxa is missing. We evaluated the abundance of bees and other (non-bee) flower visitors, and the fruit set of insect-pollinated target plants ( Raphanus sativus and Onobrychis viciifolia ) on the margins of OSR and cereal fields in landscapes with varying densities of non-cropped habitats (landscape structure). The presence of OSR crops and wildflower resources in field margins had varying effects on the abundance of bees and non-bee flower visitors. Bee abundance was enhanced by OSR crops, but decreased in complex landscapes. On the other hand, the abundance of non-bee flower visitors depended on the landscape structure, particularly on the location of cereal fields. Despite the numerous and diverse communities of pollinators attracted by OSR crops and wildflower resources, fruit set was enhanced only for generalist insect-pollinated plant species, because competition processes for pollinators affect specialist plant species. We conclude that the incorporation of OSR crops and maintenance of wildflower resources in agri-environmental schemes should be considered to improve the pollination services in agricultural landscapes highly dominated by cereal fields. [ABSTRACT FROM AUTHOR]

Wild flower diversity and abundance are strongly reduced in intensive agricultural landscapes. Flower-visiting insects may, therefore, experience limited nectar quantities and qualities. Adult insects that rely on energy-rich nectar income for flight, survival and reproduction are expected to be much more affected than insects that rely on their larval reserves. We dealt with this issue at the intraspecific level by comparing the responses of several life-history traits to different nectar diets between meadow brown butterflies ( Maniola jurtina ) originating from relative intensively managed and extensively managed agricultural landscapes. We used outdoor flight cages in which we simulated factorial treatments of low/high nectar quality and low/high quantity. Survival was highest in the high nectar quantity and quality treatment. Individuals from intensive landscapes were heavier, which is in line with predictions on increased capital breeding, and they survived better than those from extensive landscapes, of which the females lost body mass in all treatments. Females from intensive landscapes were able to buffer, or even increase, their body mass in the high nectar quantity treatments, but the differences with females from extensive landscapes disappeared under low nectar quantities (independent of nectar quality). In males, body mass losses were always larger for individuals from extensive landscapes compared to individuals from intensive landscapes. Forty percent of the females showed complete reproductive failure in the low quantity/low quality treatment compared to c . 7% in the other treatments. In the low quantity/low quality treatment, realized fecundity decreased strongly in females from intensive, but not extensive landscapes. Egg size was not affected by landscape of origin in the high-quality nectar treatments, but showed very different responses relative to landscape of origin in the treatments with low-quality nectar. Our results showed strong effects of reduced nectar supply on fitness-related traits, and responses were different between butterflies originating from landscapes with contrasted nectar diet. Hence, different levels of agricultural intensification changing the quantity and quality of the local nectar supply could pave the way for ecological differentiation of the organism’s behaviour, physiology and life history. [ABSTRACT FROM AUTHOR]

Populations of managed pollinators are often introduced in agricultural fields to increase pollination levels. Ideally, managed pollinators should show a strong affinity for the target crop, which depends on innate preferences, but also on the availability of alternative co-blooming flower resources. In this study we compared pollen collection in Osmia cornuta and Bombus terrestris populations introduced in orchards, and we analysed how it is affected by local and landscape floral context. Based on pollen preferences and foraging rates of the two species, we expected O. cornuta to collect more fruit tree pollen than B. terrestris and to be less influenced by landscape factors. We sampled 16 orchards of various fruit tree species (almonds, apricots, cherries, apples). In each orchard, we characterized local flower availability and landscape composition, and identified pollen samples from 20 to 30 individuals of each pollinator species. O. cornuta collected a greater proportion of fruit tree pollen than B. terrestris (92% vs 81%), irrespective of the availability of alternative flower resources at the local and landscape levels. The diversity of pollen collected by B. terrestris increased with the availability of alternative flower resources, both at the local and landscape levels, suggesting that some of the foraging by this species took place away from the target orchard. Our results demonstrate that wild flowers do not compete with fruit tree flowers for O. cornuta visitation. Therefore, the use of managed O. cornuta populations to supplement pollination services in orchards is compatible with the implementation of agri-environmental measures (flower strips, ecological focus areas) to promote wild pollinator communities. • Pollen collection by two managed orchard pollinators was analysed. • Osmia cornuta collected more fruit tree pollen than Bombus terrestris. • Pollen collection by O. cornuta was not affected by local or landscape factors. • Pollen diversity in B. terrestris depended on local and landscape factors. • Wildflowers may compete with orchard flowers for B. terrestris visitation. [ABSTRACT FROM AUTHOR]

