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Grüter C, Segers FHID, Hayes L. Extensive loss of forage diversity in social bees owing to flower constancy in simulated environments. Proc Biol Sci 2024; 291:20241036. [PMID: 39082242 PMCID: PMC11289734 DOI: 10.1098/rspb.2024.1036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 08/02/2024] Open
Abstract
Many bees visit just one flower species during a foraging trip, i.e. they show flower constancy. Flower constancy is important for plant reproduction but it could lead to an unbalanced diet, especially in biodiversity-depleted landscapes. It is assumed that flower constancy does not reduce dietary diversity in social bees, such as honeybees or bumblebees, but this has not yet been tested. We used computer simulations to investigate the effects of flower constancy on colony diet in plant species-rich and species-poor landscapes. We also explored if communication about food sources, which is used by many social bees, further reduces forage diversity. Our simulations reveal an extensive loss of forage diversity owing to flower constancy in both species-rich and species-poor environments. Small flower-constant colonies often discovered only 30-50% of all available plant species, thereby increasing the risk of nutritional deficiencies. Communication often interacted with flower constancy to reduce forage diversity further. Finally, we found that food source clustering, but not habitat fragmentation impaired dietary diversity. These findings highlight the nutritional challenges flower-constant bees face in different landscapes and they can aid in the design of measures to increase forage diversity and improve bee nutrition in human-modified landscapes.
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Affiliation(s)
- Christoph Grüter
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, BristolBS8 1TQ, UK
| | | | - Lucy Hayes
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, BristolBS8 1TQ, UK
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2
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Maccaro JJ, Figueroa LL, McFrederick QS. From pollen to putrid: Comparative metagenomics reveals how microbiomes support dietary specialization in vulture bees. Mol Ecol 2024; 33:e17421. [PMID: 38828760 DOI: 10.1111/mec.17421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/12/2024] [Accepted: 05/20/2024] [Indexed: 06/05/2024]
Abstract
For most animals, the microbiome is key for nutrition and pathogen defence, and is often shaped by diet. Corbiculate bees, including honey bees, bumble bees, and stingless bees, share a core microbiome that has been shaped, at least in part, by the challenges associated with pollen digestion. However, three species of stingless bees deviate from the general rule of bees obtaining their protein exclusively from pollen (obligate pollinivores) and instead consume carrion as their sole protein source (obligate necrophages) or consume both pollen and carrion (facultative necrophages). These three life histories can provide missing insights into microbiome evolution associated with extreme dietary transitions. Here, we investigate, via shotgun metagenomics, the functionality of the microbiome across three bee diet types: obligate pollinivory, obligate necrophagy, and facultative necrophagy. We find distinct differences in microbiome composition and gene functional profiles between the diet types. Obligate necrophages and pollinivores have more specialized microbes, whereas facultative necrophages have a diversity of environmental microbes associated with several dietary niches. Our study suggests that necrophagous bee microbiomes may have evolved to overcome cellular stress and microbial competition associated with carrion. We hypothesize that the microbiome evolved social phenotypes, such as biofilms, that protect the bees from opportunistic pathogens present on carcasses, allowing them to overcome novel nutritional challenges. Whether specific microbes enabled diet shifts or diet shifts occurred first and microbial evolution followed requires further research to disentangle. Nonetheless, we find that necrophagous microbiomes, vertebrate and invertebrate alike, have functional commonalities regardless of their taxonomy.
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Affiliation(s)
- Jessica J Maccaro
- Department of Entomology, University of California Riverside, Riverside, California, USA
| | - Laura L Figueroa
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Quinn S McFrederick
- Department of Entomology, University of California Riverside, Riverside, California, USA
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3
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Tarbill GL, White AM, Sollmann R. Response of pollinator taxa to fire is consistent with historic fire regimes in the Sierra Nevada and mediated through floral richness †. Ecol Evol 2023; 13:e10761. [PMID: 38107425 PMCID: PMC10721959 DOI: 10.1002/ece3.10761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/12/2023] [Accepted: 11/11/2023] [Indexed: 12/19/2023] Open
Abstract
Many fire-prone forests are experiencing wildfires that burn outside the historical range of variation in extent and severity. These fires impact pollinators and the ecosystem services they provide, but how the effects of fire are mediated by burn severity in different habitats is not well understood. We used generalized linear mixed models in a Bayesian framework to model the abundance of pollinators as a function of burn severity, habitat, and floral resources in post-fire, mid-elevation, conifer forest, and meadow in the Sierra Nevada, California. Although most species-level effects were not significant, we found highly consistent negative impacts of burn severity in meadows where pollinators were most abundant, with only hummingbirds and some butterfly families responding positively to burn severity in meadows. Moderate-severity fire tended to increase the abundance of most pollinator taxa in upland forest habitat, indicating that even in large fires that burn primarily at high- and moderate-severity patches may be associated with improved habitat conditions for pollinator species in upland forest. Nearly all pollinator taxa responded positively to floral richness but not necessarily to floral abundance. Given that much of the Sierra Nevada is predicted to burn at high severity, limiting high-severity effects in meadow and upland habitats may help conserve pollinator communities whereas low- to moderate-severity fire may be needed in both systems.
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Affiliation(s)
- Gina L. Tarbill
- Pacific Southwest Research StationUSDA, Forest ServiceDavisCaliforniaUSA
- Wildlife, Fish, & Conservation BiologyUniversity of California, DavisDavisCaliforniaUSA
| | - Angela M. White
- Pacific Southwest Research StationUSDA, Forest ServiceDavisCaliforniaUSA
| | - Rahel Sollmann
- Wildlife, Fish, & Conservation BiologyUniversity of California, DavisDavisCaliforniaUSA
- Department of Ecological DynamicsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
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4
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Mills TJT, Nelson TM, Pearson LA, Neilan BA. Hive Transplantation Has Minimal Impact on the Core Gut Microbiome of the Australian Stingless Bee, Tetragonula carbonaria. MICROBIAL ECOLOGY 2023; 86:2086-2096. [PMID: 37088849 PMCID: PMC10497653 DOI: 10.1007/s00248-023-02222-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Bacteria residing in the guts of pollinating insects play a key role in nutrient acquisition, digestion, and resistance to pests and diseases. Imbalances in microbial flora in response to environmental change and stress can therefore impact insect health and resilience. This study is aimed at defining the core gut microbiome of the Australian native stingless bee, Tetragonula carbonaria, and exploring the impact of colony transplantation on gut health. The gut microbiomes of nine forager bees from natural (log) and manufactured (box) hives were examined via 16S rRNA gene amplicon sequencing. Some differences were observed at the ASV level between the microbiomes of log and box hive bees. However, a core microbiome, dominated by Lactobacillus spp., unclassified Acetobacteraceae spp., and Bombella spp., was maintained. Further, the inferred functional potential of the microbiomes was consistent across all individuals. This study highlights that although hive transplantation has an impact on the overall diversity of stingless bee gut microbiomes, it is unlikely to have a significant negative impact on the overall health and resilience of the colony.
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Affiliation(s)
- T J T Mills
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - T M Nelson
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - L A Pearson
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - B A Neilan
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia.
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5
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Rittschof CC, Denny AS. The Impacts of Early-Life Experience on Bee Phenotypes and Fitness. Integr Comp Biol 2023; 63:808-824. [PMID: 36881719 DOI: 10.1093/icb/icad009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023] Open
Abstract
Across diverse animal species, early-life experiences have lifelong impacts on a variety of traits. The scope of these impacts, their implications, and the mechanisms that drive these effects are central research foci for a variety of disciplines in biology, from ecology and evolution to molecular biology and neuroscience. Here, we review the role of early life in shaping adult phenotypes and fitness in bees, emphasizing the possibility that bees are ideal species to investigate variation in early-life experience and its consequences at both individual and population levels. Bee early life includes the larval and pupal stages, critical time periods during which factors like food availability, maternal care, and temperature set the phenotypic trajectory for an individual's lifetime. We discuss how some common traits impacted by these experiences, including development rate and adult body size, influence fitness at the individual level, with possible ramifications at the population level. Finally, we review ways in which human alterations to the landscape may impact bee populations through early-life effects. This review highlights aspects of bees' natural history and behavioral ecology that warrant further investigation with the goal of understanding how environmental disturbances threaten these vulnerable species.
