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Gray LK, Hulsey M, Siviter H. A novel insecticide impairs bumblebee memory and sucrose responsiveness across high and low nutrition. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231798. [PMID: 38721128 PMCID: PMC11076119 DOI: 10.1098/rsos.231798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/01/2024] [Accepted: 03/18/2024] [Indexed: 07/31/2024]
Abstract
Wild bees are important pollinators of crops and wildflowers but are exposed to a myriad of different anthropogenic stressors, such as pesticides and poor nutrition, as a consequence of intensive agriculture. These stressors do not act in isolation, but interact, and may exacerbate one another. Here, we assessed whether a field-realistic concentration of flupyradifurone, a novel pesticide that has been labelled as 'bee safe' by regulators, influenced bumblebee sucrose responsiveness and long-term memory. In a fully crossed experimental design, we exposed individual bumblebees (Bombus impatiens) to flupyradifurone at high (50% (w/w)) or low (15% (w/w)) sucrose concentrations, replicating diets that are either carbohydrate rich or poor, respectively. We found that flupyradifurone impaired sucrose responsiveness and long-term memory at both sucrose concentrations, indicating that better nutrition did not buffer the negative impact of flupyradifurone. We found no individual impact of sugar deficiency on bee behaviour and no significant interactions between pesticide exposure and poor nutrition. Our results add to a growing body of evidence demonstrating that flupyradifurone has significant negative impacts on pollinators, indicating that this pesticide is not 'bee safe'. This suggests that agrochemical risk assessments are not protecting pollinators from the unintended consequences of pesticide use.
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Affiliation(s)
- Lily K. Gray
- Department of Integrative Biology, University of Texas at Austin, Austin, TX78712, USA
| | - Marcus Hulsey
- Department of Integrative Biology, University of Texas at Austin, Austin, TX78712, USA
- University of Oklahoma, Norman, OK73019, USA
| | - Harry Siviter
- Department of Integrative Biology, University of Texas at Austin, Austin, TX78712, USA
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, UK
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2
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Williams NM, Buderi A, Rowe L, Ward K. Wildflower plantings enhance nesting opportunities for soil-nesting bees. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2935. [PMID: 38071699 DOI: 10.1002/eap.2935] [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: 06/08/2023] [Accepted: 09/15/2023] [Indexed: 01/27/2024]
Abstract
Ongoing declines of bees and other pollinators are driven in part by the loss of critical floral resources and nesting substrates. Most conservation/restoration efforts for bees aim to enhance floral abundance and continuity but often assume the same actions will bolster nesting opportunities. Recent research suggests that habitat plantings may not always provide both forage and nesting resources. We evaluated wildflower plantings designed to augment floral resources to determine their ability to enhance nesting by soil-nesting bees over 3 study years in Northern California agricultural landscapes. We established wildflower plantings along borders of annual row crops and paired each with an unplanted control border. We used soil emergence traps to assess nest densities and species richness of soil-nesting bees from spring through late summer at paired field borders planted with wildflowers or maintained conventionally as bare or sparsely vegetated areas, as is typical for the region. We also quantified soil-surface characteristics and flower resources among borders. Wildflower plantings significantly increased nest densities and the richness of bee species using them. Such benefits occurred within the first year of planting and persisted up to 4 years post establishment. The composition of nesting bee communities also differed between wildflower and unenhanced borders. Wildflower plantings differed from controls in multiple characteristics of the soil surface, including vegetation cover, surface microtopography and hardness. Surprisingly, only vegetation cover significantly affected nest densities and species richness. Wildflower plantings are a widespread habitat action with the potential to support wild bees. The demonstrated benefit wildflower plantings had for increasing the nesting of soil-nesting bees greatly augments their relevance for the conservation of wild bee communities in agricultural and other landscapes. Identifying soil-surface characteristics that are important for nesting provides critical information to guide the implementation and management of habitats for bees.
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Affiliation(s)
- Neal M Williams
- Department of Entomology and Nematology, University of California, Davis, Davis, California, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, USA
| | - Andrew Buderi
- Department of Entomology and Nematology, University of California, Davis, Davis, California, USA
| | - Logan Rowe
- Department of Entomology and Nematology, University of California, Davis, Davis, California, USA
| | - Kimiora Ward
- Department of Entomology and Nematology, University of California, Davis, Davis, California, USA
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3
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Fischer N, Costa CP, Hur M, Kirkwood JS, Woodard SH. Impacts of neonicotinoid insecticides on bumble bee energy metabolism are revealed under nectar starvation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169388. [PMID: 38104805 DOI: 10.1016/j.scitotenv.2023.169388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
Bumble bees are an important group of insects that provide essential pollination services as a consequence of their foraging behaviors. These pollination services are driven, in part, by energetic exchanges between flowering plants and individual bees. Thus, it is important to examine bumble bee energy metabolism and explore how it might be influenced by external stressors contributing to declines in global pollinator populations. Two stressors that are commonly encountered by bees are insecticides, such as the neonicotinoids, and nutritional stress, resulting from deficits in pollen and nectar availability. Our study uses a metabolomic approach to examine the effects of neonicotinoid insecticide exposure on bumble bee metabolism, both alone and in combination with nutritional stress. We hypothesized that exposure to imidacloprid disrupts bumble bee energy metabolism, leading to changes in key metabolites involved in central carbon metabolism. We tested this by exposing Bombus impatiens workers to imidacloprid according to one of three exposure paradigms designed to explore how chronic versus more acute (early or late) imidacloprid exposure influences energy metabolite levels, then also subjecting them to artificial nectar starvation. The strongest effects of imidacloprid were observed when bees also experienced nectar starvation, suggesting a combinatorial effect of neonicotinoids and nutritional stress on bumble bee energy metabolism. Overall, this study provides important insights into the mechanisms underlying the impact of neonicotinoid insecticides on pollinators, and underscores the need for further investigation into the complex interactions between environmental stressors and energy metabolism.
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Affiliation(s)
- Natalie Fischer
- Department of Entomology, University of California, Riverside, Riverside, CA, USA.
| | - Claudinéia P Costa
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| | - Manhoi Hur
- IIGB Metabolomics Core Facility, University of California, Riverside, Riverside, CA, USA
| | - Jay S Kirkwood
- IIGB Metabolomics Core Facility, University of California, Riverside, Riverside, CA, USA
| | - S Hollis Woodard
- Department of Entomology, University of California, Riverside, Riverside, CA, USA.
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4
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Bretzlaff T, Kerr JT, Darveau CA. Handling heatwaves: balancing thermoregulation, foraging and bumblebee colony success. CONSERVATION PHYSIOLOGY 2024; 12:coae006. [PMID: 38332907 PMCID: PMC10853005 DOI: 10.1093/conphys/coae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/08/2023] [Accepted: 01/02/2024] [Indexed: 02/10/2024]
Abstract
Climate changes pose risks for bumblebee populations, which have declined relative to the growing frequency and severity of warmer temperature extremes. Bumblebees might mitigate the effects of such extreme weather through colonial behaviours. In particular, fanning behaviour to dissipate heat is an important mechanism that could reduce exposure of thermally sensitive offspring to detrimental nest temperatures (Tn). The allocation of workers towards fanning over prolonged periods could impact foraging activity that is essential for colony-sustaining resource gathering. Colony maintenance and growth could suffer as a result of nutritional and high ambient temperature (Ta) thermal stress. It remains uncertain whether a compromise occurs between thermoregulation and foraging under chronic, sublethal heat events and how colony success is impacted as a result. This study held colonies of Bombus impatiens at constant high Ta (25°C, 30°C or 35°C) for 2 weeks while quantifying the percentage of foragers, fanning incidence, nest temperature (Tn) and other metrics of colony success such as the percentage of adult emergence and offspring production. We found that foraging and adult emergence were not significantly affected by Ta, but that thermoregulation was unsuccessful at maintaining Tn despite increased fanning at 35°C. Furthermore, 35°C resulted in workers abandoning the colony and fewer offspring being produced. Our findings imply that heatwave events that exceed 30°C can negatively impact colony success through failed thermoregulation and reduced workforce production.