Intensification of agriculture has been one of the major drivers for biodiversity loss in recent decades. Pollinators, which serve an important role in pollinating crops as well as wild plants, have shown a decline in species richness. Flower strips can be used to support pollinators in agro-ecosystems, however the question remains as to how their design can be optimized in order to best benefit pollinators. Increasing plant species diversity has been shown to be beneficial for pollinators, and it is often suggested that functional traits are driving this relationship. Therefore, increasing plant functional diversity could be a tool to support pollinator abundance and diversity. As experimental evidence on this relationship is scarce, we developed a field study with experimental sown flower strips with four functional diversity levels, based on multiple flower traits and with equal plant species richness. We monitored vegetation development, as well as the flower-visiting pollinator community and their interaction networks with flowers. We were able to create a functional diversity gradient while controlling for plant species richness and evenness. However, in contrast to our expectations, pollinator species richness and evenness were not influenced by functional diversity, and increasing functional diversity even resulted in lower flower visitation rates. Network stability metrics showed no effect or negative relationships with functional diversity. We conclude that increasing functional diversity was not the key for supporting pollinators in wildflower strips. Our results also suggest that, for a constant amount of flower resources, increasing plant functional diversity and thus decreasing redundancy of potential pollinator feeding niches, decreases the amount of flower resources present per feeding niche. As pollinator species tended to have less overlap in their feeding niches in flower strips with increased functional diversity, this may lead to a reduction of flower resources available for pollinator species with a more specialized feeding niche. [ABSTRACT FROM AUTHOR]

Ecological connectivity networks have been proposed as an efficient way to reconnect communities in fragmented landscapes. Yet few studies have evaluated if they are successful at enhancing actual functional connectivity (i.e. realized dispersal or gene flow) of focal species, or if this enhanced connectivity is enough to maintain genetic diversity and fitness of plant populations. Here we test the efficacy of an ecological connectivity network implemented in southern Germany since 1989 to reconnect calcareous grassland fragments through rotational shepherding. We genotyped 1449 individuals from 57 populations and measured fitness-related traits in 10 populations of Pulsatilla vulgaris , a flagship species of calcareous grasslands in Europe. We tested if the shepherding network explained functional connectivity in P . vulgaris and if higher connectivity translated to higher genetic diversity and fitness of populations. We found that population-specific F st was lowest in populations that had high connectivity within the shepherding network, and that well-connected populations within the network had significantly higher genetic diversity than ungrazed and more isolated grazed populations. Moreover, genetic diversity was significantly positively correlated with both seed set and seed mass. Together our results suggest that the implementation of an ecological shepherding network is an effective management measure to maintain functional connectivity and genetic diversity at the landscape scale for a calcareous grassland specialist. Populations with reduced genetic diversity would likely benefit from inclusion, or better integration into the ecological connectivity network. Our study demonstrates the often postulated but rarely tested sequence of positive associations between connectivity, genetic diversity, and fitness at the landscape scale, and provides a framework for testing the efficacy of ecological connectivity networks for focal species using molecular genetic tools. [ABSTRACT FROM AUTHOR]