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Affiliation(s)
- Clare C Rittschof
- Department of Entomology, University of Kentucky, S-225 Agricultural Science Center North, Lexington, KY 40546, USA
| | - Amanda S Denny
- Department of Entomology, University of Kentucky, S-225 Agricultural Science Center North, Lexington, KY 40546, USA
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6
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Russo L, Ruedenauer F, Gronert A, Van de Vreken I, Vanderplanck M, Michez D, Klein A, Leonhardt S, Stout JC. Fertilizer and herbicide alter nectar and pollen quality with consequences for pollinator floral choices. PeerJ 2023; 11:e15452. [PMID: 37334137 PMCID: PMC10269573 DOI: 10.7717/peerj.15452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/03/2023] [Indexed: 06/20/2023] Open
Abstract
Background Pollinating insects provide economically and ecologically valuable services, but are threatened by a variety of anthropogenic changes. The availability and quality of floral resources may be affected by anthropogenic land use. For example, flower-visiting insects in agroecosystems rely on weeds on field edges for foraging resources, but these weeds are often exposed to agrochemicals that may compromise the quality of their floral resources. Methods We conducted complementary field and greenhouse experiments to evaluate the: (1) effect of low concentrations of agrochemical exposure on nectar and pollen quality and (2) relationship between floral resource quality and insect visitation. We applied the same agrochemcial treatments (low concentrations of fertilizer, low concentrations of herbicide, a combination of both, and a control of just water) to seven plant species in the field and greenhouse. We collected data on floral visitation by insects in the field experiment for two field seasons and collected pollen and nectar from focal plants in the greenhouse to avoid interfering with insect visitation in the field. Results We found pollen amino acid concentrations were lower in plants exposed to low concentrations of herbicide, and pollen fatty acid concentrations were lower in plants exposed to low concentrations of fertilizer, while nectar amino acids were higher in plants exposed to low concentrations of either fertilizer or herbicide. Exposure to low fertilizer concentrations also increased the quantity of pollen and nectar produced per flower. The responses of plants exposed to the experimental treatments in the greenhouse helped explain insect visitation in the field study. The insect visitation rate correlated with nectar amino acids, pollen amino acids, and pollen fatty acids. An interaction between pollen protein and floral display suggested pollen amino acid concentrations drove insect preference among plant species when floral display sizes were large. We show that floral resource quality is sensitive to agrochemical exposure and that flower-visiting insects are sensitive to variation in floral resource quality.
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Affiliation(s)
- Laura Russo
- University of Tennessee, Knoxville, United States of America
- Trinity College Dublin, Dublin, Ireland
| | | | - Angela Gronert
- Chair of Nature Conservation and Landscape Ecology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | | | | | | | - Alexandra Klein
- Chair of Nature Conservation and Landscape Ecology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
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7
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Sladonja B, Tlak Gajger I, Uzelac M, Poljuha D, Garau C, Landeka N, Barták M, Bacaro G. The Impact of Beehive Proximity, Human Activity and Agricultural Intensity on Diptera Diversity in a Mediterranean Mosaic of Agroecosystems, with a Focus on Pest Species. Animals (Basel) 2023; 13:ani13061024. [PMID: 36978565 PMCID: PMC10044344 DOI: 10.3390/ani13061024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Diptera, with their participation in pollination, significantly contribute to the maintenance of plant diversity, and they also have great potential for assessing habitat health and preserving it. A decline in their abundance and diversity has been recorded worldwide as a consequence of biotic, abiotic, and anthropic alterations. In addition to pollinators, these orders include agricultural and forestry pests, which are a threat to both cultivated and wild plants that are very important to the economy. Many pests have escaped from their native areas, and it is important to monitor their spread to implement sustainable means of control. Our study provides baseline information on Diptera and Vespidae diversity in the Mediterranean mosaic of agroecosystems, giving information on the importance of human influence on insect diversity. We carried out an insect inventory in Istria, Croatia, using a set of traps placed in the proximity of beehives. This study was also important in determining the presence of pests and newly introduced species. A total of 94 species from 24 families were recorded—7 important agricultural pests of Diptera and 17 new records for Croatia. The correlation between species diversity and environmental and anthropogenic factors leads to the conclusion that total insect species richness, pest species richness, and the first findings depend on human activities. The number of honeybee colonies negatively correlated with species richness, while anthropic influence positively affected total and pest species richness.
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Affiliation(s)
- Barbara Sladonja
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia
| | - Ivana Tlak Gajger
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia
- Correspondence: ; Tel.: +385-91-2390-041
| | - Mirela Uzelac
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia
| | - Danijela Poljuha
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia
| | - Clara Garau
- Department of Life and Environment Botanical Section, University of Cagliari, Viale S. Ignazio da Laconi 13, 09123 Cagliari, Italy
| | - Nediljko Landeka
- Public Health Institute of the Istrian Region, Nazorova 23, 52100 Pula, Croatia
| | - Miroslav Barták
- Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha 6, Suchdol, Czech Republic
| | - Giovanni Bacaro
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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8
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Abstract
Stingless bees form perennial colonies of honey-making insects. The >600 species of stingless bees, mainly Neotropical, live throughout tropical latitudes. Foragers influence floral biology, plant reproduction, microbe dispersal, and diverse ecosystem functions. As tropical forest residents since the upper Cretaceous, they have had a long evolutionary history without competition from honey bees. Most stingless bees are smaller than any Apis species and recruit nest mates to resources, while their defense strategies exclude stinging behavior but incorporate biting. Stingless bees have diversified ecologically; excel in nesting site selection and mutualisms with plants, arthropods, and microbes; and display opportunism, including co-opting plant defenses. As their biology becomes better known, applications to human endeavors are imposing selective pressures from exploitation and approaches to conservation that entail colony extraction from wildlands. Although some meliponines can adjust to new conditions, their populations shall require tropical diversity for survival and reproduction.
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Affiliation(s)
- David W Roubik
- Smithsonian Tropical Research Institute, Balboa, Republic of Panamá;
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9
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Long-term spatiotemporal patterns in the number of colonies and honey production in Mexico. Sci Rep 2023; 13:1017. [PMID: 36653357 PMCID: PMC9849204 DOI: 10.1038/s41598-022-25469-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/30/2022] [Indexed: 01/19/2023] Open
Abstract
Honey bee decline is currently one of the world's most serious environmental issues, and scientists, governments, and producers have generated interest in understanding its causes and consequences in honey production and food supply. Mexico is one of the world's top honey producers, however, the honey bee population's status has not been documented to date. Based on 32 years of data from beekeeping, we make a country-level assessment of honey bee colony trends in Mexico. We use generalized additive mixed models to measure the associations between the percent change in honey bee hives and the percent change in honey yield per hive in relation to land-use, climate, and socioeconomic conditions. Despite the fact that the average annual yield per hive increased from 1980 to 2012, we detected a significant decline in the percent change in the number of honey bee hives across the time period studied. We also found a relationship between climatic conditions and agricultural land use, with agriculture increases and high temperatures producing a decrease in the percent change in honey yield. We found a relationship between a reduction in the temperature range (the difference between maximum and minimum temperatures) and a decrease in the percent change in the number of hives, while socioeconomic factors related to poverty levels have an impact on the number of hives and honey yields. Although long-term declines in hive numbers are not correlated with poverty levels, socioeconomic factors in states with high and medium poverty levels limit the increase in honey yield per hive. These results provide evidence that land-use changes, unfavorable climatic conditions, political, and socioeconomic factors are partially responsible for the reductions in the percent change in honey bee hives in Mexico.
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10
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Boff S, Keller A, Raizer J, Lupi D. Decreased efficiency of pollen collection due to Sulfoxaflor exposure leads to a reduction in the size of bumble bee workers in late European summer. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.842563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bumble bees (Bombus terrestris) are important pollinators of wild and crop plants. Despite their importance in the process of fruit and seed production on crop sites, their activity may be impaired due to exposure to pesticides. This species has a yearly life cycle and colony success may rely on effective foraging of workers on ruderal plants late in summer when most crops are no longer flowering. In the current study, we investigated the effect of chronic exposure to Sulfoxaflor on aspects of the foraging behavior of bumble bees and whether Sulfoxaflor influences the body size of workers of B. terrestris in a crop landscape. We found that 2 weeks of continuous exposure to Sulfoxaflor influenced workers’ foraging dynamics and collection of resources. However, there was no evidence that the 5 ppb dose of the pesticide impacted the ability of bees to handle flowers with different traits. Workers from colonies exposed to Sulfoxaflor were smaller. The effect on worker size may be explained as a consequence of the reduced pollen income per unit of worker foraging. Thus, if the effects of Sulfoxaflor applied directly to crops had the same effect as that observed on commercial bumble bees after our chronic exposure, it might negatively impact colony success due to the impact on pollen collection and the reduction in the size of workers.