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Affiliation(s)
- Tiffany Bretzlaff
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada K1N 6N5
| | - Jeremy T Kerr
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada K1N 6N5
| | - Charles-A Darveau
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada K1N 6N5
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5
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Vaudo AD, Dyer LA, Leonard AS. Pollen nutrition structures bee and plant community interactions. Proc Natl Acad Sci U S A 2024; 121:e2317228120. [PMID: 38190523 PMCID: PMC10801918 DOI: 10.1073/pnas.2317228120] [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: 10/09/2023] [Accepted: 11/19/2023] [Indexed: 01/10/2024] Open
Abstract
As bees' main source of protein and lipids, pollen is critical for their development, reproduction, and health. Plant species vary considerably in the macronutrient content of their pollen, and research in bee model systems has established that this variation both modulates performance and guides floral choice. Yet, how variation in pollen chemistry shapes interactions between plants and bees in natural communities is an open question, essential for both understanding the nutritional dynamics of plant-pollinator mutualisms and informing their conservation. To fill this gap, we asked how pollen nutrition (relative protein and lipid content) sampled from 109 co-flowering plant species structured visitation patterns observed among 75 subgenera of pollen-collecting bees in the Great Basin/Eastern Sierra region (USA). We found that the degree of similarity in co-flowering plant species' pollen nutrition predicted similarity among their visitor communities, even after accounting for floral morphology and phylogeny. Consideration of pollen nutrition also shed light on the structure of this interaction network: Bee subgenera and plant genera were arranged into distinct, interconnected groups, delineated by differences in pollen macronutrient values, revealing potential nutritional niches. Importantly, variation in pollen nutrition alone (high in protein, high in lipid, or balanced) did not predict the diversity of bee visitors, indicating that plant species offering complementary pollen nutrition may be equally valuable in supporting bee diversity. Nutritional diversity should thus be a key consideration when selecting plants for habitat restoration, and a nutritionally explicit perspective is needed when considering reward systems involved in the community ecology of pollination.
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Affiliation(s)
- Anthony D. Vaudo
- Department of Biology, University of Nevada, Reno, NV89557
- Rocky Mountain Research Station, United States Department of Agriculture Forest Service, Moscow, ID83843
| | - Lee A. Dyer
- Department of Biology, University of Nevada, Reno, NV89557
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6
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Pioltelli E, Guzzetti L, Larbi MO, Celano R, Piccinelli AL, Galimberti A, Biella P, Labra M. Land use influences the nutrient concentration and composition of pollen and nectar rewards of wildflowers in human-dominated landscapes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168130. [PMID: 37907100 DOI: 10.1016/j.scitotenv.2023.168130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/02/2023]
Abstract
Plant biodiversity is crucial to satisfy the trophic needs of pollinators, mainly through nectar and pollen rewards. However, a few studies have been directed to ascertain the intraspecific variation of chemical features and the nutritional value of nectar and pollen floral rewards in relation to the alteration of landscapes due to human activities. In this study, by using an existing scenario of land use gradients as an open air laboratory, we tested the variation in pollen and nectar nutrient profiles along gradients of urbanization and agriculture intensity, by focusing on sugar, aminoacids of nectar and phytochemicals of pollen from local wild plants. We also highlighted bioactive compounds from plants primary and secondary metabolism due to their importance for insect wellbeing and pollinator health. We surveyed 7 different meadow species foraged by pollinators and common in the main land uses studied. The results indicated that significant variations of nutritional components occur in relation to different land uses, and specifically that the agricultural intensification decreases the sugars and increases the antioxidant content of flower rewards, while the urbanization is positively associated with the total flavonoid content in pollen. These effects are more evident in some species than in others, such as Lotus corniculatus L. (Fabaceae) and Malva sylvestris L. (Malvaceae), as shown by the untargeted metabolomic investigation. This study is crucial for understanding the nutritional landscape quality for pollinators in association to different land uses and sets a base for landscape management and planning of pollinator-friendly strategies by improving the quality of plant rewards to provide benefits to pollinator health in various environmental contexts.
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Affiliation(s)
- Emiliano Pioltelli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Lorenzo Guzzetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Malika Ouled Larbi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Rita Celano
- NBFC, National Biodiversity Future Center, Palermo, 90133, Italy; Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084, Salerno, Italy
| | - Anna Lisa Piccinelli
- NBFC, National Biodiversity Future Center, Palermo, 90133, Italy; Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084, Salerno, Italy
| | - Andrea Galimberti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Paolo Biella
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy.
| | - Massimo Labra
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
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7
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Feuerborn C, Quinlan G, Shippee R, Strausser TL, Terranova T, Grozinger CM, Hines HM. Variance in heat tolerance in bumble bees correlates with species geographic range and is associated with several environmental and biological factors. Ecol Evol 2023; 13:e10730. [PMID: 38034342 PMCID: PMC10682878 DOI: 10.1002/ece3.10730] [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: 08/24/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
Globally, insects have been impacted by climate change, with bumble bees in particular showing range shifts and declining species diversity with global warming. This suggests heat tolerance is a likely factor limiting the distribution and success of these bees. Studies have shown high intraspecific variance in bumble bee thermal tolerance, suggesting biological and environmental factors may be impacting heat resilience. Understanding these factors is important for assessing vulnerability and finding environmental solutions to mitigate effects of climate change. In this study, we assess whether geographic range variation in bumble bees in the eastern United States is associated with heat tolerance and further dissect which other biological and environmental factors explain variation in heat sensitivity in these bees. We examine heat tolerance by caste, sex, and rearing condition (wild/lab) across six eastern US bumble bee species, and assess the role of age, reproductive status, body size, and interactive effects of humidity and temperature on thermal tolerance in Bombus impatiens. We found marked differences in heat tolerance by species that correlate with each species' latitudinal range, habitat, and climatic niche, and we found significant variation in thermal sensitivity by caste and sex. Queens had considerably lower heat tolerance than workers and males, with greater tolerance when queens would first be leaving their natal nest, and lower tolerance after ovary activation. Wild bees tended to have higher heat tolerance than lab reared bees, and body size was associated with heat tolerance only in wild-caught foragers. Humidity showed a strong interaction with heat effects, pointing to the need to regulate relative humidity in thermal assays and consider its role in nature. Altogether, we found most tested biological conditions impact thermal tolerance and highlight the stages of these bees that will be most sensitive to future climate change.
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Affiliation(s)
- Cody Feuerborn
- Department of BiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Gabriela Quinlan
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life SciencesPennsylvania State UniversityUniversity Park, State CollegePennsylvaniaUSA
| | - Rachael Shippee
- Department of BiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Tori L. Strausser
- Department of BiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Department of BiologyUtah State UniversityLoganUtahUSA
| | - Tatiana Terranova
- Department of BiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Christina M. Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life SciencesPennsylvania State UniversityUniversity Park, State CollegePennsylvaniaUSA
| | - Heather M. Hines
- Department of BiologyPennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life SciencesPennsylvania State UniversityUniversity Park, State CollegePennsylvaniaUSA
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8
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White SA, Dillon ME. Climate warming and bumble bee declines: the need to consider sub-lethal heat, carry-over effects, and colony compensation. Front Physiol 2023; 14:1251235. [PMID: 38028807 PMCID: PMC10644220 DOI: 10.3389/fphys.2023.1251235] [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: 07/01/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Global declines in abundance and diversity of insects are now well-documented and increasingly concerning given the critical and diverse roles insects play in all ecosystems. Habitat loss, invasive species, and anthropogenic chemicals are all clearly detrimental to insect populations, but mounting evidence implicates climate change as a key driver of insect declines globally. Warming temperatures combined with increased variability may expose organisms to extreme heat that exceeds tolerance, potentially driving local extirpations. In this context, heat tolerance limits (e.g., critical thermal maximum, CTmax) have been measured for many invertebrates and are often closely linked to climate regions where animals are found. However, temperatures well below CTmax may also have pronounced effects on insects, but have been relatively less studied. Additionally, many insects with out-sized ecological and economic footprints are colonial (e.g., ants, social bees, termites) such that effects of heat on individuals may propagate through or be compensated by the colony. For colonial organisms, measuring direct effects on individuals may therefore reveal little about population-level impacts of changing climates. Here, we use bumble bees (genus Bombus) as a case study to highlight how a limited understanding of heat effects below CTmax and of colonial impacts and responses both likely hinder our ability to explain past and predict future climate change impacts. Insights from bumble bees suggest that, for diverse invertebrates, predicting climate change impacts will require a more nuanced understanding of the effects of heat exposure and additional studies of carry-over effects and compensatory responses by colonies.
