Toward functional pollinator abundance and diversity: Comparing policy response for neonicotinoid use to demonstrate a need for cautious and well-planned policy

Abstract Governmental agri-environment schemes (AES) aim to improve pollinator abundance and diversity on farmland by sowing wildflower seed mixes. These often contain high proportions of Fabaceae, particularly Trifolium (clovers), which are attractive to some bumblebee species, but not to most of the ~ 240 solitary bee species in the UK. Here we identify wildflowers that are attractive to a greater range of wild bee species. Forty-five wildflower species being farmed for commercial seed production on a single farm were surveyed for native bees. Bee walks were conducted through discrete wildflower areas from April until August in 2018. The results indicate that including a range of Apiaceae, Asteraceae, and Geraniaceae in seed mixes would cater for a wide diversity of bee species. A total of 14 wildflower species across nine families attracted 37 out of the 40 bee species recorded on the farm, and accounted for 99.7% of all visitations. Only two of these 14 species are included in current AES pollinator mixes. Unexpectedly, few visits were made by bumblebees to Trifolium spp. (0.5%), despite their being considered an important food source for bumblebees, while Anthyllis vulneraria and Geranium pratense were highly attractive. For solitary bees, Crepis capillaris, Sinapsis arvensis, Convolvulus arvensis and Chaerophyllum temulum were amongst the best performing species, none of which are usually included in sown flower mixes. We suggest that the standard ‘pollinator’ mixes used in AES might be updated to include some of these wildflower species, and trialled as seed mixes on farmland.

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The potential of electricity transmission corridors in forested areas as bumblebee habitat

Royal Society Open Science ◽

10.1098/rsos.160525 ◽

2016 ◽

Vol 3 (11) ◽

pp. 160525 ◽

Cited By ~ 12

Author(s):

Bruce Hill ◽

Ignasi Bartomeus

Keyword(s):

Transmission Lines ◽

Plant Density ◽

Current Management ◽

Electricity Transmission ◽

Main Determinant ◽

Pollinator Abundance ◽

Management Regime ◽

Natural Grasslands ◽

Forested Areas ◽

Abundance And Diversity

Declines in pollinator abundance and diversity are not only a conservation issue, but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumblebees ( Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at 10 sites across Sweden's Uppland region. Our results show that transmission corridors have no impact on bumblebee diversity in the surrounding area. However, transmission corridors and other maintained habitats such as roadsides have a level of bumblebee abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumblebee habitat, but given that host plant density is the main determinant of bumblebee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumblebee conservation and the ecosystem services they provide.

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“Farming with Alternative Pollinators” approach increases pollinator abundance and diversity in faba bean fields

Journal of Insect Conservation ◽

10.1007/s10841-021-00351-6 ◽

2021 ◽

Author(s):

Ahlam Sentil ◽

Patrick Lhomme ◽

Denis Michez ◽

Sara Reverté ◽

Pierre Rasmont ◽

...

Keyword(s):

Faba Bean ◽

Cultivated Plants ◽

Pollinator Decline ◽

Flower Visitor ◽

North West ◽

Pollinator Abundance ◽

Main Crop ◽

Abundance And Diversity ◽

Habitat Enhancement ◽

The Impact

AbstractPollinators are threatened worldwide and strategies and measures to support their conservation are proliferating. Among them, the approach “Farming with Alternative Pollinators” (FAP) aims to support pollinators by seeding strips of pollinator-attracting cultivated plants surrounding the crops, and simultaneously providing income to the farmer. In this study we assessed whether this approach supports pollinator diversity in agro-ecosystems and increases flower visitor diversity and abundance in faba bean fields in north-west Morocco. We tested the impact of FAP using a variety of marketable habitat enhancement plants (MHEP): flax, coriander, arugula, chia and canola. A total of 62 pollinator species were recorded, among which almost half of them are new records for the region. Most wild pollinators recorded in faba bean were digger bees (genus Anthophora) and long-horn bees (genus Eucera). MHEP shared diverse flower visitors with faba bean and hosted diverse pollinator groups that did not meet their food requirements from the main crop. The FAP approach highly increased flower visitor abundance and diversity in the whole FAP fields, however it did not generate significant pollinator spillover towards the main crop. Implications for insect conservation: our results show that the FAP approach is an effective approach to mitigate pollinator decline in agro-ecosystems.