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11
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Wintermantel D, Pereira-Peixoto MH, Warth N, Melcher K, Faller M, Feurer J, Allan MJ, Dean R, Tamburini G, Knauer AC, Schwarz JM, Albrecht M, Klein AM. Flowering resources modulate the sensitivity of bumblebees to a common fungicide. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154450. [PMID: 35276144 DOI: 10.1016/j.scitotenv.2022.154450] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/12/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
Bees are exposed to various stressors, including pesticides and lack of flowering resources. Despite potential interactions between these stressors, the impacts of pesticides on bees are generally assumed to be consistent across bee-attractive crops, and regulatory risk assessments of pesticides neglect interactions with flowering resources. Furthermore, impacts of fungicides on bees are rarely examined in peer-reviewed studies, although these are often the pesticides that bees are most exposed to. In a full-factorial semi-field experiment with 39 large flight cages, we assessed the single and combined impacts of the globally used azoxystrobin-based fungicide Amistar® and three types of flowering resources (Phacelia, buckwheat, and a floral mix) on Bombus terrestris colonies. Although Amistar is classified as bee-safe, Amistar exposure through Phacelia monocultures reduced adult worker body mass and colony growth (including a 55% decline in workers and an 88% decline in males), while the fungicide had no impact on colonies in buckwheat or the floral mix cages. Furthermore, buckwheat monocultures hampered survival and fecundity irrespective of fungicide exposure. This shows that bumblebees require access to complementary flowering species to gain both fitness and fungicide tolerance and that Amistar impacts are flowering resource-dependent. Our findings call for further research on how different flowering plants affect bees and their pesticide tolerance to improve guidelines for regulatory pesticide risk assessments and inform the choice of plants that are cultivated to safeguard pollinators.
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Affiliation(s)
- Dimitry Wintermantel
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany.
| | | | - Nadja Warth
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany
| | - Kristin Melcher
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany
| | - Michael Faller
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany
| | - Joachim Feurer
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany
| | | | - Robin Dean
- Red Beehive Company, Bishops Waltham, United Kingdom
| | - Giovanni Tamburini
- University of Bari, Department of Soil, Plant and Food Sciences (DiSSPA - Entomology), Bari, Italy
| | - Anina C Knauer
- Agroscope, Agroecology and Environment, Zurich, Switzerland
| | | | | | - Alexandra-Maria Klein
- University of Freiburg, Nature Conservation and Landscape Ecology, Freiburg, Germany
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12
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Jones J, Rader R. Pollinator nutrition and its role in merging the dual objectives of pollinator health and optimal crop production. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210170. [PMID: 35491607 PMCID: PMC9058521 DOI: 10.1098/rstb.2021.0170] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Bee and non-bee insect pollinators play an integral role in the quantity and quality of production for many food crops, yet there is growing evidence that nutritional challenges to pollinators in agricultural landscapes are an important factor in the reduction of pollinator populations worldwide. Schemes to enhance crop pollinator health have historically focused on floral resource plantings aimed at increasing pollinator abundance and diversity by providing more foraging opportunities for bees. These efforts have demonstrated that improvements in bee diversity and abundance are achievable; however, goals of increasing crop pollination outcomes via these interventions are not consistently met. To support pollinator health and crop pollination outcomes in tandem, habitat enhancements must be tailored to meet the life-history needs of specific crop pollinators, including non-bees. This will require greater understanding of the nutritional demands of these taxa together with the supply of floral and non-floral food resources and how these interact in cropping environments. Understanding the mechanisms underlying crop pollination and pollinator health in unison across a range of taxa is clearly a win–win for industry and conservation, yet achievement of these goals will require new knowledge and novel, targeted methods. This article is part of the theme issue ‘Natural processes influencing pollinator health: from chemistry to landscapes’.
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Affiliation(s)
- Jeremy Jones
- School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
| | - Romina Rader
- School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
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13
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Weidenmüller A, Meltzer A, Neupert S, Schwarz A, Kleineidam C. Glyphosate impairs collective thermoregulation in bumblebees. Science 2022; 376:1122-1126. [PMID: 35653462 DOI: 10.1126/science.abf7482] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Insects are facing a multitude of anthropogenic stressors, and the recent decline in their biodiversity is threatening ecosystems and economies across the globe. We investigated the impact of glyphosate, the most commonly used herbicide worldwide, on bumblebees. Bumblebee colonies maintain their brood at high temperatures via active thermogenesis, a prerequisite for colony growth and reproduction. Using a within-colony comparative approach to examine the effects of long-term glyphosate exposure on both individual and collective thermoregulation, we found that whereas effects are weak at the level of the individual, the collective ability to maintain the necessary high brood temperatures is decreased by more than 25% during periods of resource limitation. For pollinators in our heavily stressed ecosystems, glyphosate exposure carries hidden costs that have so far been largely overlooked.
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Affiliation(s)
- Anja Weidenmüller
- Centre for the Advanced Study of Collective Behavior, Konstanz, Germany
- University of Konstanz, Konstanz, Germany
| | - Andrea Meltzer
- University of Konstanz, Konstanz, Germany
- Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Stefanie Neupert
- University of Konstanz, Konstanz, Germany
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Alica Schwarz
- Centre for the Advanced Study of Collective Behavior, Konstanz, Germany
- University of Konstanz, Konstanz, Germany
| | - Christoph Kleineidam
- Centre for the Advanced Study of Collective Behavior, Konstanz, Germany
- University of Konstanz, Konstanz, Germany
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14
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Peters B, Keller A, Leonhardt SD. Diets maintained in a changing world: Does land‐use intensification alter wild bee communities by selecting for flexible generalists? Ecol Evol 2022; 12:e8919. [PMID: 35600696 PMCID: PMC9108308 DOI: 10.1002/ece3.8919] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 04/07/2022] [Accepted: 04/19/2022] [Indexed: 11/08/2022] Open
Affiliation(s)
- Birte Peters
- Department for Animal Ecology and Tropical Biology University of Würzburg Biocenter Würzburg Germany
- Department of Bioinformatics University of Würzburg Biocenter Würzburg Germany
- Center for Computational and Theoretical Biology University of Würzburg Würzburg Germany
| | - Alexander Keller
- Cellular and Organismic Networks Faculty of Biology Ludwig‐Maximilians‐Universität Munich Planegg‐Martinsried Germany
| | - Sara Diana Leonhardt
- Department for Animal Ecology and Tropical Biology University of Würzburg Biocenter Würzburg Germany
- Department of Life Science Systems Technical University of Munich Freising Germany
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15
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Wagner B, Egerer M. Application of UAV remote sensing and machine learning to model and map land use in urban gardens. JOURNAL OF URBAN ECOLOGY 2022. [DOI: 10.1093/jue/juac008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Urban gardens are an integral part of urban agricultural systems, contributing to ecosystem services, biodiversity and human wellbeing. These systems occur at fine scales, can be highly complex and therefore offer the opportunity to test mechanisms of ecological patterns and processes. The capacity to confidently characterize urban gardens and their land uses is still lacking, while it could provide the basis for assessing ecosystem service provision. Land classifications from remote sensing platforms are common at the landscape scale, but imagery often lacks the resolution required to map differences in land use of fine-scale systems such as urban gardens. Here, we present a workflow to model and map land use in urban gardens using imagery from an unoccupied aerial vehicle (UAV) and machine learning. Due to high resolutions (<5 cm) from image acquisition at low altitudes, UAV remote sensing is better suited to characterize urban land use. We mapped six common land uses in 10 urban community gardens, exhibiting distinct spatial arrangements. Our models had good predictive performance, reaching 80% overall prediction accuracy in independent validation and up to 95% when assessing model performance per cover class. Extracting spatial metrics from these land use classifications, we found that at the garden and plot scale, plant species richness can be estimated by the total area and patchiness of crops. Land use classifications like these can offer an accessible tool to assess complex urban habitats and justify the importance of urban agriculture as a service-providing system, contributing to the sustainability and livability of cities.