Wildflowers have an important environmental impact on rural biodiversity. Their chromatic and shape evolution, to attract pollinators, is the key to their dual benefit in terms of aesthetics and environmental functionality. Their scarcity and/or disappearance in conventional agro-ecosystems have led them to be considered as necessary for the restoration of the agro-environment. We compared the dynamics of wildflower-only and wildflower-weed communities, in outdoor boxes, in order to study the floristic evolution over the course of a three-year experiment. Four agronomic treatments were applied: seeding time, late winter cutting, summer harrowing, summer cutting after senescence. Our hypothesis was that the sustainability of the wildflower community was vulnerable to strong weed interference and that agronomic management is necessary for the long-term survival of wildflowers. The indicators used were: biomass, number of seeds in the seed bank, diversity indexes. Our results showed that the growth of the wildflowers was affected by the weeds, in terms of the biomass and seed bank accumulated. However, various agronomic disturbances, such as cutting and, to a greater extent, harrowing, maintained the balance of the floristic complexity in the wildflower-weed community. The plant equilibrium was confirmed by the Shannon, Simpson and Evenness indexes. We found that long-term wildflower sustainability is closely linked to the agronomic management. Further studies are needed to optimize the anthropic-dependent survival of such wildflower buffer areas, given the “greening” measures encouraged by the new European agricultural policy aimed at biodiversity conservation. [ABSTRACT FROM AUTHOR]

In the present study, adsorption of methylene blue (MB) dye from aqueous solution on to a wild carrot flower activated carbon (WCFAC) as a potential adsorbent was investigated. No attempt has been made in the past on WCFAC and it also finds application in reducing the population of this poisonous weed. WCFAC was prepared using simple chemical activation method and MB dye adsorption was studied by batch adsorption experiments. The effects of various parameters like dosage effect, effect of pH, initial concentration of the dye and contact time on the adsorption capacity of MB dye on WCFAC are reported. It was found that, maximum adsorption (~88%) was observed at pH 6 with a good sorption capacity (~21 mg/g) of dye. The adsorption isotherms are analyzed by Langmuir and Freundlich models. The sorption data were better fitted by the Freundlich isotherm model as evident from the R2 value 0.940. Adsorption kinetics was performed and obeys pseudo-second-order kinetic model (R² at 0.9325). The zero point charge for the WCFAC was found to be 4.9 pH. pH optimization studies show that the favorable adsorption range ~4–6 pH. Experimental and kinetic results reveal that WCFAC is a potential adsorbent for the adsorption of MB dye from aqueous solution. [ABSTRACT FROM AUTHOR]

Restoring ecosystem services in agriculture is vital to reach a sustainable food production. More specifically, developing farming practices which enhance biological pest control is a main issue for today’s agriculture. The aim of this study was to assess whether the two strategies of complicating the search of host plants by pests by increasing plant diversity, and of supporting their natural enemies by managing habitats, could be combined simultaneously at the field scale to restore biological pest control and reduce chemical insecticide use. In Gembloux (Belgium), wildflower strips (WFS) were sown within wheat crops in which pests (i.e., aphids), their predators (i.e. aphidophagous hoverflies, lacewings and ladybeetles) and parasitoid wasps were monitored for 10 weeks in the period of May through July 2015 as indicators of the ES of pest control. Aphids were significantly reduced and adult hoverflies favoured in wheat in between WFS, compared to monoculture wheat plots. No significant differences were observed for adult lacewings, ladybeetles and parasitoids. In all treatments, very few lacewing and ladybeetle larvae were observed on wheat tillers. The abundance of hoverfly larvae was positively correlated with the aphid density on tillers in between WFS, showing that increasing food provisions by multiplying habitats within fields, and not only along margins, can help supporting aphidophagous hoverflies in crops. By enhancing the ecosystem services of biological pest control, this study shows that increasing both plant diversity and managing habitats for natural enemies may reduce aphid populations, hence insecticide use. Future research should continue this vein of work by quantifying the link between agricultural practices and the delivery of ecosystem services in order to guide future measures of agricultural policies. [ABSTRACT FROM AUTHOR]