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Affiliation(s)
- Sabrina A. White
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, United States
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9
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Page ML, Williams NM. Evidence of exploitative competition between honey bees and native bees in two California landscapes. J Anim Ecol 2023; 92:1802-1814. [PMID: 37386764 DOI: 10.1111/1365-2656.13973] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 05/29/2023] [Indexed: 07/01/2023]
Abstract
Human-mediated species introductions provide real-time experiments in how communities respond to interspecific competition. For example, managed honey bees Apis mellifera (L.) have been widely introduced outside their native range and may compete with native bees for pollen and nectar. Indeed, multiple studies suggest that honey bees and native bees overlap in their use of floral resources. However, for resource overlap to negatively impact resource collection by native bees, resource availability must also decline, and few studies investigate impacts of honey bee competition on native bee floral visits and floral resource availability simultaneously. In this study, we investigate impacts of increasing honey bee abundance on native bee visitation patterns, pollen diets, and nectar and pollen resource availability in two Californian landscapes: wildflower plantings in the Central Valley and montane meadows in the Sierra. We collected data on bee visits to flowers, pollen and nectar availability, and pollen carried on bee bodies across multiple sites in the Sierra and Central Valley. We then constructed plant-pollinator visitation networks to assess how increasing honey bee abundance impacted perceived apparent competition (PAC), a measure of niche overlap, and pollinator specialization (d'). We also compared PAC values against null expectations to address whether observed changes in niche overlap were greater or less than what we would expect given the relative abundances of interacting partners. We find clear evidence of exploitative competition in both ecosystems based on the following results: (1) honey bee competition increased niche overlap between honey bees and native bees, (2) increased honey bee abundance led to decreased pollen and nectar availability in flowers, and (3) native bee communities responded to competition by shifting their floral visits, with some becoming more specialized and others becoming more generalized depending on the ecosystem and bee taxon considered. Although native bees can adapt to honey bee competition by shifting their floral visits, the coexistence of honey bees and native bees is tenuous and will depend on floral resource availability. Preserving and augmenting floral resources is therefore essential in mitigating negative impacts of honey bee competition. In two California ecosystems, honey bee competition decreases pollen and nectar resource availability in flowers and alters native bee diets with potential implications for bee conservation and wildlands management.
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Affiliation(s)
- Maureen L Page
- Department of Entomology and Nematology, University of California, Davis, California, USA
- Department of Entomology, Cornell University, Ithaca, New York, USA
| | - Neal M Williams
- Department of Entomology and Nematology, University of California, Davis, California, USA
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10
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Martinez A, Calhoun AC, Sadd BM. Investigating the influence of diet diversity on infection outcomes in a bumble bee ( Bombus impatiens) and microsporidian ( Nosema bombi) host-pathogen system. FRONTIERS IN INSECT SCIENCE 2023; 3:1207058. [PMID: 38469464 PMCID: PMC10926413 DOI: 10.3389/finsc.2023.1207058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/01/2023] [Indexed: 03/13/2024]
Abstract
Diet can have an array of both direct and indirect effects on an organism's health and fitness, which can influence the outcomes of host-pathogen interactions. Land use changes, which could impact diet quantity and quality, have imposed foraging stress on important natural and agricultural pollinators. Diet related stress could exacerbate existing negative impacts of pathogen infection. Accounting for most of its nutritional intake in terms of protein and many micronutrients, pollen can influence bee health through changes in immunity, infection, and various aspects of individual and colony fitness. We investigate how adult pollen consumption, pollen type, and pollen diversity influence bumble bee Bombus impatiens survival and infection outcomes for a microsporidian pathogen Nosema (Vairimorpha) bombi. Experimental pathogen exposures of larvae occurred in microcolonies and newly emerged adult workers were given one of three predominantly monofloral, polyfloral, or no pollen diets. Workers were assessed for size, pollen consumption, infection 8-days following adult-eclosion, survival, and the presence of extracellular microsporidian spores at death. Pollen diet treatment, specifically absence of pollen, and infection independently reduced survival, but we saw no effects of pollen, pollen type, or pollen diet diversity on infection outcomes. The latter suggests infection outcomes were likely already set, prior to differential diets. Although infection outcomes were not altered by pollen diet in our study, it highlights both pathogen infection and pollen availability as important for bumble bee health, and these factors may interact at different stages of bumble bee development, at the colony level, or under different dietary regimes.
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Affiliation(s)
| | | | - Ben M. Sadd
- School of Biological Sciences, Illinois State University, Normal, IL, United States
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11
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Malfi RL, McFrederick QS, Lozano G, Irwin RE, Adler LS. Sunflower plantings reduce a common gut pathogen and increase queen production in common eastern bumblebee colonies. Proc Biol Sci 2023; 290:20230055. [PMID: 37015273 PMCID: PMC10072944 DOI: 10.1098/rspb.2023.0055] [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: 05/13/2022] [Accepted: 03/10/2023] [Indexed: 04/06/2023] Open
Abstract
Community diversity can reduce the prevalence and spread of disease, but certain species may play a disproportionate role in diluting or amplifying pathogens. Flowers act as both sources of nutrition and sites of pathogen transmission, but the effects of specific plant species in shaping bee disease dynamics are not well understood. We evaluated whether plantings of sunflower (Helianthus annuus), whose pollen reduces infection by some pathogens when fed to bees in captivity, lowered pathogen levels and increased reproduction in free-foraging bumblebee colonies (Bombus impatiens). Sunflower abundance reduced the prevalence of a common gut pathogen, Crithidia bombi, and reduced infection intensity, with an order of magnitude lower infection intensity at high sunflower sites compared with sites with little to no sunflower. Sunflower abundance was also positively associated with greater queen production in colonies. Sunflower did not affect prevalence of other detected pathogens. This work demonstrates that a single plant species can drive disease dynamics in foraging B. impatiens, and that sunflower plantings can be used as a tool for mitigating a prevalent pathogen while also increasing reproduction of an agriculturally important bee species.
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Affiliation(s)
- Rosemary L. Malfi
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | | | - Giselle Lozano
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Rebecca E. Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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12
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Treanore ED, Ramos-Medero AV, Garcia J, Amsalem E. The Effect of Pollen Diet Composition and Quantity on Diapause Survival and Performance in an Annual Pollinator ( Bombus Impatiens). Integr Org Biol 2023; 5:obad014. [PMID: 37139245 PMCID: PMC10150274 DOI: 10.1093/iob/obad014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 05/05/2023] Open
Abstract
Most pollination services are provided by annual bees that go through a winter diapause, during which they are exposed to extreme temperatures, pathogens, and starvation. The ability of bees to successfully face these stressors during diapause and subsequently initiate a nest depends on their overall nutritional state and an adequate preparatory diet. Here, we used queens of the common eastern bumble bee, Bombus impatiens, to examine how pollen diets varying in their protein to lipid ratio and total nutrient amounts affected queen performance during and after diapause. We compared diapause survival and reproductive performance post-diapause across different diets and found that queen survival was highest when pollen had a nutritional ratio of approximately 5:1 (protein to lipid). This diet is significantly enriched in proteins compared to the pollen fed to bumble bees in the lab (1:1) or commonly available in agricultural landscapes. Altering the quantity of macronutrients within this ratio did not improve survival or performance. Our results emphasize the importance of adequate nutrition for diapause performance in bees with annual life cycles and the importance of providing annual bees with floral provisioning based on their individual nutritional targets.
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Affiliation(s)
| | - A V Ramos-Medero
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - J Garcia
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - E Amsalem
- Department of Entomology, Center for Chemical Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
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13
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Vaudo AD, Erickson E, Patch HM, Grozinger CM, Mu J. Impacts of soil nutrition on floral traits, pollinator attraction, and fitness in cucumbers (Cucumis sativus L.). Sci Rep 2022; 12:21802. [PMID: 36526706 PMCID: PMC9758155 DOI: 10.1038/s41598-022-26164-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Annual plants allocate soil nutrients to floral display and pollinator rewards to ensure pollination success in a single season. Nitrogen and phosphorus are critical soil nutrients whose levels are altered by intensive land use that may affect plants' fitness via pollinator attractiveness through floral display and rewards. In a controlled greenhouse study, we studied in cucumbers (Cucumis sativus) how changes in soil nitrogen and phosphorus influence floral traits, including nectar and pollen reward composition. We evaluated how these traits affect bumble bee (Bombus impatiens, an important cucumber pollinator) visitation and ultimately fruit yield. While increasing nitrogen and phosphorus increased growth and floral display, excess nitrogen created an asymptotic or negative effect, which was mitigated by increasing phosphorus. Male floral traits exhibited higher plasticity in responses to changes in soil nutrients than female flowers. At 4:1 nitrogen:phosphorus ratios, male flowers presented increased nectar volume and pollen number resulting in increased bumble bee visitation. Interestingly, other pollinator rewards remained consistent across all soil treatments: male and female nectar sugar composition, female nectar volume, and pollen protein and lipid concentrations. Therefore, although cucumber pollination success was buffered in conditions of nutrient stress, highly skewed nitrogen:phosphorus soil ratios reduced plant fitness via reduced numbers of flowers and reward quantity, pollinator attraction, and ultimately yield.
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Affiliation(s)
- Anthony D Vaudo
- Department of Biology, University of Nevada Reno, Reno, NV, 89557, USA.