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Affiliation(s)
- Benjamin Wagner
- Faculty of Science, School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, VIC 3121, Australia
| | - Monika Egerer
- Department of Life Science Systems, School of Life Sciences, Technical University of Munich, Hans Carl-von-Carlowitz-Platz 2, Freising 85354, Germany
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16
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Carneiro de Melo Moura C, Setyaningsih CA, Li K, Merk MS, Schulze S, Raffiudin R, Grass I, Behling H, Tscharntke T, Westphal C, Gailing O. Biomonitoring via DNA metabarcoding and light microscopy of bee pollen in rainforest transformation landscapes of Sumatra. BMC Ecol Evol 2022; 22:51. [PMID: 35473550 PMCID: PMC9040256 DOI: 10.1186/s12862-022-02004-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intense conversion of tropical forests into agricultural systems contributes to habitat loss and the decline of ecosystem functions. Plant-pollinator interactions buffer the process of forest fragmentation, ensuring gene flow across isolated patches of forests by pollen transfer. In this study, we identified the composition of pollen grains stored in pot-pollen of stingless bees, Tetragonula laeviceps, via dual-locus DNA metabarcoding (ITS2 and rbcL) and light microscopy, and compared the taxonomic coverage of pollen sampled in distinct land-use systems categorized in four levels of management intensity (forest, shrub, rubber, and oil palm) for landscape characterization. RESULTS Plant composition differed significantly between DNA metabarcoding and light microscopy. The overlap in the plant families identified via light microscopy and DNA metabarcoding techniques was low and ranged from 22.6 to 27.8%. Taxonomic assignments showed a dominance of pollen from bee-pollinated plants, including oil-bearing crops such as the introduced species Elaeis guineensis (Arecaceae) as one of the predominant taxa in the pollen samples across all four land-use types. Native plant families Moraceae, Euphorbiaceae, and Cannabaceae appeared in high proportion in the analyzed pollen material. One-way ANOVA (p > 0.05), PERMANOVA (R² values range from 0.14003 to 0.17684, for all tests p-value > 0.5), and NMDS (stress values ranging from 0.1515 to 0.1859) indicated a lack of differentiation between the species composition and diversity of pollen type in the four distinct land-use types, supporting the influx of pollen from adjacent areas. CONCLUSIONS Stingless bees collected pollen from a variety of agricultural crops, weeds, and wild plants. Plant composition detected at the family level from the pollen samples likely reflects the plant composition at the landscape level rather than the plot level. In our study, the plant diversity in pollen from colonies installed in land-use systems with distinct levels of forest transformation was highly homogeneous, reflecting a large influx of pollen transported by stingless bees through distinct land-use types. Dual-locus approach applied in metabarcoding studies and visual pollen identification showed great differences in the detection of the plant community, therefore a combination of both methods is recommended for performing biodiversity assessments via pollen identification.
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Affiliation(s)
| | - Christina A Setyaningsih
- Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Kevin Li
- Agroecology, Department of Crop Sciences, University of Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Miryam Sarah Merk
- Statistics and Econometrics, University of Göttingen, Göttingen, Germany
| | - Sonja Schulze
- Agroecology, Department of Crop Sciences, University of Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Rika Raffiudin
- Department of Biology, IPB University ID, Bogor, West Java, 16880, Indonesia
| | - Ingo Grass
- Department of Ecology of Tropical Agricultural Systems, University of Hohenheim, 70599, Stuttgart, Germany
| | - Hermann Behling
- Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37073, Göttingen, Germany
| | - Teja Tscharntke
- Agroecology, Department of Crop Sciences, University of Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Catrin Westphal
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Oliver Gailing
- Department of Forest Genetics and Forest Tree Breeding, University of Göttingen, 37077, Göttingen, Germany. .,Centre of Biodiversity and Sustainable Land Use, University of Göttingen, 37077, Göttingen, Germany.
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17
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Abstract
The identification of floral visitation by pollinators provides an opportunity to improve our understanding of the fine-scale ecological interactions between plants and pollinators, contributing to biodiversity conservation and promoting ecosystem health. In this review, we outline the various methods which can be used to identify floral visitation, including plant-focused and insect-focused methods. We reviewed the literature covering the ways in which DNA metabarcoding has been used to answer ecological questions relating to plant use by pollinators and discuss the findings of this research. We present detailed methodological considerations for each step of the metabarcoding workflow, from sampling through to amplification, and finally bioinformatic analysis. Detailed guidance is provided to researchers for utilisation of these techniques, emphasising the importance of standardisation of methods and improving the reliability of results. Future opportunities and directions of using molecular methods to analyse plant–pollinator interactions are then discussed.
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18
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Trueman SJ, Kämper W, Nichols J, Ogbourne SM, Hawkes D, Peters T, Hosseini Bai S, Wallace HM. Pollen limitation and xenia effects in a cultivated mass-flowering tree, Macadamia integrifolia (Proteaceae). ANNALS OF BOTANY 2022; 129:135-146. [PMID: 34473241 PMCID: PMC8796667 DOI: 10.1093/aob/mcab112] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND AIMS Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9200 million tons of annual global food production. METHODS We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200 000-400 000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. KEY RESULTS Macadamia trees were pollen-limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97, 109 and 92 %, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84 and 100 % of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality (i.e. xenia). CONCLUSIONS This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31-0.59 tons ha-1, which equates currently to higher farm-gate income of approximately $US3720-$US7080 ha-1. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.
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Affiliation(s)
- Stephen J Trueman
- Centre for Planetary Health and Food Security, School of Environment and
Science, Griffith University, Nathan, QLD 4111,
Australia
| | - Wiebke Kämper
- Centre for Planetary Health and Food Security, School of Environment and
Science, Griffith University, Nathan, QLD 4111,
Australia
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-University
Bochum, 44780 Bochum, Germany
| | - Joel Nichols
- Centre for Planetary Health and Food Security, School of Environment and
Science, Griffith University, Nathan, QLD 4111,
Australia
| | - Steven M Ogbourne
- GeneCology Research Centre, University of the Sunshine Coast,
Maroochydore DC, QLD 4558, Australia
- School of Science, Technology & Engineering, University of the Sunshine
Coast, Maroochydore DC, QLD 4558, Australia
| | - David Hawkes
- Australian Genome Research Facility, Gehrmann Laboratories, University of
Queensland, Brisbane, QLD 4072, Australia
| | - Trent Peters
- Australian Genome Research Facility, Gehrmann Laboratories, University of
Queensland, Brisbane, QLD 4072, Australia
| | - Shahla Hosseini Bai
- Centre for Planetary Health and Food Security, School of Environment and
Science, Griffith University, Nathan, QLD 4111,
Australia
| | - Helen M Wallace
- Centre for Planetary Health and Food Security, School of Environment and
Science, Griffith University, Nathan, QLD 4111,
Australia
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19
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Seitz B, Buchholz S, Kowarik I, Herrmann J, Neuerburg L, Wendler J, Winker L, Egerer M. Land sharing between cultivated and wild plants: urban gardens as hotspots for plant diversity in cities. Urban Ecosyst 2022. [DOI: 10.1007/s11252-021-01198-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
AbstractPlant communities in urban gardens consist of cultivated species, including ornamentals and food crops, and wild growing species. Yet it remains unclear what significance urban gardens have for the plant diversity in cities and how the diversity of cultivated and wild plants depends on the level of urbanization. We sampled plants growing within 18 community gardens in Berlin, Germany to investigate the species diversity of cultivated and wild plants. We tested species diversity in relation to local and landscape-scale imperviousness as a measure of urbanity, and we investigated the relationship between cultivated and wild plant species within the gardens. We found that numbers of wild and cultivated plant species in gardens are high – especially of wild plant species – independent of landscape-scale imperviousness. This suggests that all community gardens, regardless of their urban contexts, can be important habitats for plant diversity along with their role in urban food provision. However, the number of all species was negatively predicted by local garden scale imperviousness, suggesting an opportunity to reduce imperviousness and create more habitats for plants at the garden scale. Finally, we found a positive relationship between the number of cultivated and wild growing species, which emphasizes that community gardens present a unique urban ecosystem where land sharing between cultivated and wild flora can transpire. As the urban agriculture movement is flourishing worldwide with gardens continuously and spontaneously arising and dissipating due to urban densification, such botanical investigations can support the argument that gardens are places for the reconciliation of plant conservation and food production.
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20
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Parreño MA, Alaux C, Brunet JL, Buydens L, Filipiak M, Henry M, Keller A, Klein AM, Kuhlmann M, Leroy C, Meeus I, Palmer-Young E, Piot N, Requier F, Ruedenauer F, Smagghe G, Stevenson PC, Leonhardt SD. Critical links between biodiversity and health in wild bee conservation. Trends Ecol Evol 2021; 37:309-321. [PMID: 34955328 DOI: 10.1016/j.tree.2021.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 11/29/2022]
Abstract
Wild bee populations are declining due to human activities, such as land use change, which strongly affect the composition and diversity of available plants and food sources. The chemical composition of food (i.e., nutrition) in turn determines the health, resilience, and fitness of bees. For pollinators, however, the term 'health' is recent and is subject to debate, as is the interaction between nutrition and wild bee health. We define bee health as a multidimensional concept in a novel integrative framework linking bee biological traits (physiology, stoichiometry, and disease) and environmental factors (floral diversity and nutritional landscapes). Linking information on tolerated nutritional niches and health in different bee species will allow us to better predict their distribution and responses to environmental change, and thus support wild pollinator conservation.