There is a growing consensus that the world is facing a pollination crisis. To mitigate crop pollination deficits, some management strategies include the massive introduction of managed bee species, yet quite often they are applied blindly, as information on crop pollination effectiveness for each single pollinator species of assemblages is usually not available. Therefore, the introduction on managed species is not always the best option to improve crop yields. Here, by using the highly pollinator-dependent alfalfa crop (Medicago sativa L.) as a case study, we propose the use of the effectiveness landscape framework to identify key crop pollinator species. According to this framework, in a mutualistic interaction, each species´ effectiveness is represented by the product of a quantitative component and a qualitative one, these being measures of the outcomes of this interaction. We applied this framework for two managed and four wild bee species that visit alfalfa in fields southwest of Buenos Aires province, Argentina. We dissected the quantity components of the pollinator effectiveness landscape by estimating two quantitative subcomponents: visitation rate and flower tripping rate. Also, we estimate pod set as a qualitative component without dissecting it in subcomponents. Our results showed that the contribution of both components and the resulting pollinator effectiveness varied among pollinator species, indicating a contrasting effectiveness of different bee species on alfalfa pollination. For example, pollinator effectiveness was higher for managed than for wild bees, as consequence of their very high visitation rate, however, wild bee flower tripping rate and pod set were as high as managed ones. In fact, wild bees were more effective in promoting flower tripping than one of the managed bees (A. mellifera). This approach allowed us to assess which effectiveness components and subcomponents make pollinator species more or less effective, thus providing valuable information to identify key species to be enhanced to help in closing yield gaps. We suggest that the application of the effectiveness landscape framework would be useful to develop strategies to improve crop pollination service in pollinator-dependent crop systems. • Identification of key crop pollinator species is essential. • Effectiveness landscape decomposes effectiveness into components and subcomponents. • Effectiveness landscape allows us to assess the effectiveness of each crop pollinator species. • This approach is useful for crop pollination management strategies. [ABSTRACT FROM AUTHOR]

The availability of diverse floral resources is crucial for the maintenance of pollinating insects and the pollination service they provide in agricultural landscapes. Ensuring plant diversity is thus essential for the maintenance and even restoration of pollinator communities. Many studies have highlighted the beneficial effects for pollinating insects of the floral resources provided either by uncultivated plants in agroecological infrastructures such as hedgerows and in crop fields, or by the addition of cultivated flowers through intercropping. However, the role of these different co-occurring vegetation types in providing floral resources to wild flower-visiting insects remains unexplored simultaneously, especially regarding their potential interacting effects. Using a paired design sampling approach, we investigated the contribution of floral resources provided by hedgerows, weeds in crop fields, and legumes intercropped with winter cereals, and their interacting effects, to the abundance of different groups of wild flower-visiting insects, plant-insect interactions and insect preferences. Our results show that the abundance of most groups of floral visitors were enhanced by the cover or species richness of floral resources provided by hedgerows or by weeds in crop fields. Interactions between uncultivated plants and insects were driven by the presence of some particular 'preferred' plant species offering either abundant, accessible or high-quality floral resources. By contrast, abundance of floral visitors was not enhanced by the addition of legume flowers through intercropping. The positive effects of flowering wild plants in hedgerows and crop fields remained mostly unchanged in the presence of intercrops, because of the limited contribution of legumes in providing attractive floral resources to floral visitors. Our results highlight the critical role of floral resources provided by weeds in crop fields for diverse flower-visiting insects, in addition to the floral resources provided by hedgerows. We recommend that agri-environment schemes should promote a wide diversity of floral resources at field margins through the retention of existing semi-natural elements or the sowing of wildflower mixtures. More importantly, our study encourages the seeking of alternative forms of weed management, which support a trade-off between the maintenance of pollinating insects and pollination service provision on the one hand, and crop yields and incomes for farmers on the other. • Uncultivated floral resources in hedgerows and crop fields enhance wild flower-visiting insects. • Cover of legume floral resources is less beneficial for floral visitors. • Beneficial effects of uncultivated resources do not vary according the presence of intercrops. • Diversification strategies should rely on uncultivated plants in field and field margins. [ABSTRACT FROM AUTHOR]