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Flower Strips in Wheat Intercropping System: Effect on Pollinator Abundance and Diversity in Belgium

Insects ◽

10.3390/insects9030114 ◽

2018 ◽

Vol 9 (3) ◽

pp. 114 ◽

Cited By ~ 4

Author(s):

Clara Amy ◽

Grégoire Noël ◽

Séverin Hatt ◽

Roel Uyttenbroeck ◽

Frank Van de Meutter ◽

...

Keyword(s):

Insect Pests ◽

Triticum Aestivum L ◽

Agricultural Landscapes ◽

Agricultural Systems ◽

System Effect ◽

Pollinator Abundance ◽

Pollinator Species ◽

Pollinator Community ◽

Abundance And Diversity ◽

Agricultural Areas

The decline of pollinators in agricultural areas has been observed for some decades, this being partly due to landscape simplification in intensive agrosystems. Diversifying agricultural landscapes by sowing flower strips within fields could reduce these adverse effects on biodiversity. In this context, the study presented here aimed at assessing and comparing the abundance and diversity of bees (Hymenoptera: Anthophila) and hoverflies (Diptera: Syrphidae) found and visiting flowers in three types of flower strips in Belgium: (i) a mixture of 11 wild flowers, (ii) a monofloral strip of Dimorphoteca pluvialis (Asteraceae) and (iii) a monofloral strip of Camelina sativa (Brassicaceae), where the last two are considered to be intercrops since they are valuable on the market, all sown within a field of winter wheat (Triticum aestivum L.). Pollinators were captured with pan traps and by netting in standardised transects from May to July 2017. One-thousand one-hundred and eighty-four individuals belonging to 43 bee species and 18 hoverfly species were collected. Significant differences in hoverfly diversity were found between the different flower strips. The multifloral treatment supported a greater diversity of syrphid species. Various pollinator species visited the different flowers composing the mixture and also D. pluvialis. The pollinator community proved to be predominantly generalist, with the exception of an oligolectic species in Belgium, Andrena nitidiuscula. Moreover, the three tested flower strips were effective in attracting hoverflies, among them natural enemies of insect pests. This study opens new perspectives in the design of intercropping systems with flower strips towards the design of sustainable agro-ecosystems. Improving economic profitability of sowing flower strips could encourage farmers to diversify their agricultural systems and foster conservation biology strategies.

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Pollinators on Cowpea Vigna unguiculata: Implications for Intercropping to Enhance Biodiversity

Insects ◽

10.3390/insects12010054 ◽

2021 ◽

Vol 12 (1) ◽

pp. 54

Author(s):

Beatrice N. Dingha ◽

Louis E. Jackai ◽

Barbara A. Amoah ◽

Clement Akotsen-Mensah

Keyword(s):

Honey Bees ◽

Sampling Methods ◽

Farming Systems ◽

Sticky Traps ◽

Pollinator Abundance ◽

Carpenter Bees ◽

Cowpea Varieties ◽

Abundance And Diversity ◽

The Relationship ◽

Pan Traps

Pollinators are on the decline and loss of flower resources play a major role. This raises concerns regarding production of insect-pollinated crops and therefore food security. There is urgency to mitigate the decline through creation of farming systems that encourage flower-rich habitats. Cowpea is a crop that produces pollen and nectar attractive to pollinators. Twenty-four cowpea varieties were planted, and the number of pollinators were counted using three sampling methods: pan traps, sticky traps, and direct visual counts. Five pollinator types (honey bees, bumble bees, carpenter bees, wasps, and butterflies and moths), 11 and 16 pollinator families were recorded from direct visual counts, pan and sticky traps, respectively. Pollinator distribution varied significantly among varieties and sampling methods, with highest number on Penny Rile (546.0 ± 38.6) and lowest (214.8 ± 29.2) in Iron and Clay. Sticky traps accounted for 45%, direct visual counts (31%), and pan traps (23%) of pollinators. Pollinators captured by pan traps were more diverse than the other methods. The relationship between number of pollinators and number of flowers was significant (r2 = 0.3; p = 0.009). Cowpea can increase resources for pollinators and could be used to improve pollinator abundance and diversity in different farming systems.

