Pollination is a critical ecosystem service underpinning the productivity of agricultural systems across the world. Wild insect populations provide a substantial contribution to the productivity of many crops and seed set of wild flowers. However, large-scale evidence on species-specific trends among wild pollinators are lacking. Here we show substantial inter-specific variation in pollinator trends, based on occupancy models for 353 wild bee and hoverfly species in Great Britain between 1980 and 2013. Furthermore, we estimate a net loss of over 2.7 million occupied 1 km2 grid cells across all species. Declines in pollinator evenness suggest that losses were concentrated in rare species. In addition, losses linked to specific habitats were identified, with a 55% decline among species associated with uplands. This contrasts with dominant crop pollinators, which increased by 12%, potentially in response agri-environment measures. The general declines highlight a fundamental deterioration in both wider biodiversity and non-crop pollination services.

Summary1. Declines in abundance and diversity of bumble bees ( Bombus spp.) in Europe have been linked to agricultural intensification and the resulting loss of suitable foraging and nesting habitats. Environmental Stewardship (ES) is a new scheme in England offering the opportunity to restore habitats of value for these important pollinators to agricultural land. Scientific evaluation of the options prescribed within the scheme is essential to ensure that their objectives are met and that the benefits can be realized by the full bumble bee species assemblage. 2. We compared the efficacy of different ES options for field margins on arable land in enhancing the abundance and diversity of flowering resources and foraging bumble bees. Our study was conducted over 3 years using a multisite experiment. 3. Overall, uncropped margins sown with mixtures containing nectar and pollenproducing plants were more effective in providing bumble bee forage than margins sown with a grass mix, allowed to regenerate naturally or managed as conservation headlands. 4. A mixture of agricultural legumes established quickly and attracted on average the highest total abundance and diversity of bumble bees, including the rare long-tongued species Bombus ruderatus and Bombus muscorum . However, marked differences were observed between species and sexes in their responses to field margin management over time. 5. A diverse mixture of native wildflowers attracted more of the shorter-tongued Bombus spp. and provided greater continuity of forage resources, especially early in the season. Allowing Cirsium spp. to flower on such margins also increased their attractiveness to male bumble bees. 6. Synthesis and applications . Our results suggest that the legume-based 'pollen and nectar flower mix', as prescribed under Entry Level Stewardship in England, can quickly provide a highly attractive forage resource for bumble bees, but that issues of seasonal flowering phenology and longevity of the mixture need to be addressed. Establishment of 'floristically enhanced margins' under Higher Level Stewardship will be important to provide diverse perennial communities of forage plants and to support a greater range of Bombus spp. and other pollinators. The population-level responses of bumble bees to introduced seed mixtures and other agri-environment options require further study in order to maximize the benefits of such schemes in intensively farmed landscapes.

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S.. 2017. Bumblebee family lineage survival is enhanced in high-quality landscapes. Nature, 543 (7646). 547-549. 10.1038/nature21709Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. 1Bumblebee family lineage survival is enhanced in high quality landscapes Main textThe loss of semi-natural habitats and floral resources within intensively managed agricultural landscapes has been identified as a major driver of declines in insect pollinators 3,9,10 , with negative consequences for crop pollination 11 . Habitat restoration (e.g. the planting of flowering hedgerows, meadows or flower strips along field margins under agri-environment schemes 12 )can mitigate these effects, increasing local pollinator abundance and species richness 13-15 and enhancing rates of persistence and colonization at the community level 16 . However, we lack understanding of the effects of restoration on key aspects of pollinator biology that may explain the mechanisms behind these responses. In particular, improving habitat quality might be expected to enhance the prospects of successful reproduction and between-year survival in targeted areas, but whether this occurs is unknown.3 Bumblebees (Bombus spp.) are key pollinators of wild flowers and commercial crops 17,18 .Following a eusocial, annual colony cycle, new queens enter hibernation in the autumn and emerge in spring to search for a nest site and found a colony. Each colony may produce up to several hundred 'daughter' workers, which forage from spring to summer at flowers for nectar and pollen to rear new daughter queens and males 19 . The survival and dispersal patterns of bumblebee queens during hibernation and nest-searching periods are critical to overall population persistence, but remain undescribed in wild populations 8,20,21 . In addition, although the availability of floral resources within foraging distance of the nest has been shown to increase numbers of workers and males produced per colony, effects on queen production have been less clear 22 and there is no evidence regarding how queen production, survival and dispersal may be linked with underlying habitat quality and land-use 23 .Here, we investigated the effects of habitat quality and land-use on bumblebee survival and dispersal between colony cycle stages across two years. We first tested whether colonies located within or near high-value foraging habitats had a greater probability of producing daughter queens that survive the winter hibernation and spring emergence stages, henceforth termed 'family lineage survival'. Second, we tested whether the distances travelled by queens between hibernation and nest-searching periods (as a measure of minimum relative queen dispersal distances within our study landscape) were affected by the proportion of high quality habitat surrounding their natal colony. We sampled DNA non-lethally from...