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Emily Erickson
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Harland M Patch
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Junpeng Mu
- Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University, Mianyang, 621000, China
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14
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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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15
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Costa CP, Leza M, Duennes MA, Fisher K, Vollaro A, Hur M, Kirkwood JS, Woodard SH. Pollen diet mediates how pesticide exposure impacts brain gene expression in nest-founding bumble bee queens. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 833:155216. [PMID: 35421476 DOI: 10.1016/j.scitotenv.2022.155216] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
A primary goal in biology is to understand the effects of multiple, interacting environmental stressors on organisms. Wild and domesticated bees are exposed to a wide variety of interacting biotic and abiotic stressors, with widespread declines in floral resources and agrochemical exposure being two of the most important. In this study, we used examinations of brain gene expression to explore the sublethal consequences of neonicotinoid pesticide exposure and pollen diet composition in nest-founding bumble bee queens. We demonstrate for the first time that pollen diet composition can influence the strength of bumble bee queen responses to pesticide exposure at the molecular level. Specifically, one pollen mixture in our study appeared to buffer bumble bee queens entirely against the effects of pesticide exposure, with respect to brain gene expression. Additionally, we detected unique effects of pollen diet and sustained (versus more temporary) pesticide exposure on queen gene expression. Our findings support the hypothesis that nutritional status can help buffer animals against the harmful effects of other stressors, including pesticides, and highlight the importance of using molecular approaches to explore sublethal consequences of stressors.
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Affiliation(s)
- Claudineia P Costa
- Department of Entomology, University of California, Riverside, Riverside, CA, USA..
| | - Mar Leza
- Department of Biology (Zoology), University of the Balearic Islands, Cra, Valldemossa, Palma, Illes Balears, Spain
| | | | - Kaleigh Fisher
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| | - Alyssa Vollaro
- IIGB Metabolomics Core Facility, University of California, Riverside, Riverside, CA, USA
| | - Manhoi Hur
- IIGB Metabolomics Core Facility, University of California, Riverside, Riverside, CA, USA
| | - Jay S Kirkwood
- IIGB Metabolomics Core Facility, University of California, Riverside, Riverside, CA, USA
| | - S Hollis Woodard
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
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16
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Anderson AR. An exploratory study of bumble bee ( Bombus) phenologies and plant interactions in agricultural landscapes in central Georgia, USA. J NAT HIST 2022. [DOI: 10.1080/00222933.2022.2095940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- A. R. Anderson
- Independent Researcher (University of Georgia), Asheville, NC, USA
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17
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Dawson BM, Wallman JF, Evans MJ, Barton PS. Insect abundance patterns on vertebrate remains reveal carrion resource quality variation. Oecologia 2022; 198:1043-1056. [PMID: 35294646 PMCID: PMC9056491 DOI: 10.1007/s00442-022-05145-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/23/2022] [Indexed: 11/24/2022]
Abstract
Resource quality is a key driver of species abundance and community structure. Carrion is unique among resources due to its high nutritional quality, rapidly changing nature, and the diverse community of organisms it supports. Yet the role resource quality plays in driving variation in abundance patterns of carrion-associated species remains poorly studied. Here we investigate how species abundances change with a measure of resource change, and interpret these findings to determine how species differ in their association with carrion that changes in quality over time. We conducted field succession experiments using pigs and humans over two winters and one summer. We quantified the effect of total body score, an objective measure of resource change, on adult insect abundance using generalised additive models. For each species, phases of increasing abundance likely indicated attraction to a high-quality resource, and length of abundance maxima indicated optimal oviposition and feeding time. Some species such as the beetle Necrobia rufipes had a rapid spike in abundance, suggesting a narrow window of opportunity for carrion resource exploitation, while species like the wasp Nasonia vitripennis had a gradual change in abundance, indicating a wide window of resource exploitation. Different abundance patterns were also observed between species occurring on pigs and humans, suggesting cadaver type is an important aspect of resource quality. Our findings show that species abundances, unlike species occurrences, can reveal additional detail about species exploitation of carrion and provide information about how resource quality may drive competition and variation in insect community succession.
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Affiliation(s)
- Blake M Dawson
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia.
| | - James F Wallman
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia.,Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Maldwyn J Evans
- Fenner School of Environment and Society, Australian National University, Canberra, ACT, Australia.,Department of Ecosystem Studies, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Philip S Barton
- Future Regions Research Centre, Federation University Australia, Mount Helen, VIC, Australia
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18
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Barraud A, Barascou L, Lefebvre V, Sene D, Le Conte Y, Alaux C, Grillenzoni FV, Corvucci F, Serra G, Costa C, Vanderplanck M, Michez D. Variations in Nutritional Requirements Across Bee Species. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.824750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
With 2,000 species currently recorded in Europe, bees are a highly diversified and efficient group of pollinating insects. They obtain their nutrients from nectar and pollen of flowers. However, the chemical composition of these resources, especially of pollen (e.g., protein, lipid, amino acids, fatty acids, or sterol content), is highly variable among plant species. While it is well-known that bees show interspecific variation in their floral choices, there is a lack of information on the nutritional requirements of different bee species. We therefore developed original experiments in laboratory conditions to evaluate the interspecific variations in bee nutritional requirements. We analyzed the chemical content of eight pollen blends, different in terms of protein, lipid, amino acids, and sterols total concentration and profiles. Each pollen blend was provided to four different bee model species: honey bees (Apis mellifera), bumblebees (Bombus terrestris), mason bees (Osmia bicornis and Osmia cornuta). For each species, specific protocols were used to monitor their development (e.g., weight, timing, survival) and resource collection. Overall, we found that the nutritional requirements across those species are different, and that a low-quality diet for one species is not necessarily low-quality for another one. While honey bees are negatively impacted by diets with a high protein content (~40%), bumblebees and mason bees develop normally on these diets but struggle on diets with a low total amino acid and sterol content, specifically with low concentrations of 24-methylenecholesterol and β-sitosterol. Overall, our study supports the need of conserving and/or introducing plant diversity into managed ecosystems to meet the natural nutritional preferences of bees at species and community level.
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19
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Mola JM, Hemberger J, Kochanski J, Richardson LL, Pearse IS. The Importance of Forests in Bumble Bee Biology and Conservation. Bioscience 2021. [DOI: 10.1093/biosci/biab121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Declines of many bumble bee species have raised concerns because of their importance as pollinators and potential harbingers of declines among other insect taxa. At present, bumble bee conservation is predominantly focused on midsummer flower restoration in open habitats. However, a growing body of evidence suggests that forests may play an important role in bumble bee life history. Compared with open habitats, forests and woody edges provide food resources during phenologically distinct periods, are often preferred nesting and overwintering habitats, and can offer favorable abiotic conditions in a changing climate. Future research efforts are needed in order to anticipate how ongoing changes in forests, such as overbrowsing by deer, plant invasions, and shifting canopy demographics, affect the suitability of these habitats for bumble bees. Forested habitats are increasingly appreciated in the life cycles of many bumble bees, and they deserve greater attention from those who wish to understand bumble bee populations and aid in their conservation.
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Affiliation(s)
- John M Mola
- Fort Collins Science Center, Fort Collins, Colorado, United States
| | - Jeremy Hemberger
- University of California Davis, Davis, California, United States
| | - Jade Kochanski
- University of Wisconsin Madison, Madison, Wisconsin, United States
| | - Leif L Richardson
- Xerces Society for Invertebrate Conservation, Portland, Oregon, United States
| | - Ian S Pearse
- Fort Collins Science Center, Fort Collins, Colorado, United States
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20
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Archer CR, Fähnle J, Pretzner M, Üstüner C, Weber N, Sutter A, Doublet V, Wilfert L. Complex relationship between amino acids, fitness and food intake in Bombus terrestris. Amino Acids 2021; 53:1545-1558. [PMID: 34590185 PMCID: PMC8519840 DOI: 10.1007/s00726-021-03075-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/30/2021] [Indexed: 10/31/2022]
Abstract
The ratio of amino acids to carbohydrates (AA:C) that bumble bees consume has been reported to affect their survival. However, it is unknown how dietary AA:C ratio affects other bumble bee fitness traits (e.g., fecundity, condition) and possible trade-offs between them. Moreover, while individual AAs affect phenotype in many species, the effects of AA blend on bumble bee fitness and food intake are unclear. We test how the AA:C ratio that bumble bees (Bombus terrestris) consume affects their condition (abdomen lipid and dry mass), survival following food removal, and ovarian activation. We then compare ovarian activation and food intake in bees fed identical AA:C ratios, but where the blend of AAs in diets differ, i.e., diets contained the same 10 AAs in an equimolar ratio or in the same ratio as in bee collected pollen. We found that AA:C ratio did not significantly affect survival following food removal or ovarian activation; however, high AA intake increased body mass, which is positively correlated with multiple fitness traits in bumble bees. AA blend (i.e., equimolar versus pollen) did not significantly affect overall ovarian activation or consumption of each experimental diet. However, there was an interaction between AA mix and dietary AA:C ratio affecting survival during the feeding experiment, and signs that there may have been weak, interactive effects of AA mix and AA:C ratio on food consumption. These results suggest that the effect of total AA intake on bumble bee phenotype may depend on the blend of individual AAs in experimental diets. We suggest that research exploring how AA blend affects bumble bee performance and dietary intake is warranted, and highlight that comparing research on bee nutrition is complicated by even subtle variation in experimental diet composition.
