1
|
Dobelmann J, Manley R, Wilfert L. Caught in the act: the invasion of a viral vector changes viral prevalence and titre in native honeybees and bumblebees. Biol Lett 2024; 20:20230600. [PMID: 38715462 PMCID: PMC11135380 DOI: 10.1098/rsbl.2023.0600] [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: 12/22/2023] [Revised: 03/04/2024] [Accepted: 04/02/2024] [Indexed: 05/31/2024] Open
Abstract
Novel transmission routes change pathogen landscapes and may facilitate disease emergence. The varroa mite is a virus vector that switched to western honeybees at the beginning of the last century, leading to hive mortality, particularly in combination with RNA viruses. A recent invasion of varroa on the French island of Ushant introduced vector-mediated transmission to one of the last varroa-naive native honeybee populations and caused rapid changes in the honeybee viral community. These changes were characterized by a drastic increase in deformed wing virus type B prevalence and titre in honeybees, as well as knock-on effects in bumblebees, particularly in the year following the invasion. Slow bee paralysis virus also appeared in honeybees and bumblebees, with a 1 year delay, while black queen cell virus declined in honeybees. This study highlights the rapid and far-reaching effects of vector-borne transmission that can extend beyond the directly affected host species, and that the direction of the effect depends on the pathogen's virulence.
Collapse
Affiliation(s)
- Jana Dobelmann
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, Ulm89081, Germany
| | | | - Lena Wilfert
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, Ulm89081, Germany
| |
Collapse
|
2
|
Streicher T, Brinker P, Tragust S, Paxton RJ. Host Barriers Limit Viral Spread in a Spillover Host: A Study of Deformed Wing Virus in the Bumblebee Bombus terrestris. Viruses 2024; 16:607. [PMID: 38675948 PMCID: PMC11053533 DOI: 10.3390/v16040607] [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: 03/30/2024] [Revised: 04/13/2024] [Accepted: 04/13/2024] [Indexed: 04/28/2024] Open
Abstract
The transmission of pathogens from reservoir to recipient host species, termed pathogen spillover, can profoundly impact plant, animal, and public health. However, why some pathogens lead to disease emergence in a novel species while others fail to establish or do not elicit disease is often poorly understood. There is strong evidence that deformed wing virus (DWV), an (+)ssRNA virus, spills over from its reservoir host, the honeybee Apis mellifera, into the bumblebee Bombus terrestris. However, the low impact of DWV on B. terrestris in laboratory experiments suggests host barriers to virus spread in this recipient host. To investigate potential host barriers, we followed the spread of DWV genotype B (DWV-B) through a host's body using RT-PCR after experimental transmission to bumblebees in comparison to honeybees. Inoculation was per os, mimicking food-borne transmission, or by injection into the bee's haemocoel, mimicking vector-based transmission. In honeybees, DWV-B was present in both honeybee faeces and haemolymph within 3 days of inoculation per os or by injection. In contrast, DWV-B was not detected in B. terrestris haemolymph after inoculation per os, suggesting a gut barrier that hinders DWV-B's spread through the body of a B. terrestris. DWV-B was, however, detected in B. terrestris faeces after injection and feeding, albeit at a lower abundance than that observed for A. mellifera, suggesting that B. terrestris sheds less DWV-B than A. mellifera in faeces when infected. Barriers to viral spread in B. terrestris following oral infection may limit DWV's impact on this spillover host and reduce its contribution to the community epidemiology of DWV.