The biodiversity restoration of the agroecosystem through wildflower strips is one of the most important agronomic strategies of the last few decades. However, poor knowledge of the bio-agronomic characteristics of the various wildflower species often leads to suboptimal performances especially as a result of their poor seed germination and poor seedling emergence due to the erratic soil texture. A two-year experiment involving the sowing of eighteen wildflower species in different texture conditions highlighted how some species emerged earlier or more effectively than others and verifying the consequent ecosystem service provided to pollinators. Species with smaller seeds were more inhibited by sowing in soil with high content of clay. Additionally, an inverse relationship (Boltzmann's sigmoidal regression) was found between seed weight and soil-mediated inhibition. This soil-mediated inhibition was higher in the clayey textured soil, showing that this inhibition was mediated both by seed weight and by the clay particles of the soil. The reciprocal interference between the emerged seedlings also determined a further decline in the wildflower species with small seeds. This differing agronomic performance, after sowing in the two different soil textures, did not affect the number of pollinator visits. Performance differed both in terms of floristic biodiversity and pollinator biodiversity. Finally, the experiment highlighted the importance of the appropriate selection of the wildflower species for biodiversity restoration - not only in terms of pollen and nectar availability for pollinators, but also in terms of compatibility with the soil texture in which the wildflower seeds are sown. • The sowing of wildflower strips is effective in enhancing agroecosystem biodiversity. • Soil texture strongly affects the agronomic performance of the selected wildflower mixtures. • Clay hinders germination and seedling emergence of species with small and light seeds. • Clay soils reduce the emergence of small-seed species, thus reducing the biodiversity of both plants and pollinators. • The choice of wildflower mixtures according to the soil texture will optimize biodiversity restoration. [ABSTRACT FROM AUTHOR]

Insect pollinators are declining globally as a result of the anthropogenic pressures that have destroyed native habitats and eroded ecosystems. These declines have been associated with agricultural productivity losses, threatening food security. Efforts to restore habitat for pollinators are underway, emphasizing large-scale habitat creation like wildflower strips, yet ignoring the impact of smaller or more isolated patch-creation. A meta-analysis of 31 independent published studies assessed the effect of scale of pollinator planting interventions (herbaceous strips, hedgerows, fertiliser/grazing/mowing control). We assessed pollinator species richness and abundance against size of intervention and type. Pollinator conservation interventions increased species richness and abundance in almost all of the studies examined, with the greatest increases in pollinator ecological metrics seen from hedgerows covering 40 m² and herbaceous interventions at 500 m². We then analysed results from a 5-year study that deployed small pollinator habitats (30 m²) at community gardens and farms (<150,000 m²) practicing organic methods in the Pacific Northwest US. Small additions to pollinator resources had a significant local impact on pollinator abundance, but this effect was lost when these relatively small additions were introduced to sites in larger landscapes (>150,000 m²). Together, we show that small interventions (∼500 m²) can significantly benefit pollinators, but only when sufficiently densely distributed at a landscape level. Though we understand the effects of single interventions at various scales, future research is needed to understand how these relatively small interventions act cumulatively at a landscape scale, and within this context whether larger areas are still needed for some species. Nonetheless, these preliminary data are promising, and may play an important role in convincing smaller landowners to act to preserve insect pollinators. • Pollinator conservation approaches are driven by governmental policy and local land manager uptake. • Most research ignores smaller scale approaches to restore pollinator communities. • Meta-analysis of small interventions shows the greatest impact on pollinators abundance happens at 432m². • Interventions on farms were also studied, the positive effect of these small interventions decrease over larger farm sizes. • Smaller interventions are more practical and may be easier to encourage wider uptake from smaller entities. [ABSTRACT FROM AUTHOR]