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Affiliation(s)
- C Ruth Archer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
| | - Johannes Fähnle
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Maximilian Pretzner
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Cansu Üstüner
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Nina Weber
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Andreas Sutter
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Vincent Doublet
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Lena Wilfert
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany.,College of Life and Environment Sciences, University of Exeter, Tremough Campus, Penryn, TR10 8FL, UK
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21
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Giacomini JJ, Connon SJ, Marulanda D, Adler LS, Irwin RE. The costs and benefits of sunflower pollen diet on bumble bee colony disease and health. Ecosphere 2021. [DOI: 10.1002/ecs2.3663] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Jonathan J. Giacomini
- Department of Applied Ecology North Carolina State University Raleigh North Carolina 27695 USA
| | - Sara J. Connon
- Department of Applied Ecology North Carolina State University Raleigh North Carolina 27695 USA
| | - Daniel Marulanda
- Department of Applied Ecology North Carolina State University Raleigh North Carolina 27695 USA
| | - Lynn S. Adler
- Department of Biology University of Massachusetts Amherst Amherst Massachusetts 01003 USA
| | - Rebecca E. Irwin
- Department of Applied Ecology North Carolina State University Raleigh North Carolina 27695 USA
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22
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Crowley LM, Sadler JP, Pritchard J, Hayward SAL. Elevated CO 2 Impacts on Plant-Pollinator Interactions: A Systematic Review and Free Air Carbon Enrichment Field Study. INSECTS 2021; 12:insects12060512. [PMID: 34206033 PMCID: PMC8227562 DOI: 10.3390/insects12060512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Climate change is having a profound impact on pollination systems, yet we still do not know to what extent increasing concentrations of carbon dioxide (CO2) will directly affect the interactions between plants and their pollinators. We review all the existing published literature on the effect of elevated CO2 (eCO2) on flowering time, nectar and pollen production and plant–pollinator interactions. We also conduct a field experiment to test the effect of eCO2 on bluebells and their pollinators. We found that few studies have assessed the impact of eCO2 on pollination, and our field data found that bluebells flowered on average 6 days earlier under eCO2 conditions. Hoverflies and bumble bees were the main visitors to bluebell flowers, but insect activity was low early in the flowing period. Although we did not find a difference in the number of visits made by insects to bluebell flowers under eCO2, or the amount of seeds those flowers produced, the change in the timing of flowering could mean that a mismatch could develop between bluebells and their pollinators in the future, which would affect pollination success. Abstract The impact of elevated CO2 (eCO2) on plant–pollinator interactions is poorly understood. This study provides the first systematic review of this topic and identifies important knowledge gaps. In addition, we present field data assessing the impact of eCO2 (150 ppm above ambient) on bluebell (Hyacinthoides non-scripta)–pollinator interactions within a mature, deciduous woodland system. Since 1956, only 71 primary papers have investigated eCO2 effects on flowering time, floral traits and pollination, with a mere 3 studies measuring the impact on pollination interactions. Our field experiment documented flowering phenology, flower visitation and seed production, as well as the abundance and phenology of dominant insect pollinators. We show that first and mid-point flowering occurred 6 days earlier under eCO2, but with no change in flowering duration. Syrphid flies and bumble bees were the dominant flower visitors, with peak activity recorded during mid- and late-flowering periods. Whilst no significant difference was recorded in total visitation or seed set between eCO2 and ambient treatments, there were clear patterns of earlier flowering under eCO2 accompanied by lower pollinator activity during this period. This has implications for potential loss of synchrony in pollination systems under future climate scenarios, with associated long-term impacts on abundance and diversity.
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Affiliation(s)
- Liam M. Crowley
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- The Birmingham Institute of Forest Research, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Correspondence: (L.M.C.); (S.A.L.H.); Tel.: +44-(0)121-414-7147 (S.A.L.H.)
| | - Jonathan P. Sadler
- The Birmingham Institute of Forest Research, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- School of Geography, Earth and Environmental Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Jeremy Pritchard
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- The Birmingham Institute of Forest Research, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Scott A. L. Hayward
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- The Birmingham Institute of Forest Research, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Correspondence: (L.M.C.); (S.A.L.H.); Tel.: +44-(0)121-414-7147 (S.A.L.H.)
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23
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Crone MK, Grozinger CM. Pollen protein and lipid content influence resilience to insecticides in honey bees ( Apis mellifera). J Exp Biol 2021; 224:jeb.242040. [PMID: 33758024 DOI: 10.1242/jeb.242040] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/17/2021] [Indexed: 12/19/2022]
Abstract
In honey bees (Apis mellifera), there is growing evidence that the impacts of multiple stressors can be mitigated by quality nutrition. Pollen, which is the primary source of protein and lipids in bees diets, is particularly critical for generating more resilient phenotypes. Here, we evaluate the relationship between pollen protein-to-lipid ratios (P:Ls) and honey bee insecticide resilience. We hypothesized that pollen diets richer in lipids would lead to increased survival in bees exposed to insecticides, as pollen-derived lipids have previously been shown to improve bee resilience to pathogens and parasites. Furthermore, lipid metabolic processes are altered in bees exposed to insecticides.We fed age-matched bees pollen diets of different P:Ls by altering a base pollen by either adding protein (casein powder) or lipids (canola oil) and simulating chronic insecticide exposure by feeding bees an organophosphate (Chlorpyrifos). We also tested pollen diets of naturally different P:Ls to determine if results are consistent. Linear regression analysis revealed that mean survival time for altered diets was best explained by protein concentration (p =0.04 , adjusted R2 =0.92), and that mean survival time for natural diets was best explained by P:L ratio (p =0.008 , adjusted R2 =0.93). Our results indicate that higher ratios of dietary protein to lipid has a negative effect on bee physiology when combined with insecticide exposure, while lower ratios have a positive effect. These results suggest that protein and lipid intake differentially influence insecticide response in bees, laying the groundwork for future studies of metabolic processes and development of improved diets.
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Affiliation(s)
- Makaylee K Crone
- Intercollege Graduate Program in Ecology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences, Pennsylvania State University, USA
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24
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Requier F, Jowanowitsch KK, Kallnik K, Steffan-Dewenter I. Limitation of complementary resources affects colony growth, foraging behavior, and reproduction in bumble bees. Ecology 2020; 101:e02946. [PMID: 31840224 DOI: 10.1002/ecy.2946] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 10/02/2019] [Accepted: 11/12/2019] [Indexed: 11/12/2022]
Abstract
Resource availability in agricultural landscapes has been disturbed for many organisms, including pollinator species. Abundance and diversity in flower availability benefit bee populations; however, little is known about which of protein or carbohydrate resources may limit their growth and reproductive performance. Here, we test the hypothesis of complementary resource limitation using a supplemental feeding approach. We applied this assumption with bumble bees (Bombus terrestris), assuming that colony growth and reproductive performance should depend on the continuous supply of carbohydrates and proteins, through the foraging for nectar and pollen, respectively. We placed wild-caught bumble bee colonies along a landscape gradient of seminatural habitats, and monitored the colonies' weight, foraging activity, and reproductive performance during the whole colony cycle. We performed supplemental feeding as an indicator of landscape resource limitation, using a factorial design consisting of the addition of sugar water (carbohydrate, supplemented or not) crossed by pollen (protein, supplemented or not). Bumble bee colony dynamics showed a clear seasonal pattern with a period of growth followed by a period of stagnation. Higher abundance of seminatural habitats resulted in reducing the proportion of pollen foragers relative to all foragers in both periods, and in improving the reproductive performance of bumble bees. Interestingly, the supplemental feeding of sugar water positively affected the colony weight during the stagnation period, and the supplemental feeding of pollen mitigated the landscape effect on pollen collection investment. Single and combined supplementation of sugar water and pollen increased the positive effect of seminatural habitats on reproductive performance. This study reveals a potential colimitation in pollen and nectar resources affecting foraging behavior and reproductive performance in bumble bees, and indicates that even in mixed agricultural landscapes with higher proportions of seminatural habitats, bumble bee populations face resource limitations. We conclude that the seasonal management of floral resources must be considered in conservation to support bumble bee populations and pollination services in farmlands.