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Abstract. The global decline of insect pollinators, especially bees, is cause for concern, and there is an urgent need for cost-effective conservation measures in agricultural landscapes. While landscape context and habitat quality are known to influence species richness and abundance of bees, there is a lack of evidence from manipulative field experiments on bees' responses to adaptive management across differently structured landscapes. We present the results of a large-scale study that investigated the effects of a targeted agri-environment scheme (AES) on bumble bees (Bombus spp.) over three years in the United Kingdom. Forage patches of different sizes were sown with a conservation flower mixture across eight sites covering a broad range of agricultural land use types. Species richness and worker densities (especially of the longer-tongued Bombus species for which the mixture was targeted) were significantly higher on sown forage patches than on existing non-crop control habitats throughout the three-year study, but the strength of this response depended on both the proportions of arable land and abundance of herbaceous forb species in the surrounding landscape. The size of sown patches also affected worker density, with smaller patches (0.25 ha) attracting higher densities of some species than larger patches (1.0 ha). Our models show that a targeted AES can deliver greater net benefits in more intensively farmed areas, in terms of the number and species richness of bumble bees supported, than in heterogeneous landscapes where other foraging habitats exist. These findings serve to strengthen the evidence base for extending agri-environment schemes to boost declining pollinator populations to a larger number of agricultural landscapes across the globe.

The status of pollinating insects is of international concern, but knowledge of the magnitude and extent of declines is limited by a lack of systematic monitoring. Standardized protocols are urgently needed, alongside a better understanding of how different methods and recorders (data collectors) influence estimates of pollinator abundance and diversity. We compared two common methods for sampling wild pollinating insects (solitary bees, bumblebees and hoverflies), pan traps and transects, in surveys of 1 km countryside squares (agricultural and semi‐natural habitats) and flowering crop fields across Great Britain, including the influence of local floral resources (nectar sugar availability or crop flower density) on the insects sampled. Further, we compared the performance of recorders with differing expertise (non‐specialist research staff, taxonomic experts and non‐expert volunteers) in applying methods. Pan traps and transects produced compositionally distinct samples of pollinator communities. In the wider countryside, pan traps sampled more species of solitary bee and hoverfly. In flowering crops, transects recorded a greater number of individual bumblebees, but fewer species. Across all taxonomic groups and countryside and crop samples, transects generally had lower rates of species accumulation per individual collected than pan traps. This demonstrates that differences between methods in estimating richness are not due to sampling effort alone. However, recorders possessing greater taxonomic expertise can produce species accumulation data from transects that are almost commensurate with pan trapping. The abundance and species richness of pollinators (except solitary bees) on transects in the wider countryside was positively related to the availability of estimated nectar sugar. In crops, pollinator abundance responses to flower densities were idiosyncratic according to crop type, but overall the response was positive and negative for transects and pan traps, respectively. Given these taxonomic and context‐specific differences in method performance, we assess their suitability for monitoring pollinating insect communities and pollination services. We discuss the relevance of these findings within the context of achieving standardized, large‐scale monitoring of pollinating insects.