• The salt tolerance threshold of lilium pumilum was preliminarily determined. • L. pumilum roots and leaves play a more important role in ion transport under salt stress. • Transcriptome analysis was performed on the leaves and roots of L. pumilum treated with salt stress. • The response mechanism of L. pumilum to salt stress is tissue-specific and involves different genes. • Plant hormone signal transduction, starch and sucrose metabolism, MAPK signaling pathway-plant, ion regulation and TFs are key pathways for L. pumilum to respond to salt stress. Salt stress seriously affects the growth and development of plants. Most species of lilies are not salt tolerant, thus salt affecting their geographical application. As a wild flower, Lilium pumilum is an excellent breeding material because of its bright colors, strong salt tolerance and cold tolerance. There are few studies on the salt tolerance mechanism and salt tolerance gene mining of L. pumilum. In this study, the salt tolerance threshold of L. pumilum was determined to be approximately 150 mM and the abundant ion translocation occurs in roots and leaves at the concentration. RNA-seq was used to characterize the transcriptome differences between L. pumilum leaves and roots treated with 150 mM NaCl for 2 and 12 h. By de novo assembly, 47,763 and 76,871 unigenes were identified in L. pumilum leaves and roots, respectively. Differentially expressed genes in leaves were higher than those in roots at 2 h, whereas the opposite result was obtained at 12 h. GO analysis of DEGs showed that transcriptional regulation and redox processes were significantly enriched, and KEGG annotation indicated that L. pumilum roots and leaves responded to salt stress mainly through phytohormone signaling, MAPK signaling pathways, and starch and sucrose metabolism. These results reveal important salt stress-related genes and metabolic pathways in L. pumilum , providing valuable information for exploring the salt tolerance mechanism of L. pumilum , screening salt tolerance genes and breeding new salt-tolerant L. pumilum varieties. [ABSTRACT FROM AUTHOR]

Three different honey samples viz. longan flower, lychee flower and wildflower honeys were collected from Northern Thailand and subjected to conventional thermal (90 °C/5 min) and ultrasound (40% and 80% amplitudes/20 kHz/30 min) treatments. The physicochemical characterizations such as color parameters, browning index (BI), pH, viscosity, diastase activity, 5-hydroxymethylfurfural (HMF) content and antioxidative properties affected by processing treatments were determined. Our results illustrated that both thermal and ultrasonic processes sufficiently eliminated the indicator microbes to the complied limits of the Thai Agricultural Standard (TAS 8003-2013). Based on the results, the color, BI, pH, diastase activity and HMF content of ultrasonicated honeys were minimally altered. Ultrasonication yielded higher quality of antioxidant compounds and properties as compared to the conventional thermal technique. Additionally, ultrasound treatment at 40% amplitude noticeably improved the levels of total phenols, total flavonoids and antioxidant capacity (FRAP assay). Thus, ultrasonication, especially with low amplification, is an alternative preservation technique for maintaining the quality of honey samples. [ABSTRACT FROM AUTHOR]

One goal of wildflower plantings is to promote biodiversity in intensively managed agricultural landscapes. Flower visitors of wildflower plantings encompass many ecologically and economically important species. However, most studies on flower visitors of wildflower plantings have focused on single or few prominent taxa (e.g., wild bees and hoverflies). In contrast, it remains largely unresolved how non-prominent flower visitors of the community are affected by wildflower resources, landscape context and time of the flowering season. We studied highly diverse flower-visitor communities on 14 wildflower plantings varying in flower abundance and richness and their surrounding landscape context within a 500 m radius (percentage arable land, presence of additional wildflower plantings). Flower visitors were sampled in the early (May–June) and late (June–July) flowering season and grouped as follows: managed honeybees, wild bees, hoverflies, all other flower visitors. Strikingly, only 81 (25.1%) of all 322 visiting species (<50.0% of individuals) were bees or hoverflies, and 241 non-prominent ‘other’ visitor taxa were sampled, encompassing many ecologically and economically important species, e.g., parasitic wasps and non-syrphid Diptera. With the exception of honeybee abundance that was positively related to flower abundance, flower abundance and richness of wildflower plantings affected neither abundance nor richness of any visitor group. While a high amount of surrounding arable land decreased species richness of wild bees, richness of all other groups was unaffected. In contrast to the relatively weak abundance and richness responses at the group-level, we found strong species-specific responses to landscape context, resulting in substantial spatial and temporal turnover in community composition. In the early flowering season, wildflower plantings that were accompanied by additional local plantings and embedded within complex landscapes supported the highest abundances of habitat specialists (e.g. Bombus spp.), whereas isolated plantings were predominantly visited by agricultural generalists (e.g. predatory hoverflies and pollen beetles). These compositional differences diminished towards the end of the flowering season. Our study highlights the great conservation potential of wildflower plantings in agricultural landscapes. With the exception of wild bees, wildflower plantings support a high diversity of functionally complementary flower-visitor species from complex to structurally simple agricultural landscapes. These so-far overlooked flower visitors may have the potential to provide complementary ecosystem services and to step-in in agricultural settings where prominent providers have been lost. Assessments of the value of wildflower plantings to biodiversity conservation and agriculture require a shift away from solely focusing on prominent taxa and towards a more holistic appreciation of the entire flower-visitor community. [ABSTRACT FROM AUTHOR]