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Affiliation(s)
- Fabrice Requier
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.,Evolution Génome Comportement et Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, 91190, Paris, France
| | - Kim K Jowanowitsch
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Katharina Kallnik
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Ingolf Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
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25
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Bänsch S, Tscharntke T, Wünschiers R, Netter L, Brenig B, Gabriel D, Westphal C. Using ITS2 metabarcoding and microscopy to analyse shifts in pollen diets of honey bees and bumble bees along a mass-flowering crop gradient. Mol Ecol 2020; 29:5003-5018. [PMID: 33030785 DOI: 10.1111/mec.15675] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/12/2020] [Accepted: 09/18/2020] [Indexed: 12/13/2022]
Abstract
Worldwide pollinator declines lead to pollination deficits in crops and wild plants, and managed bees are frequently used to meet the increasing demand for pollination. However, their foraging can be affected by flower availability and colony size. We investigated how mass-flowering oilseed rape (OSR) can influence the pollen resource use of small and large honey bee (Apis mellifera L.) and bumble bee (Bombus terrestris L.) colonies. Colonies were placed adjacent to strawberry fields along a gradient of OSR availability in the landscapes. We used ITS2 metabarcoding to identify the pollen richness based on ITS2 amplicon sequencing and microscopy for quantification of target pollen. Bumble bees collected pollen from more different plant genera than honey bees. In both species, strawberry pollen collection decreased with high OSR availability but was facilitated by increasing strawberry flower cover. Colony size had no effect. The relationship between next-generation sequencing-generated ITS2 amplicon reads and microscopic pollen counts was positive but pollen type-specific. Bumble bees and, to a lesser degree, honey bees collected pollen from a wide variety of plants. Therefore, in order to support pollinators and associated pollination services, future conservation schemes should sustain and promote pollen plant richness in agricultural landscapes. Both bee species responded to the availability of flower resources in the landscape. Although honey bees collected slightly more strawberry pollen than bumble bees, both can be considered as crop pollinators. Metabarcoding could provide similar quantitative information to microscopy, taking into account the pollen types, but there remains high potential to improve the methodological weaknesses.
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Affiliation(s)
- Svenja Bänsch
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany.,Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Teja Tscharntke
- Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Röbbe Wünschiers
- Department of Biotechnology and Chemistry, Mittweida University of Applied Sciences, Mittweida, Germany
| | - Leonie Netter
- Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Bertram Brenig
- Institute of Veterinary Medicine, University of Göttingen, Göttingen, Germany
| | - Doreen Gabriel
- Federal Research Centre for Cultivated Plants, Institute of Crop and Soil Science, Julius Kühn-Institut (JKI), Braunschweig, Germany
| | - Catrin Westphal
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
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26
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Drossart M, Gérard M. Beyond the Decline of Wild Bees: Optimizing Conservation Measures and Bringing Together the Actors. INSECTS 2020; 11:E649. [PMID: 32971790 PMCID: PMC7564822 DOI: 10.3390/insects11090649] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/11/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022]
Abstract
Wild bees are facing a global decline mostly induced by numerous human factors for the last decades. In parallel, public interest for their conservation increased considerably, namely through numerous scientific studies relayed in the media. In spite of this broad interest, a lack of knowledge and understanding of the subject is blatant and reveals a gap between awareness and understanding. While their decline is extensively studied, information on conservation measures is often scattered in the literature. We are now beyond the precautionary principle and experts are calling for effective actions to promote wild bee diversity and the enhancement of environment quality. In this review, we draw a general and up-to-date assessment of the conservation methods, as well as their efficiency and the current projects that try to fill the gaps and optimize the conservation measures. Targeting bees, we focused our attention on (i) the protection and restoration of wild bee habitats, (ii) the conservation measures in anthropogenic habitats, (iii) the implementation of human made tools, (iv) how to deal with invasive alien species, and finally (v) how to communicate efficiently and accurately. This review can be considered as a needed catalyst to implement concrete and qualitative conversation actions for bees.
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Affiliation(s)
- Maxime Drossart
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons (UMONS), Place du Parc 20, B-7000 Mons, Belgium
| | - Maxence Gérard
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons (UMONS), Place du Parc 20, B-7000 Mons, Belgium
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27
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Riaño-Jiménez D, Guerrero M, Alarcón P, Cure JR. Effects of Climate Variability on Queen Production and Pollen Preferences of Neotropical Bumblebee Bombus atratus in a High Andean Suburban Condition. NEOTROPICAL ENTOMOLOGY 2020; 49:586-594. [PMID: 32162246 DOI: 10.1007/s13744-019-00758-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Bombus atratus Franklin is a widely distributed bumblebee of South America. In Colombia, this species is recognized for its ability to adapt to highly disturbed habitats. However, knowledge of its ecology is poorly known, in particular conditions to ensure the long-term conservation of its populations. Identification of pollen resources is an important issue that could be used as a tool to manage and conserve bumblebees. In tropical areas, rainfall patterns could affect floral phenology and therefore the availability of pollen resources. Considering this, the present work aimed to establish the effect of extreme weather conditions (El Niño) in pollen availability, use of pollinic sources, and gyne production in B. atratus colonies. We reared and located 14 B. atratus colonies in a suburban area during a dry season (ENSO "El Niño") and a rainy season (ENSO "La Niña"). We registered time to gyne production and numbers of gynes produced per colony. We extracted pollen samples to establish both its floral origin and its relative abundance. We measured floral offer for each season. The data of pollen use per colony were utilized to perform Bipartite networks. We analyzed the production of gynes and pollen use per season with correlation models and generalized linear models. Colonies of the rainy season produced more gynes and faster. The floral diversity and offer were higher during the rainy season. Successful colonies used specific pollen sources in two seasons, independently of the floral offer. Extreme dry season affected development of B. atratus colonies.
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Affiliation(s)
| | | | - P Alarcón
- Nueva Granada Univ, Cajicá, Colombia
| | - J R Cure
- Nueva Granada Univ, Cajicá, Colombia
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28
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Gervais A, Fournier V, Bélisle M. Agricultural landscape composition affects the development and life expectancy of colonies of
Bombus impatiens. Ecosphere 2020. [DOI: 10.1002/ecs2.3142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- A. Gervais
- Centre de recherche et d’innovation sur les végétaux (CRIV) et Département de phytologie Université Laval 2480 Boulevard Hochelaga Quebec City Québec G1V 0A6 Canada
| | - V. Fournier
- Centre de recherche et d’innovation sur les végétaux (CRIV) et Département de phytologie Université Laval 2480 Boulevard Hochelaga Quebec City Québec G1V 0A6 Canada
| | - M. Bélisle
- Centre d’étude de la forêt (CEF) et Département de biologie Université de Sherbrooke 2500 Boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada
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29
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Gervais A, Courtois È, Fournier V, Bélisle M. Landscape composition and local floral resources influence foraging behavior but not the size of Bombus impatiens Cresson (Hymenoptera: Apidae) workers. PLoS One 2020; 15:e0234498. [PMID: 32584843 PMCID: PMC7316238 DOI: 10.1371/journal.pone.0234498] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 05/27/2020] [Indexed: 11/19/2022] Open
Abstract
Bumble bee communities are strongly disrupted worldwide through the population decline of many species; a phenomenon that has been generally attributed to landscape modification, pesticide use, pathogens, and climate change. The mechanisms by which these causes act on bumble bee colonies are, however, likely to be complex and to involve many levels of organization spanning from the community down to the least understood individual level. Here, we assessed how the morphology, weight and foraging behavior of individual workers are affected by their surrounding landscape. We hypothesized that colonies established in landscapes showing high cover of intensive crops and low cover of flowering crops, as well as low amounts of local floral resources, would produce smaller workers, which would perform fewer foraging trips and collect pollen loads less constant in species composition. We tested these predictions with 80 colonies of commercially reared Bombus impatiens Cresson placed in 20 landscapes spanning a gradient of agricultural intensification in southern Québec, Canada. We estimated weekly rate at which workers entered and exited colonies and captured eight workers per colony over a period of 14 weeks during the spring and summer of 2016. Captured workers had their wing, thorax, head, tibia, and dry weight measured, as well as their pollen load extracted and identified to the lowest possible taxonomic level. We did not detect any effect of landscape habitat composition on worker morphology or body weight, but found that foraging activity decreased with intensive crops. Moreover, higher diversity of local floral resources led to lower pollen constancy in intensively cultivated landscapes. Finally, we found a negative correlation between the size of workers and the diversity of their pollen load. Our results provide additional evidence that conservation actions regarding pollinators in arable landscapes should be made at the landscape rather than at the farm level.
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Affiliation(s)
- Amélie Gervais
- Département de Phytologie, Centre de Recherche et d’Innovation sur les Végétaux (CRIV), Université Laval, Quebec City, Canada
| | - Ève Courtois
- Département de Biologie, Centre d’Étude de la Forêt (CEF), Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Valérie Fournier
- Département de Phytologie, Centre de Recherche et d’Innovation sur les Végétaux (CRIV), Université Laval, Quebec City, Canada
| | - Marc Bélisle
- Département de Biologie, Centre d’Étude de la Forêt (CEF), Université de Sherbrooke, Sherbrooke, Québec, Canada
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30
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Flower traits associated with the visitation patterns of bees. Oecologia 2020; 193:511-522. [PMID: 32495034 DOI: 10.1007/s00442-020-04674-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 05/26/2020] [Indexed: 10/24/2022]
Abstract
Plant-pollinator interactions are partially driven by the expression of plant traits that signal and attract bees to the nutritional resources within flowers. Although multiple physical and chemical floral traits are known to influence the visitation patterns of bees, how distinct bee groups vary in their responses to floral traits has yet to be elucidated. In this study, we used a common garden experiment to test for morphological floral traits associated with pollen quantity at the plant species level, and examined how the visitation patterns of taxonomically and functionally distinct bee groups are related to flower trait characteristics of 39 wildflower species. We also determined how floral traits influence the structure of wild bee communities visiting plants and whether this varies among geographic localities. Our results suggest that floral area is the primary morphological floral trait related to bee visitation of several distinct bee groups, but that wild bee families and functionally distinct bee groups have unique responses to floral trait expression. The composition of the wild bee communities visiting different plants was most strongly associated with variability in floral area, flower height, and the quantity of pollen retained in flowers. Our results inform wildflower habitat management for bees by demonstrating that the visitation patterns of distinct bee taxa can be predicted by floral traits, and highlight that variability in these traits should be considered when selecting plants to support pollinators.