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Affiliation(s)
- M A Parreño
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany.
| | - C Alaux
- INRAE, Abeilles et Environnement, Avignon, France
| | - J-L Brunet
- INRAE, Abeilles et Environnement, Avignon, France
| | - L Buydens
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - M Filipiak
- Faculty of Biology, Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - M Henry
- INRAE, Abeilles et Environnement, Avignon, France
| | - A Keller
- Center for Computational and Theoretical Biology, and Department of Bioinformatics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - A-M Klein
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Freiburg, Germany
| | - M Kuhlmann
- Zoological Museum of Kiel University, Kiel, Germany
| | - C Leroy
- INRAE, Abeilles et Environnement, Avignon, France
| | - I Meeus
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - E Palmer-Young
- US Department of Agriculture (USDA) Agricultural Research Service Bee Research Laboratory, Beltsville, MD, USA
| | - N Piot
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - F Requier
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement, et Écologie, 91198 Gif-sur-Yvette, France
| | - F Ruedenauer
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany
| | - G Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - P C Stevenson
- Royal Botanic Gardens, Kew, Surrey TW9 3AE, UK; University of Greenwich, London, UK
| | - S D Leonhardt
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany.
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21
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Quaresma A, Brodschneider R, Gratzer K, Gray A, Keller A, Kilpinen O, Rufino J, van der Steen J, Vejsnæs F, Pinto MA. Preservation methods of honey bee-collected pollen are not a source of bias in ITS2 metabarcoding. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:785. [PMID: 34755261 DOI: 10.1007/s10661-021-09563-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Pollen metabarcoding is emerging as a powerful tool for ecological research and offers unprecedented scale in citizen science projects for environmental monitoring via honey bees. Biases in metabarcoding can be introduced at any stage of sample processing and preservation is at the forefront of the pipeline. While in metabarcoding studies pollen has been preserved at - 20 °C (FRZ), this is not the best method for citizen scientists. Herein, we compared this method with ethanol (EtOH), silica gel (SG) and room temperature (RT) for preservation of pollen collected from hives in Austria and Denmark. After ~ 4 months of storage, DNAs were extracted with a food kit, and their quality and concentration measured. Most DNA extracts exhibited 260/280 absorbance ratios close to the optimal 1.8, with RT samples from Austria performing slightly worse than FRZ and SG samples (P < 0.027). Statistical differences were also detected for DNA concentration, with EtOH samples producing lower yields than RT and FRZ samples in both countries and SG in Austria (P < 0.042). Yet, qualitative and quantitative assessments of floral composition obtained using high-throughput sequencing with the ITS2 barcode gave non-significant effects of preservation methods on richness, relative abundance and Shannon diversity, in both countries. While freezing and ethanol are commonly employed for archiving tissue for molecular applications, desiccation is cheaper and easier to use regarding both storage and transportation. Since SG is less dependent on ambient humidity and less prone to contamination than RT, we recommend SG for preserving pollen for metabarcoding. SG is straightforward for laymen to use and hence robust for widespread application in citizen science studies.
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Affiliation(s)
- Andreia Quaresma
- Centro de Investigação de Montanha, Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253, Bragança, Portugal
| | - Robert Brodschneider
- Institute of Biology, University of Graz, Universitätsplatz 2, 8010, Graz, Austria
| | - Kristina Gratzer
- Institute of Biology, University of Graz, Universitätsplatz 2, 8010, Graz, Austria
| | - Alison Gray
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - Alexander Keller
- Center for Computational and Theoretical Biology, Hubland Nord, Würzburg, Germany
- Department of Bioinformatics, University of Würzburg, Am Hubland, BiocenterWürzburg, Germany
| | | | - José Rufino
- Research Centre in Digitalization and Intelligent Robotics (CeDRI), Instituto Politécnico de Bragança, Bragança, Portugal
| | | | | | - M Alice Pinto
- Centro de Investigação de Montanha, Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253, Bragança, Portugal.
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22
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CSI Pollen: Diversity of Honey Bee Collected Pollen Studied by Citizen Scientists. INSECTS 2021; 12:insects12110987. [PMID: 34821788 PMCID: PMC8625907 DOI: 10.3390/insects12110987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 10/27/2021] [Indexed: 11/17/2022]
Abstract
A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way. Altogether, 750 beekeepers from 28 different regions from 24 countries participated in the two-year study and collected and analyzed almost 18,000 pollen samples. Pollen samples contained approximately six different colors in total throughout the sampling period, of which four colors were abundant. We ran generalized linear mixed models to test for possible effects of diverse factors such as collection, i.e., whether a minimum amount of pollen was collected or not, and habitat type on the number of colors found in pollen samples. To identify habitat effects on pollen diversity, beekeepers' descriptions of the surrounding landscape and CORINE land cover classes were investigated in two different models, which both showed that both the total number and the rare number of colors in pollen samples were positively affected by 'urban' habitats or 'artificial surfaces', respectively. This citizen science study underlines the importance of the habitat for pollen diversity for bees and suggests higher diversity in urban areas.
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23
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van der Kooi CJ, Vallejo-Marín M, Leonhardt SD. Mutualisms and (A)symmetry in Plant-Pollinator Interactions. Curr Biol 2021; 31:R91-R99. [PMID: 33497641 DOI: 10.1016/j.cub.2020.11.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The majority of flowering plants relies on animal pollinators for sexual reproduction and many animal pollinators rely on floral resources. However, interests of plants and pollinators are often not the same, resulting in an asymmetric relationship that ranges from mutualistic to parasitic interactions. Our understanding of the processes that underlie this asymmetry remains fragmentary. In this Review, we bring together evidence from evolutionary biology, plant chemistry, biomechanics, sensory ecology and behaviour to illustrate that the degree of symmetry often depends on the perspective taken. We also highlight variation in (a)symmetry within and between plant and pollinator species as well as between geographic locations. Through taking different perspectives from the plant and pollinator sides we provide new ground for studies on the maintenance and evolution of animal pollination and on the (a)symmetry in plant-pollinator interactions.
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Affiliation(s)
- Casper J van der Kooi
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
| | | | - Sara D Leonhardt
- Department of Ecology and Ecosystem Management, Technical University of Munich, Freising, Germany
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24
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Jachuła J, Denisow B, Wrzesień M. Habitat heterogeneity helps to mitigate pollinator nectar sugar deficit and discontinuity in an agricultural landscape. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 782:146909. [PMID: 33848857 DOI: 10.1016/j.scitotenv.2021.146909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/28/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
The scarcity of floral resources and their seasonal discontinuity are considered as major factors for pollinator decline in intensified agricultural landscapes worldwide. The consequences are detrimental for the stability of the environment and ecosystems. Here, we quantified the production of nectar sugars in plant species occurring in man-made, non-cropped areas (non-forest woody vegetation, road verges, railway embankments, field margins, fallow areas) of an agricultural landscape in SE Poland. We also assessed changes in the availability of sugar resources both in space (habitat and landscape scales) and in time (throughout the flowering season), and checked to what extent the sugar demands of honeybees and bumblebees are met at the landscape scale. At landscape-level, 37.6% of the available sugar resources are produced in man-made, non-cropped habitats, while 32.6% and 15.0% of sugars derive from winter rape crops and forest vegetation, respectively. Nectar sugar supplies vary greatly between man-made, non-cropped habitat types/sub-types. These areas are characterized by a high richness of nectar-producing species. However, a predominant role in total sugar resources is ascribable to a few species. Strong fluctuations in nectar resources are recorded throughout the flowering season. March and June are periods with food shortages. Abundant nectar sugars are generally found in April-May, mainly due to the mass flowering of nectar-yielding species in the forests, meadows/pastures and orchards/rapeseed crops. Heterogeneity of man-made, non-cropped habitats is essential to support the supply of July-October nectar sugars for honeybees and bumblebees. Reduced flowering in man-made non-cropped habitats can generate serious food deficiencies, as from summer towards the end of the flowering season >90% of sugars are provided by the flora of these areas. Therefore, highly nectar-yielding plant species that flower during periods of expected food shortages should be a priority for conservation and restoration programs.
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Affiliation(s)
- Jacek Jachuła
- Department of Botany and Plant Physiology, Subdepartment of Plant Biology, University of Life Sciences, 15 Akademicka St., 20-950 Lublin, Poland
| | - Bożena Denisow
- Department of Botany and Plant Physiology, Subdepartment of Plant Biology, University of Life Sciences, 15 Akademicka St., 20-950 Lublin, Poland.
| | - Małgorzata Wrzesień
- Department of Botany, Mycology, and Ecology, Maria Curie-Sklodowska University, 19 Akademicka St., 20-033 Lublin, Poland.