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DIVERSITY AND ABUNDANCE OF NATIVE BEE POLLINATORS ON BERRY CROPS AND NATURAL VEGETATION IN THE LOWER FRASER VALLEY, BRITISH COLUMBIA

The Canadian Entomologist ◽

10.4039/ent116965-7 ◽

1984 ◽

Vol 116 (7) ◽

pp. 965-974 ◽

Cited By ~ 20

Author(s):

Kenna E. MacKenzie ◽

Mark L. Winston

Keyword(s):

Honey Bees ◽

Habitat Destruction ◽

Natural Vegetation ◽

Cultivated Plants ◽

Native Bees ◽

Pollinator Abundance ◽

Native Bee ◽

Berry Crops ◽

Abundance And Diversity ◽

Fraser Valley

AbstractNative bee pollinators were collected and observed on cultivated blueberry, raspberry, and cranberry and on natural non-cultivated plants such as blackberry, buttercup, fireweed, thistle, and hairy cat's ear. Higher abundance and diversity of native bees were found on natural vegetation than on berry crops. Native bee populations on berry crops increased from 1981 to 1982, although diversity was similar. Native bees were not abundant enough to ensure adequate pollination of berry crops, and therefore, the use of managed honey bees is advisable. Pesticide impact, competition with managed honey bees, and habitat destruction have probably decreased native bee populations in agricultural areas of the Fraser Valley.The use of a standard measure of native pollinator abundance, bees observed/min/m2, is recommended for future studies of this kind.

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Effects of grazing intensity on pollinator abundance and diversity, and on pollination services

Ecological Entomology ◽

10.1111/een.12310 ◽

2016 ◽

Vol 41 (4) ◽

pp. 400-412 ◽

Cited By ~ 22

Author(s):

AMPARO LÁZARO ◽

THOMAS TSCHEULIN ◽

JELLE DEVALEZ ◽

GEORGIOS NAKAS ◽

THEODORA PETANIDOU

Keyword(s):

Grazing Intensity ◽

Pollination Services ◽

Pollinator Abundance ◽

Abundance And Diversity

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Supporting Bees in Cities: How Bees Are Influenced by Local and Landscape Features

Insects ◽

10.3390/insects12020128 ◽

2021 ◽

Vol 12 (2) ◽

pp. 128

Author(s):

Anthony C. Ayers ◽

Sandra M. Rehan

Keyword(s):

Phylogenetic Diversity ◽

Negative Impact ◽

Functional Trait ◽

Green Spaces ◽

Landscape Features ◽

Pollinator Abundance ◽

Cavity Nesting ◽

Abundance And Diversity ◽

Variable Influence ◽

Urban Matrix

Urbanization is a major anthropogenic driver of decline for ecologically and economically important taxa including bees. Despite their generally negative impact on pollinators, cities can display a surprising degree of biodiversity compared to other landscapes. The pollinating communities found within these environments, however, tend to be filtered by interacting local and landscape features that comprise the urban matrix. Landscape and local features exert variable influence on pollinators within and across taxa, which ultimately affects community composition in such a way that contributes to functional trait homogenization and reduced phylogenetic diversity. Although previous results are not easily generalizable, bees and pollinators displaying functional trait characteristics such as polylectic diet, cavity-nesting behavior, and later emergence appear most abundant across different examined cities. To preserve particularly vulnerable species, most notably specialists that have become underrepresented within city communities, green spaces like parks and urban gardens have been examined as potential refuges. Such spaces are scattered across the urban matrix and vary in pollinator resource availability. Therefore, ensuring such spaces are optimized for pollinators is imperative. This review examines how urban features affect pollinators in addition to ways these green spaces can be manipulated to promote greater pollinator abundance and diversity.

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The potential of electricity transmission corridors in forested areas as bumble bee habitat

10.1101/027078 ◽

2015 ◽

Author(s):

Bruce Hill ◽

Ignasi Bartomeus

Keyword(s):

Transmission Lines ◽

Plant Density ◽

Bumble Bees ◽

Bumble Bee ◽

Electricity Transmission ◽

Pollinator Abundance ◽

Management Regime ◽

Natural Grasslands ◽

Bee Conservation ◽

Abundance And Diversity

AbstractDeclines in pollinator abundance and diversity are not only a conservation issue but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumble bees (Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at ten sites across Sweden’s Uppland region. Our results show that transmission corridors have no impact on bumble bee diversity in the surrounding area. However, transmission corridors and other maintained habitats have a level of bumble bees abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumble bee habitat, but given that host plant density is the main determinant of bumble bee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumble bee conservation and the ecosystem services they provide.

Download Full-text