Exploring the relationships between landscape complexity, wild bee species richness and reproduction, and pollination services along a complexity gradient in the Netherlands

AbstractPollinator refuges such as wildflower strips are planted on farms with the goals of mitigating wild pollinator declines and promoting crop pollination services. It is unclear, however, whether or how these goals are impacted by managed honey bee (Apis mellifera L.) hives on farms. We examined how wildflower strips and honey bee hives and/or their interaction influence wild bee communities and the fruit count of two pollinator-dependent crops across 21 farms in the Mid-Atlantic U.S. Although wild bee species richness increased with bloom density within wildflower strips, populations did not differ significantly between farms with and without them whereas fruit counts in both crops increased on farms with wildflower strips during one of 2 years. By contrast, wild bee abundance decreased by 48%, species richness by 20%, and strawberry fruit count by 18% across all farm with honey bee hives regardless of wildflower strip presence, and winter squash fruit count was consistently lower on farms with wildflower strips with hives as well. This work demonstrates that honey bee hives could detrimentally affect fruit count and wild bee populations on farms, and that benefits conferred by wildflower strips might not offset these negative impacts. Keeping honey bee hives on farms with wildflower strips could reduce conservation and pollination services.

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Improving Habitat Quality at the Local and Landscape Scales Increases Wild Bee Assemblages and Associated Pollination Services in Apple Orchards in China

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.621469 ◽

2021 ◽

Vol 9 ◽

Author(s):

Panlong Wu ◽

Piaopiao Dai ◽

Meina Wang ◽

Sijie Feng ◽

Aruhan Olhnuud ◽

...

Keyword(s):

Management Practices ◽

Ground Cover ◽

Agricultural Landscapes ◽

Wild Bees ◽

Natural Habitats ◽

Pollination Services ◽

Wild Bee ◽

Wide Range ◽

Bee Diversity ◽

Landscape Scales

Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.

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Wild Bee Toxicity Data for Pesticide Risk Assessments

Data ◽

10.3390/data4030098 ◽

2019 ◽

Vol 4 (3) ◽

pp. 98 ◽

Cited By ~ 2

Author(s):

Kathleen A Lewis ◽

John Tzilivakis

Keyword(s):

Risk Assessment ◽

Dietary Exposure ◽

Risk Assessments ◽

Toxicity Data ◽

Wild Bees ◽

Pollination Services ◽

Wild Bee ◽

Long Time ◽

Pollinating Insects ◽

Regulatory Risk Assessment

Pollination services are vital for agriculture, food security and biodiversity. Although many insect species provide pollination services, honeybees are thought to be the major provider of this service to agriculture. However, the importance of wild bees in this respect should not be overlooked. Whilst regulatory risk assessment processes have, for a long time, included that for pollinators, using honeybees (Apis mellifera) as a protective surrogate, there are concerns that this approach may not be sufficiently adequate particularly because of global declines in pollinating insects. Consequently, risk assessments are now being expanded to include wild bee species such as bumblebees (Bombus spp.) and solitary bees (Osmia spp.). However, toxicity data for these species is scarce and are absent from the main pesticide reference resources. The aim of the study described here was to collate data relating to the acute toxicity of pesticides to wild bee species (both topical and dietary exposure) from published regulatory documents and peer reviewed literature, and to incorporate this into one of the main online resources for pesticide risk assessment data: The Pesticide Properties Database, thus ensuring that the data is maintained and continuously kept up to date. The outcome of this study is a dataset collated from 316 regulatory and peer reviewed articles that contains 178 records covering 120 different pesticides and their variants which includes 142 records for bumblebees and a further 115 records for other wild bee species.

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Organic Establishment of Pollination Reservoirs in the Lowbush Blueberry (Ericales: Ericaceae) Agroecosystem

Open Agriculture ◽

10.1515/opag-2018-0044 ◽

2018 ◽

Vol 3 (1) ◽

pp. 393-403 ◽

Cited By ~ 3

Author(s):

E. M. Venturini ◽

F. A. Drummond ◽

A. K. Hoshide

Keyword(s):

Economic Analysis ◽

Coniferous Forest ◽

Cropping System ◽

Bee Pollination ◽

Pollination Services ◽

Wild Bee ◽

Lowbush Blueberry ◽

Native Bee ◽

Wild Blueberries ◽

Nurse Crops

Abstract Pollination reservoirs are pollen and nectar rich wildflower plantings intended to enhance pollination services in pollinator-dependent crops. Despite government assistance, plantings often fail to establish. Our focal crop, wild blueberries, is a unique cropping-system native to the U.S.A. It is never planted or cultivated, and typically exists in isolated fields within a mostly coniferous forest matrix. Our study takes place in Maine, U.S.A., where growers could economically benefit by switching reliance from rented honey bees to native bee pollination. Lowbush blueberry growers support wild bee enhancement efforts, but the low pH (4.0-5.0) of this agro-ecosystem presents unique challenges to wildflower establishment. We sought to identify methods that Organic certified growers can use to successfully establish pollination reservoirs in this system. We tested the effects of nurse crops and mowing on the success of a custom wildflower mixture over four years. Success was considered in terms of longevity, sown species diversity, above-ground biomass, and the number and weight of inflorescences. The authors present an economic analysis of cost versus projected planting longevity. In the fourth year of establishment, sown plant diversity significantly decreased, Solidago spp. weeds became dominant, and treatments were not a strong determinant of planting success. The economic analysis suggests that the high cost of pollination reservoir establishment may be a barrier to grower adoption. This study provides evidence and economic justification that weeds must be controlled prior to planting and represents one of the first studies to empirically test organic strategies for wildflower establishment in an agricultural context.