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25
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Agroecological Strategies to Safeguard Insect Pollinators in Biodiversity Hotspots: Chile as a Case Study. SUSTAINABILITY 2021. [DOI: 10.3390/su13126728] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Industrial agriculture (IA) has been recognized among the main drivers of biodiversity loss, climate change, and native pollinator decline. Here we summarize the known negative effects of IA on pollinator biodiversity and illustrate these problems by considering the case of Chile, a “world biodiversity hotspot” (WBH) where food exports account for a considerable share of the economy in this country. Most of Chile’s WBH area is currently being replaced by IA at a fast pace, threatening local biodiversity. We present an agroecological strategy for sustainable food production and pollinator conservation in food-producing WBHs. In this we recognize native pollinators as internal inputs that cannot be replaced by IA technological packages and support the development of agroecological and biodiversity restorative practices to protect biodiversity. We suggest four fundamental pillars for food production change based on: (1) sharing the land, restoring and protecting; (2) ecological intensification; (3) localized knowledge, research, and technological development; and (4) territorial planning and implementation of socio-agroecological policies. This approach does not need modification of native pollination services that sustain the world with food and basic subsistence goods, but a paradigm change where the interdependency of nature and human wellbeing must be recognized for ensuring the world’s food security and sovereignty.
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Hung KLJ, Sandoval SS, Ascher JS, Holway DA. Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot. INSECTS 2021; 12:insects12020135. [PMID: 33562453 PMCID: PMC7914906 DOI: 10.3390/insects12020135] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/28/2021] [Accepted: 02/02/2021] [Indexed: 01/27/2023]
Abstract
Simple Summary Global climate change is causing more frequent and severe droughts, which can have serious impacts on our environment. To examine how a severe drought in 2014 impacted wild bees in scrub habitats of San Diego, California, we compared bee samples collected before and after the drought. We also investigated whether habitat loss and fragmentation worsened the impacts of drought on wild bees by comparing samples collected from large natural reserves to those from small fragments of scrub habitat embedded in urban areas. Samples collected after the drought contained fewer bee species and fewer individual bees of most species, indicating that bee populations suffered losses during the drought. However, after-drought samples contained large numbers of Dialictus sweat bees, indicating that some bee species benefitted from environmental conditions present during the drought. The impact of drought on the composition of bee samples was three fold higher than the impact of habitat fragmentation, and habitat fragmentation did not appear to have exacerbated the impacts of drought. Our findings highlight the importance of studying how impacts of climate change compare with impacts of habitat loss and other threats to biodiversity conservation. Abstract Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragmented habitat patches versus unfragmented natural reserves. Bee richness and diversity were higher in assemblages surveyed before the drought compared to those surveyed after the drought. However, bees belonging to the Lasioglossum subgenus Dialictus increased in abundance after the drought, driving increased representation by small-bodied, primitively eusocial, and generalist bees in post-drought assemblages. Conversely, among non-Dialictus bees, post-drought years were associated with decreased abundance and reduced representation by eusocial species. Drought effects were consistently greater in reserves, which supported more bee species, than in fragments, suggesting that fragmentation either had redundant impacts with drought, or ameliorated effects of drought by enhancing bees’ access to floral resources in irrigated urban environments. Shifts in assemblage composition associated with drought were three times greater compared to those associated with habitat fragmentation, highlighting the importance of understanding the impacts of large-scale climatic events relative to those associated with land use change.
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Affiliation(s)
- Keng-Lou James Hung
- Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA; (S.S.S.); (D.A.H.)
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M5S 3B2, Canada
- Correspondence:
| | - Sara S. Sandoval
- Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA; (S.S.S.); (D.A.H.)
| | - John S. Ascher
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore;
| | - David A. Holway
- Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA; (S.S.S.); (D.A.H.)
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27
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Local and Landscape Compositions Influence Stingless Bee Communities and Pollination Networks in Tropical Mixed Fruit Orchards, Thailand. DIVERSITY 2020. [DOI: 10.3390/d12120482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stingless bees are vital pollinators for both wild and crop plants, yet their communities have been affected and altered by anthropogenic land-use change. Additionally, few studies have directly addressed the consequences of land-use change for meliponines, and knowledge on how their communities change across gradients in surrounding landscape cover remains scarce. Here, we examine both how local and landscape-level compositions as well as forest proximity affect both meliponine species richness and abundance together with pollination networks across 30 mixed fruit orchards in Southern Thailand. The results reveal that most landscape-level factors significantly influenced both stingless bee richness and abundance. Surrounding forest cover has a strong positive direct effect on both factors, while agricultural and urbanized cover generally reduced both bee abundance and diversity. In the local habitat, there is a significant interaction between orchard size and floral richness with stingless bee richness. We also found that pollinator specialization in pollination networks decreased when the distance to the forest patch increased. Both local and landscape factors thus influenced meliponine assemblages, particularly the forest patches surrounding an orchard, which potentially act as a key reservoir for stingless bees and other pollinator taxa. Preservation of forest patches can protect the permanent nesting and foraging habitat of various pollinator taxa, resulting in high visitation for crop and wild plants.
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Hall MA, Brettell LE, Liu H, Nacko S, Spooner-Hart R, Riegler M, Cook JM. Temporal changes in the microbiome of stingless bee foragers following colony relocation. FEMS Microbiol Ecol 2020; 97:5998223. [DOI: 10.1093/femsec/fiaa236] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 11/18/2020] [Indexed: 12/26/2022] Open
Abstract
ABSTRACT
Maintaining beneficial interactions with microbial symbionts is vital for animal health. Yet, for social insects, the stability of microbial associations within and between cohorts is largely unknown. We investigated temporal changes in the microbiomes of nine stingless bee (Tetragonula carbonaria) colonies at seven timepoints across a 10-month period when moved between two climatically and florally different sites. Bacterial 16S rRNA gene and fungal ITS amplicon sequencing confirmed that microbiomes varied considerably between colonies initially at site one. However, following relocation, considerable changes occurred in bacterial community composition within each colony, and the microbiome composition became more similar across colonies. Notably, Snodgrassella disappeared and Zymobacter appeared as relatively abundant taxa. Remarkably, bacterial communities within colonies continued to shift over time but remained similar across colonies, becoming dominated by Acinetobacter six months after returning to the original site. Our results indicate that the stingless bee microbiome can undergo major changes in response to the environment, and that these changes can be long-lasting. Such legacy effects have not been reported for corbiculate bees. Further understanding the microbial ecology of stingless bees will aid future management of colonies used in agricultural production.
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Affiliation(s)
- Mark A Hall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Laura E Brettell
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Hongwei Liu
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Scott Nacko
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Robert Spooner-Hart
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Markus Riegler
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - James M Cook
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
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29
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Leonhardt SD, Lihoreau M, Spaethe J. Mechanisms of Nutritional Resource Exploitation by Insects. INSECTS 2020; 11:insects11090570. [PMID: 32854218 PMCID: PMC7564569 DOI: 10.3390/insects11090570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022]
Abstract
Insects have evolved an extraordinary range of nutritional adaptations to exploit other animals, plants, bacteria, fungi and soils as resources in terrestrial and aquatic environments. This special issue provides some new insights into the mechanisms underlying these adaptations. Contributions comprise lab and field studies investigating the chemical, physiological, cognitive and behavioral mechanisms that enable resource exploitation and nutrient intake regulation in insects. The collection of papers highlights the need for more studies on the comparative sensory ecology, underlying nutritional quality assessment, cue perception and decision making to fully understand how insects adjust resource selection and exploitation in response to environmental heterogeneity and variability.
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Affiliation(s)
- Sara D. Leonhardt
- Plant-Insect-Interactions Group, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
- Correspondence:
| | - Mathieu Lihoreau
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI); CNRS, University Paul Sabatier - Toulouse III, 31062 Toulouse, France;
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Biozentrum, Am Hubland, 97074 Würzburg, Germany;
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30
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Significance of Apoidea as Main Pollinators. Ecological and Economic Impact and Implications for Human Nutrition. DIVERSITY 2020. [DOI: 10.3390/d12070280] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Wild and managed bees provide pollination services to crops and wild plants, as well as a variety of other services beneficial to humans. Honey bees are the most economically valuable pollinator worldwide. It has been calculated that 9.5% of the total economic value of agricultural production comes from insect pollination, thus amounting to just under USD 200 billion globally. More than 100 important crops depend on pollination by honey bees. The latter pollinate not only a wide number of commercial crops but also many wild plants, some of which are threatened by extinction and constitute a valuable genetic resource. Moreover, as pollinators, honey bees play a significant role in every aspect of the ecosystem by facilitating the growth of trees, flowers, and other plants that serve as food and shelter for many large and small creatures. In this paper, we describe how the reduction in honey bee populations affects various economic sectors, as well as human health.