There is an increasing need for the landscape conservation of the threatened biodiversity of coastal ecosystems. This work studies the seed ecology (germination, dormancy, self-burial, seedlings emergence and seed bank disposition) of various Mediterranean hind dune wildflowers in a perspective of landscape protection and restoration. The deep dormancy of most species (overall Fabaceae, Brassicaceae and Calystegia soldanella ) was eliminated or reduced after some seed treatments selected to simulate some natural events (washing, cold stratification, scarification, etc ). “ In situ ” seed bank analysis was carried out by collecting sand samples in different dune ecosystems of Tuscany and Sardinia. Indeed the seed vertical distribution plays a crucial role in the germination dynamics on buried seeds. The vertical distribution of the seed bank of 20 selected species was confined to the upper 0–12 cm layer of sand dune. Their burial depth was found to be inversely related to the 1000 seed weight of the different species ranging by 0.01 g of Centaurium maritimum to 47.58 of C. soldanella . Roughly 80% of the seed bank is accumulated in the shallowest sand layer (0–3 cm) and the only very little seeds of C. maritimum and Silene colorata were capable to reach the deeper layer of 9–12 cm. Seedling emergence from increasing burial depth has been studied in pots “ ex situ ”. In spite of the respective seed dormancy-breaking treatments, their germination was progressively inhibited by burial depth increasing in the sand matrix. Calculation of the depth able to halve emergence established an inverse relationship between seed weight and depth-mediated inhibition. In addition, the ex situ capacity for self-burial (mediated by winter rains), ranging between 1 and 3.5 cm, showed a similar, but inverse, relationship between seed weight and self-burial performance. Seed bank of herbaceous perennial species appears to be a good indicator of an ecosystem's health and the perspective of environmental restoration, by using native wildflowers, should be carried out by sowing treated seeds, with a light burial, behind the natural or artificial foredunes. [ABSTRACT FROM AUTHOR]

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Sown wildflower strips should promote the species diversity of several insect groups in order to be an effective tool for the compensation of biodiversity loss in agricultural environments. We studied the responses of two herbivorous insect groups, Heteroptera (true bugs) and Auchenorrhyncha (leafhoppers), to the properties of wildflower strips in a three-year (2008–2010) study in southern Finland. The experiment was replicated in six reed canary grass fields. The insect groups showed opposite responses; the abundance of Auchenorrhyncha was lower while the abundance and species richness of Heteroptera was higher in wildflower than control strips. During succession, both species richness and abundance of Auchenorrhyncha increased unlike Heteroptera. This difference could largely be explained by dietary differences. Auchenorrhyncha, including several grass feeders, could not take advantage of the increasing dicot species richness like Heteroptera species. This was also a likely reason for the unexpected finding that only Heteroptera species richness depended on the placement of the strip, being higher near field margins than in mid-field. We conclude that the optimal planning and implementation of wildflower strips call for the definition of clear goals, the knowledge of the requirements of target species as well as considering the cropping system involved. [ABSTRACT FROM AUTHOR]