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Pollination services for apple are dependent on diverse wild bee communities

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2016.01.004 ◽

2016 ◽

Vol 221 ◽

pp. 1-7 ◽

Cited By ~ 50

Author(s):

Eleanor J. Blitzer ◽

Jason Gibbs ◽

Mia G. Park ◽

Bryan N. Danforth

Keyword(s):

Pollination Services ◽

Wild Bee ◽

Bee Communities

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Wild Bee Conservation within Urban Gardens and Nurseries: Effects of Local and Landscape Management

Sustainability ◽

10.3390/su12010293 ◽

2019 ◽

Vol 12 (1) ◽

pp. 293 ◽

Cited By ~ 4

Author(s):

Monika Egerer ◽

Jacob Cecala ◽

Hamutahl Cohen

Keyword(s):

Species Richness ◽

Land Cover ◽

Plant Species ◽

Crop Production ◽

Plant Production ◽

Native Plant ◽

Landscape Features ◽

Wild Bee ◽

Bee Conservation ◽

Local Habitat

Across urban environments, vegetated habitats provide refuge for biodiversity. Gardens (designed for food crop production) and nurseries (designed for ornamental plant production) are both urban agricultural habitats characterized by high plant species richness but may vary in their ability to support wild pollinators, particularly bees. In gardens, pollinators are valued for crop production. In nurseries, ornamental plants rarely require pollination; thus, the potential of nurseries to support pollinators has not been examined. We asked how these habitats vary in their ability to support wild bees, and what habitat features relate to this variability. In 19 gardens and 11 nurseries in California, USA, we compared how local habitat and landscape features affected wild bee species abundance and richness. To assess local features, we estimated floral richness and measured ground cover as proxies for food and nesting resources, respectively. To assess landscape features, we measured impervious land cover surrounding each site. Our analyses showed that differences in floral richness, local habitat size, and the amount of urban land cover impacted garden wild bee species richness. In nurseries, floral richness and the proportion of native plant species impacted wild bee abundance and richness. We suggest management guidelines for supporting wild pollinators in both habitats.

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Changes in the Summer Wild Bee Community Following a Bark Beetle Outbreak in a Douglas-fir Forest

Environmental Entomology ◽

10.1093/ee/nvaa119 ◽

2020 ◽

Vol 49 (6) ◽

pp. 1437-1448 ◽

Cited By ~ 1

Author(s):

Gabriel G Foote ◽

Nathaniel E Foote ◽

Justin B Runyon ◽

Darrell W Ross ◽

Christopher J Fettig

Keyword(s):

United States ◽

Species Richness ◽

Bark Beetle ◽

Tree Mortality ◽

Canopy Cover ◽

Douglas Fir ◽

Wild Bee ◽

Bee Community ◽

Bee Communities ◽

Bee Abundance

Abstract The status of wild bees has received increased interest following recent estimates of large-scale declines in their abundances across the United States. However, basic information is limited regarding the factors affecting wild bee communities in temperate coniferous forest ecosystems. To assess the early responses of bees to bark beetle disturbance, we sampled the bee community of a Douglas-fir, Pseudotsuga menziesii (Mirb.), forest in western Idaho, United States during a Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae), outbreak beginning in summer 2016. We resampled the area in summer 2018 following reductions in forest canopy cover resulting from mortality of dominant and codominant Douglas-fir. Overall, results from rarefaction analyses indicated significant increases in bee diversity (Shannon’s H) in 2018 compared to 2016. Results from ANOVA also showed significant increases in bee abundance and diversity in 2018 compared to 2016. Poisson regression analyses revealed percent tree mortality from Douglas-fir beetle was positively correlated with increases in total bee abundance and species richness, where community response variables displayed a cubic trend with percent tree mortality. Percent reduction in canopy cover from 2016 to 2018 was also correlated with bee species richness and diversity. These findings suggest that wild bee communities may benefit from changes in forest structure following bark beetle outbreaks.

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Wild Bee Visitation Rates Exceed Pollination Thresholds in Commercial Cucurbita Agroecosystems

Journal of Economic Entomology ◽

10.1093/jee/toz295 ◽

2019 ◽

Vol 113 (2) ◽

pp. 562-574 ◽

Cited By ~ 4

Author(s):

C M McGrady ◽

R Troyer ◽

S J Fleischer

Keyword(s):

Management Strategies ◽

Field Size ◽

Bee Pollination ◽

Wild Bees ◽

Temporal And Spatial Variation ◽

Pollination Services ◽

Wild Bee ◽

Visitation Rates ◽

Field Edge ◽

Temporal And Spatial

Abstract Wild bees supply sufficient pollination in Cucurbita agroecosystems in certain settings; however, some growers continue to stock fields with managed pollinators due to uncertainties of temporal and spatial variation on pollination services supplied by wild bees. Here, we evaluate wild bee pollination activity in wholesale, commercial pumpkin fields over 3 yr. We identified 37 species of bees foraging in commercial pumpkin fields. Honey bees (Apis mellifera L. [Hymenoptera: Apidae]), squash bees (Eucera (Peponapis) Say, Dorchin [Hymenoptera: Apidae]), and bumble bees (Bombus spp., primarily B. impatiens Cresson [Hymenoptera: Apidae]) were the most active pollinator taxa, responsible for over 95% of all pollination visits. Preference for female flowers decreased as distance from field edge increased for several bee taxa. Visitation rates from one key pollinator was negatively affected by field size. Visitation rates for multiple taxa exhibited a curvilinear response as the growing season progressed and responded positively to increasing floral density. We synthesized existing literature to estimate minimum ‘pollination thresholds’ per taxa and determined that each of the most active pollinator taxa exceeded these thresholds independently. Under current conditions, renting honey bee hives may be superfluous in this system. These results can aid growers when executing pollination management strategies and further highlights the importance of monitoring and conserving wild pollinator populations.

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