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31
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Boff S, Raizer J, Lupi D. Environmental Display Can Buffer the Effect of Pesticides on Solitary Bees. INSECTS 2020; 11:E417. [PMID: 32635667 PMCID: PMC7412123 DOI: 10.3390/insects11070417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/25/2020] [Accepted: 07/03/2020] [Indexed: 02/07/2023]
Abstract
Environmental quality (e.g., diversity of resource availability, nesting sites, environmental display) plays an important role in an animal's life. While homogeneous environments can restrict organisms from developing activities such as food seeking (behavioral impairment), more complex environments allow animals to perform activities with learning and behavioral perfecting outcomes. Pesticides are known to affect the learning and foraging behaviors of bees; however, little is known about the counterbalance displayed by the environment. Herein, we conducted two experiments that simulated distinct environmental displays, in which the effects of a fungicide (IndarTM 5EW-febunconazole) on solitary bee foraging activities were tested. We found that the fungicide only impaired the activities of bees in one of the studied environments. The difference in visitation rates and flower exploitation of bees between the two different environmental displays led to changes in metrics of bee-flower networks across environments. Linkage density, a metric associated with pollination efficiency that is known to be impacted by different environments, differed across environments. Our results showed that ecological interaction network metrics can differ regarding the different environmental displays. This study indicates that environmental complexity helps balance the negative effects of pesticides on solitary bees and highlights the potential use of solitary bees as model organisms for experimental simulations of environmental change.
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Affiliation(s)
- Samuel Boff
- University of Milan, Department of Food Environmental and Nutritional Sciences, 20133 Milan, Italy;
| | - Josué Raizer
- Universidade Federal da Grande Dourados, Faculdade de Ciências Biológicas e Ambientais, Dourados 79840-970, Brazil;
| | - Daniela Lupi
- University of Milan, Department of Food Environmental and Nutritional Sciences, 20133 Milan, Italy;
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32
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Ramalho MDO, Martins C, Morini MSC, Bueno OC. What Can the Bacterial Community of Atta sexdens (Linnaeus, 1758) Tell Us about the Habitats in Which This Ant Species Evolves? INSECTS 2020; 11:E332. [PMID: 32481532 PMCID: PMC7349130 DOI: 10.3390/insects11060332] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 12/22/2022]
Abstract
Studies of bacterial communities can reveal the evolutionary significance of symbiotic interactions between hosts and their associated bacteria, as well as identify environmental factors that may influence host biology. Atta sexdens is an ant species native to Brazil that can act as an agricultural pest due to its intense behavior of cutting plants. Despite being extensively studied, certain aspects of the general biology of this species remain unclear, such as the evolutionary implications of the symbiotic relationships it forms with bacteria. Using high-throughput amplicon sequencing of 16S rRNA genes, we compared for the first time the bacterial community of A. sexdens (whole ant workers) populations according to the habitat (natural versus agricultural) and geographical location. Our results revealed that the bacterial community associated with A. sexdens is mainly influenced by the geographical location, and secondarily by the differences in habitat. Also, the bacterial community associated with citrus differed significantly from the other communities due to the presence of Tsukamurella. In conclusion, our study suggests that environmental shifts may influence the bacterial diversity found in A. sexdens.
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Affiliation(s)
- Manuela de Oliveira Ramalho
- Centro de Estudos de Insetos Sociais—CEIS, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro 13506-900, SP, Brazil;
- Department of Entomology, Cornell University, 129 Garden Ave, Ithaca, NY 14850, USA
| | - Cintia Martins
- Campus Ministro Reis Velloso, Universidade Federal do Piauí, Av. São Sebastião, 2819, Parnaíba, Piauí 64202-020, Brazil;
| | - Maria Santina Castro Morini
- Núcleo de Ciências Ambientais, Universidade de Mogi das Cruzes, Av. Dr. Cândido Xavier de Almeida e Souza, 200, Centro Cívico, Mogi das Cruzes 08780-911, SP, Brazil;
| | - Odair Correa Bueno
- Centro de Estudos de Insetos Sociais—CEIS, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro 13506-900, SP, Brazil;
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33
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Thomson DM, Page ML. The importance of competition between insect pollinators in the Anthropocene. CURRENT OPINION IN INSECT SCIENCE 2020; 38:55-62. [PMID: 32145696 DOI: 10.1016/j.cois.2019.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/11/2019] [Accepted: 11/19/2019] [Indexed: 05/08/2023]
Abstract
Resource competition likely plays an important role in some insect pollinator declines and in shaping effects of environmental change on pollination services. Past research supports that competition for floral resources affects bee foragers, but mostly with observational evidence and rarely linking foraging with population change. An increasing number of studies ask whether resources limit pollinator populations, using field measurements of reproductive success, time series and models. Findings generally support positive effects of floral resources, but also highlight the potential importance of nest site availability and parasitism. In parallel, recent experiments strengthen evidence that competition reduces access to floral resources. Developing common currencies for quantifying floral resources and integrating analyses of multiple limiting factors will further strengthen our understanding of competitive interactions and their effects in the Anthropocene.
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Affiliation(s)
- Diane M Thomson
- W.M. Keck Science Department, The Claremont Colleges, 925 N. Mills Avenue, Claremont, CA 91711, United States.
| | - Maureen L Page
- Department of Entomology and Nematology, University of California, Davis, CA 95616, United States
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34
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Feldhaar H, Otti O. Pollutants and Their Interaction with Diseases of Social Hymenoptera. INSECTS 2020; 11:insects11030153. [PMID: 32121502 PMCID: PMC7142568 DOI: 10.3390/insects11030153] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 02/18/2020] [Accepted: 02/24/2020] [Indexed: 12/07/2022]
Abstract
Many insect species, including social insects, are currently declining in abundance and diversity. Pollutants such as pesticides, heavy metals, or airborne fine particulate matter from agricultural and industrial sources are among the factors driving this decline. While these pollutants can have direct detrimental effects, they can also result in negative interactive effects when social insects are simultaneously exposed to multiple stressors. For example, sublethal effects of pollutants can increase the disease susceptibility of social insects, and thereby jeopardize their survival. Here we review how pesticides, heavy metals, or airborne fine particulate matter interact with social insect physiology and especially the insects’ immune system. We then give an overview of the current knowledge of the interactive effects of these pollutants with pathogens or parasites. While the effects of pesticide exposure on social insects and their interactions with pathogens have been relatively well studied, the effects of other pollutants, such as heavy metals in soil or fine particulate matter from combustion, vehicular transport, agriculture, and coal mining are still largely unknown. We therefore provide an overview of urgently needed knowledge in order to mitigate the decline of social insects.
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35
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Trinkl M, Kaluza BF, Wallace H, Heard TA, Keller A, Leonhardt SD. Floral Species Richness Correlates with Changes in the Nutritional Quality of Larval Diets in a Stingless Bee. INSECTS 2020; 11:E125. [PMID: 32075297 PMCID: PMC7073955 DOI: 10.3390/insects11020125] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/25/2020] [Accepted: 02/03/2020] [Indexed: 11/16/2022]
Abstract
Bees need food of appropriate nutritional quality to maintain their metabolic functions. They largely obtain all required nutrients from floral resources, i.e., pollen and nectar. However, the diversity, composition and nutritional quality of floral resources varies with the surrounding environment and can be strongly altered in human-impacted habitats. We investigated whether differences in plant species richness as found in the surrounding environment correlated with variation in the floral diversity and nutritional quality of larval provisions (i.e., mixtures of pollen, nectar and salivary secretions) composed by the mass-provisioning stingless bee Tetragonula carbonaria (Apidae: Meliponini). We found that the floral diversity of larval provisions increased with increasing plant species richness. The sucrose and fat (total fatty acid) content and the proportion and concentration of the omega-6 fatty acid linoleic acid decreased, whereas the proportion of the omega-3 fatty acid linolenic acid increased with increasing plant species richness. Protein (total amino acid) content and amino acid composition did not change. The protein to fat (P:F) ratio, known to affect bee foraging, increased on average by more than 40% from plantations to forests and gardens, while the omega-6:3 ratio, known to negatively affect cognitive performance, decreased with increasing plant species richness. Our results suggest that plant species richness may support T. carbonaria colonies by providing not only a continuous resource supply (as shown in a previous study), but also floral resources of high nutritional quality.