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31
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Saved by the pulse? Separating the effects of total and temporal food abundance on the growth and reproduction of bumble bee microcolonies. Basic Appl Ecol 2020. [DOI: 10.1016/j.baae.2020.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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The Effect of Foraging on Bumble Bees, Bombus terrestris, Reared under Laboratory Conditions. INSECTS 2020; 11:insects11050321. [PMID: 32456127 PMCID: PMC7290516 DOI: 10.3390/insects11050321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 04/06/2020] [Accepted: 05/21/2020] [Indexed: 11/16/2022]
Abstract
Bumble bees are important pollinators broadly used by farmers in greenhouses and under conditions in which honeybee pollination is limited. As such, bumble bees are increasingly being reared for commercial purposes, which brings into question whether individuals reared under laboratory conditions are fully capable of physiological adaptation to field conditions. To understand the changes in bumble bee organism caused by foraging, we compared the fundamental physiological and immunological parameters of Bombus terrestris workers reared under constant optimal laboratory conditions with workers from sister colonies that were allowed to forage for two weeks in the field. Nutritional status and immune response were further determined in wild foragers of B.terrestris that lived under the constant influence of natural stressors. Both wild and laboratory-reared workers subjected to the field conditions had a lower protein concentration in the hemolymph and increased antimicrobial activity, the detection of which was limited in the non-foragers. However, in most of the tested parameters, specifically the level of carbohydrates, antioxidants, total hemocyte concentration in the hemolymph and melanization response, we did not observe any significant differences between bumble bee workers produced in the laboratory and wild animals, nor between foragers and non-foragers. Our results show that bumble bees reared under laboratory conditions can mount a sufficient immune response to potential pathogens and cope with differential food availability in the field, similarly to the wild bumble bee workers.
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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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Pollen Protein: Lipid Macronutrient Ratios May Guide Broad Patterns of Bee Species Floral Preferences. INSECTS 2020; 11:insects11020132. [PMID: 32085627 PMCID: PMC7074338 DOI: 10.3390/insects11020132] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/03/2020] [Accepted: 02/15/2020] [Indexed: 11/26/2022]
Abstract
Pollinator nutritional ecology provides insights into plant–pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous research revealed that pollen protein to lipid ratios (P:L) shape bumble bee foraging preferences among pollen host-plant species, and these preferred ratios link to bumble bee colony health and fitness. Yet, we are still in the early stages of integrating data on P:L ratios across plant and bee species. Here, using a standard laboratory protocol, we present over 80 plant species’ protein and lipid concentrations and P:L values, and we evaluate the P:L ratios of pollen collected by three bee species. We discuss the general phylogenetic, phenotypic, behavioral, and ecological trends observed in these P:L ratios that may drive plant–pollinator interactions; we also present future research questions to further strengthen the field of pollination nutritional ecology. This dataset provides a foundation for researchers studying the nutritional drivers of plant–pollinator interactions as well as for stakeholders developing planting schemes to best support pollinators.
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35
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Simanonok MP, Otto CRV, Smart MD. Do the Quality and Quantity of Honey Bee-Collected Pollen Vary Across an Agricultural Land-Use Gradient? ENVIRONMENTAL ENTOMOLOGY 2020; 49:189-196. [PMID: 31748814 DOI: 10.1093/ee/nvz139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Indexed: 05/27/2023]
Abstract
Pollen is the source of protein for most bee species, yet the quality and quantity of pollen is variable across landscapes and growing seasons. Understanding the role of landscapes in providing nutritious forage to bees is important for pollinator health, particularly in areas undergoing significant land-use change such as in the Northern Great Plains (NGP) region of the United States where grasslands are being converted to row crops. We investigated how the quality and quantity of pollen collected by honey bees (Apis mellifera L. [Hymenoptera: Apidae]) changed with land use and across the growing season by sampling bee-collected pollen from apiaries in North Dakota, South Dakota, and Minnesota, USA, throughout the flowering season in 2015-2016. We quantified protein content and quantity of pollen to investigate how they varied temporally and across a land-use gradient of grasslands to row crops. Neither pollen weight nor crude protein content varied linearly across the land-use gradient; however, there were significant interactions between land use and sampling date across the season, particularly in grasslands. Generally, pollen protein peaked mid-July while pollen weight had two maxima in late-June and late-August. Results suggest that while land use itself may not correlate with the quality or quantity of pollen resources collected by honey bees among our study apiaries, the nutritional landscape of the NGP is seasonally dynamic, especially in certain land covers, and may impose seasonal resource limitations for both managed and native bee species. Furthermore, results indicate periods of qualitative and quantitative pollen dearth may not coincide.
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Affiliation(s)
- Michael P Simanonok
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND
| | - Clint R V Otto
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND
| | - Matthew D Smart
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND
- Department of Entomology, University of Nebraska Lincoln, Lincoln, NE
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36
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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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37
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Ruedenauer FA, Raubenheimer D, Kessner-Beierlein D, Grund-Mueller N, Noack L, Spaethe J, Leonhardt SD. Best be(e) on low fat: linking nutrient perception, regulation and fitness. Ecol Lett 2020; 23:545-554. [PMID: 31943632 DOI: 10.1111/ele.13454] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022]
Abstract
Preventing malnutrition through consuming nutritionally appropriate resources represents a challenge for foraging animals. This is due to often high variation in the nutritional quality of available resources. Foragers consequently need to evaluate different food sources. However, even the same food source can provide a plethora of nutritional and non-nutritional cues, which could serve for quality assessment. We show that bumblebees, Bombus terrestris, overcome this challenge by relying on lipids as nutritional cue when selecting pollen. The bees 'prioritised' lipid perception in learning experiments and avoided lipid consumption in feeding experiments, which supported survival and reproduction. In contrast, survival and reproduction were severely reduced by increased lipid contents. Our study highlights the importance of fat regulation for pollen foraging bumblebees. It also reveals that nutrient perception, nutrient regulation and reproductive fitness can be linked, which represents an effective strategy enabling quick foraging decisions that prevent malnutrition and maximise fitness.
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Affiliation(s)
- Fabian A Ruedenauer
- Department of Animal Ecology and Tropical Biology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany.,Department of Ecology and Ecosystem Management, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - David Raubenheimer
- The Charles Perkins Centre and School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Daniela Kessner-Beierlein
- Department of Animal Ecology and Tropical Biology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Nils Grund-Mueller
- Department of Animal Ecology and Tropical Biology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Lisa Noack
- Department of Animal Ecology and Tropical Biology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Sara D Leonhardt
- Department of Animal Ecology and Tropical Biology, Biozentrum, University of Würzburg, Am Hubland, Würzburg, Germany.,Department of Ecology and Ecosystem Management, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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38
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Simanonok MP, Burkle LA. High-severity wildfire limits available floral pollen quality and bumble bee nutrition compared to mixed-severity burns. Oecologia 2019; 192:489-499. [PMID: 31844986 DOI: 10.1007/s00442-019-04577-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 12/05/2019] [Indexed: 11/30/2022]
Abstract
High-severity wildfires, which can homogenize floral communities, are becoming more common relative to historic mixed-severity fire regimes in the Northern Rockies of the U.S. High-severity wildfire could negatively affect bumble bees, which are typically diet generalists, if floral species of inadequate pollen quality dominate the landscape post-burn. High-severity wildfires often require more time to return to pre-burn vegetation composition, and thus, effects of high-severity burns may persist past initial impacts. We investigated how wildfire severity (mixed- vs. high-severity) and time-since-burn affected available floral pollen quality, corbicular pollen quality, and bumble bee nutrition using percent nitrogen as a proxy for pollen quality and bumble bee nutrition. We found that community-weighted mean floral pollen nitrogen, corbicular pollen nitrogen, and bumble bee nitrogen were greater on average by 0.82%N, 0.60%N, and 1.16%N, respectively, in mixed-severity burns. This pattern of enhanced floral pollen nitrogen in mixed-severity burns was likely driven by the floral community, as community-weighted mean floral pollen percent nitrogen explained 87.4% of deviance in floral community composition. Only bee percent nitrogen varied with time-since-burn, increasing by 0.33%N per year. If these patterns persist across systems, our findings suggest that although wildfire is an essential ecosystem process, there are negative early successional impacts of high-severity wildfires on bumble bees and potentially on other pollen-dependent organisms via reductions in available pollen quality and nutrition. This work examines a previously unexplored pathway for how disturbances can influence native bee success via altering the nutritional landscape of pollen.