Management that enhances floral resources can be an effective way to support pollinators and pollination services. Some wildlife-friendly farming schemes aim to enhance the density and diversity of floral resources in non-crop habitats on farms, whilst managing crop fields intensively. Others, such as organic farming, aim to support ecological processes within both crop and non-crop habitats. How effective these different approaches are for supporting pollination services at the farm scale is unknown. We compared organic farming with two non-organic wildlife-friendly farming schemes: one prescriptive (Conservation Grade, CG) and one flexible (Entry Level Stewardship, ELS), and sampled a representative selection of crop and non-crop habitats. We investigated the spatial distribution and overall level of: (i) flower density and diversity, (ii) pollinator density and diversity and (iii) pollination services provided to Californian poppy ( Eschscholzia californica ) potted phytometer plants. Organic crop habitats supported a higher density of flowers, insect-wildflower visits, and fruit set of phytometers than CG or ELS crop habitats. Non-crop habitats supported a higher density of flowers and insect-flower visits than crop habitats on CG and ELS farms. Pollination services were higher on organic farms overall compared to CG or ELS. Pollinator diversity and density did not differ between schemes, at the point or farm level. CG farms received the highest total number of insect-wildflower visits. The findings support organic farming practices that increase floral resources in crop habitats, such as sowing clover or reduced herbicide usage, as mechanisms to enhance pollination services. However trade-offs with other ecosystem services are likely and these are discussed. The findings support the CG scheme as a way of supporting pollinators within farms where high wheat yields are required. [ABSTRACT FROM AUTHOR]

The effectiveness of agri-environment schemes (AES) such as wildflower strips in promoting farmland biodiversity has been relatively well studied. Their effects on biodiversity-mediated ecosystem services, such as natural pest control, in contrast, remain poorly evaluated and their consequences on crop yield largely unexplored. We assessed the effect of sown, species-rich, perennial wildflower strips, promoted through the Swiss AES, on pest control services and their consequences for crop yield in nearby winter wheat. We found strong reductions in cereal leaf beetle Oulema sp. (CLB) density (eggs: 44%, larvae: 66%) and crop damage (40%) caused by CLB in winter wheat besides wildflower strips ( N = 10) compared with control fields without wildflower strip ( N = 10). Moreover, average crop yield was increased by 10% in winter wheat next to wildflower strips up to 10 m into the fields. Wheat yield was positively associated with broad leaved plant cover, flower density and diversity of nearby flower strips, yet collinearity with wheat density made these effects difficult to disentangle. Our study demonstrates that diverse wildflower strips with known benefits for farmland biodiversity can also promote biological pest control and crop yield. This creates a win-win situation for crop production and biodiversity conservation, through which such AES may contribute to ecological intensification. [ABSTRACT FROM AUTHOR]

There is considerable and ongoing debate as to the harm inflicted on bees by exposure to agricultural pesticides. In part, the lack of consensus reflects a shortage of information on field-realistic levels of exposure. Here, we quantify concentrations of neonicotinoid insecticides and fungicides in the pollen of oilseed rape, and in pollen of wildflowers growing near arable fields. We then compare this to concentrations of these pesticides found in pollen collected by honey bees and in pollen and adult bees sampled from bumble bee colonies placed on arable farms. We also compared this with levels found in bumble bee colonies placed in urban areas. Pollen of oilseed rape was heavily contaminated with a broad range of pesticides, as was the pollen of wildflowers growing nearby. Consequently, pollen collected by both bee species also contained a wide range of pesticides, notably including the fungicides carbendazim, boscalid, flusilazole, metconazole, tebuconazole and trifloxystrobin and the neonicotinoids thiamethoxam, thiacloprid and imidacloprid. In bumble bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations up to 73 nanogram/gram (ng/g). It is notable that pollen collected by bumble bees in rural areas contained high levels of the neonicotinoids thiamethoxam (mean 18 ng/g) and thiacloprid (mean 2.9 ng/g), along with a range of fungicides, some of which are known to act synergistically with neonicotinoids. Pesticide exposure of bumble bee colonies in urban areas was much lower than in rural areas. Understanding the effects of simultaneous exposure of bees to complex mixtures of pesticides remains a major challenge. [ABSTRACT FROM AUTHOR]