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Affiliation(s)
- Moritz Trinkl
- Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany;
| | - Benjamin F. Kaluza
- Department of Public Technology and Innovation Planning, Fraunhofer Institute for Technological Trend Analysis INT, 53879 Euskirchen, Germany
| | - Helen Wallace
- Environmental Futures Research Institute, Griffith University, Nathan Campus, QLD 4111, Australia;
| | - Tim A. Heard
- CSIRO Ecosystem Sciences, Brisbane, QLD 4001, Australia;
| | - Alexander Keller
- Center for Computational and Theoretical Biology, University of Würzburg, 97074 Würzburg, Germany;
| | - Sara D. Leonhardt
- Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany;
- Department of Ecology and Ecosystem Management, Technical University of Munich, 85354 Freising, Germany
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36
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Population Growth and Insecticide Residues of Honey Bees in Tropical Agricultural Landscapes. DIVERSITY-BASEL 2019. [DOI: 10.3390/d12010001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Global decline of pollinators, especially bees, has been documented in many countries. Several causes such as land-use change and agricultural intensification are reported to be the main drivers of the decline. The objective of this study was to investigate the effect of land use on honey bee and stingless bee populations. Research was conducted in Bogor and Malang to compare between two different geographical areas. Managed bees such as honey bees (Apis cerana and A. mellifera) and stingless bees (Tetragonula laeviceps) were investigated to examine the effect of agricultural intensification. Field experiments were conducted by placing beehives in selected habitats (i.e., beekeeper gardens, forests areas, and agriculture areas). Population growth and neonicotinoid residue analysis of bees in different hive locations were measured to study the effect of habitat type. Population growth of bees represents the forager abundance and colony weight. Based on the analysis, we found that habitat type affected forager abundance and colony weight of honey bees (p < 0.05), although the patterns were different between species, region, as well as season. Forests could support the stingless bee colony better than agriculture and home garden habitats. Insecticide (neonicotinoid) was barely recorded in both honey bees and stingless bees.
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37
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The effects of urbanization on bee communities depends on floral resource availability and bee functional traits. PLoS One 2019; 14:e0225852. [PMID: 31790482 PMCID: PMC6886752 DOI: 10.1371/journal.pone.0225852] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 11/13/2019] [Indexed: 11/24/2022] Open
Abstract
Wild bees are important pollinators in many ecosystems threatened by anthropogenic disturbance. Urban development can reduce and degrade natural habitat for bees and other pollinators. However, some researchers suggest that cities could also provide refuge for bees, given that agricultural intensification may pose a greater risk. In this study, we surveyed bee communities at 15 farms and gardens across an urban-rural gradient in southeastern Michigan, USA to evaluate the effect of urbanization on bees. We examined how floral resources, bee functional traits, temperature, farm size, and the spatial scale of analysis influence bee response to urbanization. We found that urbanization positively affected bee diversity and evenness but had no effect on total abundance or species richness. Additionally, urbanization altered bee community composition via differential effects on bee species and functional groups. More urbanized sites supported a greater number of exotic, above-ground nesting, and solitary bees, but fewer eusocial bees. Blooming plant species richness positively influenced bee species diversity and richness. Furthermore, the amount of available floral resources was positively associated with exotic and eusocial bee abundances. Across sites, nearly 70% of floral resources were provided by exotic plants, most of which are characterized as weedy but not invasive. Our study demonstrates that urbanization can benefit some bee species and negatively impact others. Notably, Bombus and Lasioglossum (Dialictus), were two important pollinator groups negatively affected by urbanization. Our study supports the idea that urban environments can provide valuable habitat for diverse bee communities, but demonstrates that some bees are vulnerable to urbanization. Finally, while our results indicate that increasing the abundance and richness of floral resources could partially compensate for negative effects of urbanization on bees, the effectiveness of such measures may be limited by other factors, such as urban warming.
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38
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Brodschneider R, Gratzer K, Kalcher-Sommersguter E, Heigl H, Auer W, Moosbeckhofer R, Crailsheim K. A citizen science supported study on seasonal diversity and monoflorality of pollen collected by honey bees in Austria. Sci Rep 2019; 9:16633. [PMID: 31719621 PMCID: PMC6851371 DOI: 10.1038/s41598-019-53016-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/26/2019] [Indexed: 11/29/2022] Open
Abstract
Austrian beekeepers participated in the “C.S.I. Pollen” study as citizen scientists and collected pollen from honey bee colonies in hive mounted traps every three weeks from April to September in 2014 and 2015 to uncover the seasonal availability of pollen sources for bees. 1622 pollen samples were collected and analysed using palynological light microscopy to the lowest taxonomic level possible. For 2014 and 2015 combined, 239 pollen types from more than 85 families were detected. ‘Various unknown’ species, Taraxacum-form and Plantago spp. were the pollen types collected by the majority of colonies (occurrence), whereas the most pollen grains collected were from Trifolium repens-form, Plantago spp. and Salix spp. (abundance). In spring, trees were found to be the most abundant pollen source, whereas in summer herbs dominated. On average, a colony collected pollen from 16.8 ± 4.7 (2014) and 15.0 ± 4.4 (2015) pollen types per sampling. Those numbers, however, vary between sampling dates and indicate a seasonal pattern. This is also supported by Simpson’s diversity index, which was on median 0.668. In both years, 50.0% of analysed pollen samples were partially (>50%) and 4.2% were highly monofloral (i.e. containing >90% of one pollen type). Prevalence of monofloral pollen samples peaked at the beginning and the end of the season, when pollen diversity was the lowest.
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Affiliation(s)
- Robert Brodschneider
- University of Graz, Institute of Biology, Universitätsplatz 2, 8010, Graz, Austria.
| | - Kristina Gratzer
- University of Graz, Institute of Biology, Universitätsplatz 2, 8010, Graz, Austria
| | | | - Helmut Heigl
- Austrian Agency for Health and Food Safety, Ltd., Institute for Seed and Propagating Material, Plant Protection Service and Apiculture, Department for Apiculture and Bee Protection, Vienna, Austria
| | - Waltraud Auer
- Austrian Agency for Health and Food Safety, Ltd., Institute for Seed and Propagating Material, Plant Protection Service and Apiculture, Department for Apiculture and Bee Protection, Vienna, Austria
| | - Rudolf Moosbeckhofer
- Austrian Agency for Health and Food Safety, Ltd., Institute for Seed and Propagating Material, Plant Protection Service and Apiculture, Department for Apiculture and Bee Protection, Vienna, Austria
| | - Karl Crailsheim
- University of Graz, Institute of Biology, Universitätsplatz 2, 8010, Graz, Austria
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39
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The influence of garden flowers on pollinator visits to forest flowers: comparison of bumblebee habitat use between urban and natural areas. Urban Ecosyst 2019. [DOI: 10.1007/s11252-019-00891-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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40
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Belsky J, Joshi NK. Impact of Biotic and Abiotic Stressors on Managed and Feral Bees. INSECTS 2019; 10:E233. [PMID: 31374933 PMCID: PMC6723792 DOI: 10.3390/insects10080233] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 07/17/2019] [Accepted: 07/25/2019] [Indexed: 01/14/2023]
Abstract
Large-scale declines in bee abundance and species richness over the last decade have sounded an alarm, given the crucial pollination services that bees provide. Population dips have specifically been noted for both managed and feral bee species. The simultaneous increased cultivation of bee-dependent agricultural crops has given rise to additional concern. As a result, there has been a surge in scientific research investigating the potential stressors impacting bees. A group of environmental and anthropogenic stressors negatively impacting bees has been isolated. Habitat destruction has diminished the availability of bee floral resources and nest habitats, while massive monoculture plantings have limited bee access to a variety of pollens and nectars. The rapid spread and increased resistance buildup of various bee parasites, pathogens, and pests to current control methods are implicated in deteriorating bee health. Similarly, many pesticides that are widely applied on agricultural crops and within beehives are toxic to bees. The global distribution of honey bee colonies (including queens with attendant bees) and bumble bee colonies from crop to crop for pollination events has been linked with increased pathogen stress and increased competition with native bee species for limited resources. Climatic alterations have disrupted synchronous bee emergence with flower blooming and reduced the availability of diverse floral resources, leading to bee physiological adaptations. Interactions amongst multiple stressors have created colossal maladies hitting bees at one time, and in some cases delivering additive impacts. Initiatives including the development of wild flower plantings and assessment of pesticide toxicity to bees have been undertaken in efforts to ameliorate current bee declines. In this review, recent findings regarding the impact of these stressors on bees and strategies for mitigating them are discussed.
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Affiliation(s)
- Joseph Belsky
- Department of Entomology, University of Arkansas, 319 Agricultural Building, Fayetteville, AR 72701, USA
| | - Neelendra K Joshi
- Department of Entomology, University of Arkansas, 319 Agricultural Building, Fayetteville, AR 72701, USA.
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41
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Filipiak M. Key pollen host plants provide balanced diets for wild bee larvae: A lesson for planting flower strips and hedgerows. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13383] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Michał Filipiak
- Institute of Environmental SciencesJagiellonian University Kraków Poland
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