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Affiliation(s)
- Michael P Simanonok
- Department of Ecology, Montana State University, Bozeman, MT, USA. .,U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND, USA.
| | - Laura A Burkle
- Department of Ecology, Montana State University, Bozeman, MT, USA
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39
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López-Uribe MM, Ricigliano VA, Simone-Finstrom M. Defining Pollinator Health: A Holistic Approach Based on Ecological, Genetic, and Physiological Factors. Annu Rev Anim Biosci 2019; 8:269-294. [PMID: 31618045 DOI: 10.1146/annurev-animal-020518-115045] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Evidence for global bee population declines has catalyzed a rapidly evolving area of research that aims to identify the causal factors and to effectively assess the status of pollinator populations. The term pollinator health emerged through efforts to understand causes of bee decline and colony losses, but it lacks a formal definition. In this review, we propose a definition for pollinator health and synthesize the available literature on the application of standardized biomarkers to assess health at the individual, colony, and population levels. We focus on biomarkers in honey bees, a model species, but extrapolate the potential application of these approaches to monitor the health status of wild bee populations. Biomarker-guided health measures can inform beekeeper management decisions, wild bee conservation efforts, and environmental policies. We conclude by addressing challenges to pollinator health from a One Health perspective that emphasizes the interplay between environmental quality and human, animal, and bee health.
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Affiliation(s)
- Margarita M López-Uribe
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania 16802, USA;
| | - Vincent A Ricigliano
- Honey Bee Breeding, Genetics and Physiology Research, USDA-ARS, Baton Rouge, Louisiana 70820, USA; ,
| | - Michael Simone-Finstrom
- Honey Bee Breeding, Genetics and Physiology Research, USDA-ARS, Baton Rouge, Louisiana 70820, USA; ,
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40
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Campbell JW, Bammer M, Bustamante TA, Ellis JD. The Health of Commercial Bombus impatiens (Hymenoptera: Apidae) Colonies After Foraging in Florida Watermelon and Blueberry. ENVIRONMENTAL ENTOMOLOGY 2019; 48:1197-1202. [PMID: 31237607 DOI: 10.1093/ee/nvz081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Bumble bees are commonly used to provide pollination services within crop fields and greenhouses, with Bombus impatiens Cresson; Hymenoptera: Apidae, a bee native to the eastern United States, being the only managed bumble bee available commercially in the United States. Although many researchers have explored managed bumble bees' ability to pollinate various crops and the potential spread of pathogens by managed bumble bees, scant research is available on how managed bumble bee colony health is affected after foraging within crop fields. We measured 10 B. impatiens colony health parameters: 1) colony weight; number of 2) honey/pollen pots, 3) workers, 4) queens, 5) drones, 6) immatures, 7) eggs; and weight of 8) workers, 9) drones, and 10) queens from colonies that foraged within blueberry or watermelon fields, and compared them to control colonies that were purchased and immediately frozen upon receipt. Bees that foraged within blueberry increased in colony weight and in the number of immatures and eggs during the bloom period compared to control colonies. In contrast, bee colonies placed within watermelon decreased in colony weight, number of workers and immature bees, and individual bee weight compared to control colonies. Blueberry appeared to provide bees with sufficient nectar and pollen, whereas watermelon may not have provided adequate resources for the bees. Bees foraging within watermelon were probably forced to search for other sources of pollen and nectar, resulting in colony health parameter declines. Our data suggest that some crops (e.g., blueberry) can support managed B. impatiens, potentially adding to localized bumble bee populations, while others (e.g., watermelon) cannot.
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Affiliation(s)
- Joshua W Campbell
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | - Mary Bammer
- Entomology and Nematology Department, University of Florida, Steinmetz Hall, Gainesville, FL
| | - Tomas A Bustamante
- Entomology and Nematology Department, University of Florida, Steinmetz Hall, Gainesville, FL
| | - James D Ellis
- Entomology and Nematology Department, University of Florida, Steinmetz Hall, Gainesville, FL
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Malfi RL, Crone E, Williams N. Demographic benefits of early season resources for bumble bee (B. vosnesenskii) colonies. Oecologia 2019; 191:377-388. [PMID: 31486888 DOI: 10.1007/s00442-019-04472-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/18/2019] [Indexed: 01/28/2023]
Abstract
The temporal distribution of resources is an important aspect of habitat quality that can substantially impact population success. Although it is widely accepted that floral resources directly influence wild bee population sizes, we lack experimental data evaluating how resource availability affects colony growth via demographic mechanisms. To achieve this, we tracked marked individuals in bumble bee (Bombus vosnesenskii) colonies to evaluate whether worker survival and reproduction responded to experimentally elevated forage early in colony development. Specifically, we assessed the effect of early resource environment on worker and sexual offspring production, and the survival and body size of individual workers. We also assessed whether responses of colonies differed when exposed to higher or lower resource environments at a relatively smaller (~ 10 workers) or larger (~ 20 workers) size. Resource supplementation always resulted in greater total offspring and male production; however, the influence of supplementation on worker production and quality depended on colony size at the start of supplementation. Among colonies that were initially smaller, colonies that were supplemented produced fewer but larger bodied and longer lived workers compared to control counterparts. Among colonies that were initially larger, colonies that were supplemented produced more workers than corresponding controls, but without changes to worker quality. Collectively, these results provide clear experimental evidence that greater resource availability early in colony development increases overall productivity, and indicate that colonies may pursue different allocation strategies in response to the resource environment, investing in more or better workers.
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Affiliation(s)
- Rosemary L Malfi
- Department of Entomology and Nematology, University of California Davis, Briggs Hall, Room 367, Davis, CA, 95616, USA.
| | - Elizabeth Crone
- Department of Biology, Tufts University, Medford, MA, 02155, USA
| | - Neal Williams
- Department of Entomology and Nematology, University of California Davis, Briggs Hall, Room 367, Davis, CA, 95616, USA
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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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Nürnberger F, Keller A, Härtel S, Steffan‐Dewenter I. Honey bee waggle dance communication increases diversity of pollen diets in intensively managed agricultural landscapes. Mol Ecol 2019; 28:3602-3611. [DOI: 10.1111/mec.15156] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/04/2019] [Accepted: 06/13/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Fabian Nürnberger
- Department of Animal Ecology and Tropical Biology, Biocenter University of Würzburg Würzburg Germany
- Thünen Institute of Biodiversity Braunschweig Germany
| | - Alexander Keller
- Department of Bioinformatics and Center for Computational and Theoretical Biology, Biocenter University of Würzburg Würzburg Germany
| | - Stephan Härtel
- Department of Animal Ecology and Tropical Biology, Biocenter University of Würzburg Würzburg Germany
| | - Ingolf Steffan‐Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter University of Würzburg Würzburg Germany
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Spivak M, Goblirsch M, Simone-Finstrom M. Social-medication in bees: the line between individual and social regulation. CURRENT OPINION IN INSECT SCIENCE 2019; 33:49-55. [PMID: 31358195 DOI: 10.1016/j.cois.2019.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/16/2019] [Accepted: 02/23/2019] [Indexed: 06/10/2023]
Abstract
We use the term social-medication to describe the deliberate consumption or use of plant compounds by social insects that are detrimental to a pathogen or parasite at the colony level, result in increased inclusive fitness to the colony, and have potential costs either at the individual or colony level in the absence of parasite infection. These criteria for social-medication differ from those for self-medication in that inclusive fitness costs and benefits are distinguished from individual costs and benefits. The consumption of pollen and nectar may be considered a form of social immunity if they help fight infection, resulting in a demonstrated increase in colony health and survival. However, the dietary use of pollen and nectar per se is likely not a form of social-medication unless there is a detriment or cost to their consumption in the absence of parasite infection, such as when they contain phytochemicals that are toxic at certain doses. We provide examples among social bees (bumblebees, stingless bees and honey bees) in which the consumption or use of plant compounds have a demonstrated role in parasite defense and health of the colony. We indicate where more work is needed to distinguish between prophylactic and therapeutic effects of these compounds, and whether the effects are observed at the individual or colony level.
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Affiliation(s)
- Marla Spivak
- Department of Entomology, 1980 Folwell Ave, University of Minnesota, St Paul, MN, 55108, United States.
| | - Michael Goblirsch
- Department of Entomology, 1980 Folwell Ave, University of Minnesota, St Paul, MN, 55108, United States
| | - Michael Simone-Finstrom
- USDA-ARS, Honey Bee Breeding, Genetics, and Physiology Research, 1157 Ben Hur Rd Baton Rouge, LA, 70820, United States
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