Collapse
Affiliation(s)
- Tabea Streicher
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Pina Brinker
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103 Leipzig, Germany
| | - Simon Tragust
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Robert J. Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103 Leipzig, Germany
| |
Collapse
|
3
|
Zhang Z, Villalobos EM, Nikaido S, Martin SJ. Seasonal Variability in the Prevalence of DWV Strains in Individual Colonies of European Honeybees in Hawaii. INSECTS 2024; 15:219. [PMID: 38667349 PMCID: PMC11050578 DOI: 10.3390/insects15040219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/19/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024]
Abstract
The most prevalent viral pathogen of honeybees is Deformed Wing Virus (DWV) and its two most widely studied and common master-variants are DWV-A and DWV-B. The prevalence of DWV variants in the UK and in the US is changing, with the prevalence of the DWV-A strain declining and DWV-B increasing over time. In 2012, only DWV-A was detected on the Hawaiian Islands of Oahu. In this study we focused on a colony-level survey of DWV strains in a single apiary and examined the prevalence of DWV variants over the course of two years. In 2018 and 2019, a total of 16 colonies underwent viral testing in January, May, and September. Of those 16 colonies, four were monitored in both 2018 and 2019. Individual colonies showed variability of DWV master variants throughout the sampling period. DWV-A was consistently detected; however, the detection of DWV-B was variable across time in individual colonies. Ultimately, this study demonstrated a seasonal variation in both viral prevalence and load for DWV-B, providing a perspective on the dynamic nature of DWV master variants emerging in Hawaii.
Collapse
Affiliation(s)
- Zhening Zhang
- Department of Plant and Environmental Protection Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii, 3050 Maile Way, 310 Gilmore Hall, Honolulu, HI 96822, USA; (E.M.V.); (S.N.)
| | - Ethel M. Villalobos
- Department of Plant and Environmental Protection Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii, 3050 Maile Way, 310 Gilmore Hall, Honolulu, HI 96822, USA; (E.M.V.); (S.N.)
| | - Scott Nikaido
- Department of Plant and Environmental Protection Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii, 3050 Maile Way, 310 Gilmore Hall, Honolulu, HI 96822, USA; (E.M.V.); (S.N.)
| | - Stephen J. Martin
- School of Environment and Life Sciences, The University of Salford, Manchester M5 4WT, UK;
| |
Collapse
|
4
|
Babin A, Schurr F, Delannoy S, Fach P, Huyen Ton Nu Nguyet M, Bougeard S, de Miranda JR, Rundlöf M, Wintermantel D, Albrecht M, Attridge E, Bottero I, Cini E, Costa C, De la Rúa P, Di Prisco G, Dominik C, Dzul D, Hodge S, Klein AM, Knapp J, Knauer AC, Mänd M, Martínez-López V, Medrzycki P, Pereira-Peixoto MH, Potts SG, Raimets R, Schweiger O, Senapathi D, Serrano J, Stout JC, Tamburini G, Brown MJF, Laurent M, Rivière MP, Chauzat MP, Dubois E. Distribution of infectious and parasitic agents among three sentinel bee species across European agricultural landscapes. Sci Rep 2024; 14:3524. [PMID: 38347035 PMCID: PMC10861508 DOI: 10.1038/s41598-024-53357-w] [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: 06/12/2023] [Accepted: 01/31/2024] [Indexed: 02/15/2024] Open
Abstract
Infectious and parasitic agents (IPAs) and their associated diseases are major environmental stressors that jeopardize bee health, both alone and in interaction with other stressors. Their impact on pollinator communities can be assessed by studying multiple sentinel bee species. Here, we analysed the field exposure of three sentinel managed bee species (Apis mellifera, Bombus terrestris and Osmia bicornis) to 11 IPAs (six RNA viruses, two bacteria, three microsporidia). The sentinel bees were deployed at 128 sites in eight European countries adjacent to either oilseed rape fields or apple orchards during crop bloom. Adult bees of each species were sampled before their placement and after crop bloom. The IPAs were detected and quantified using a harmonised, high-throughput and semi-automatized qPCR workflow. We describe differences among bee species in IPA profiles (richness, diversity, detection frequencies, loads and their change upon field exposure, and exposure risk), with no clear patterns related to the country or focal crop. Our results suggest that the most frequent IPAs in adult bees are more appropriate for assessing the bees' IPA exposure risk. We also report positive correlations of IPA loads supporting the potential IPA transmission among sentinels, suggesting careful consideration should be taken when introducing managed pollinators in ecologically sensitive environments.
Collapse
Affiliation(s)
- Aurélie Babin
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France.
| | - Frank Schurr
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France
| | - Sabine Delannoy
- IdentyPath Genomics Platform, Food Safety Laboratory, ANSES, 94701, Maisons-Alfort, France
| | - Patrick Fach
- IdentyPath Genomics Platform, Food Safety Laboratory, ANSES, 94701, Maisons-Alfort, France
| | | | - Stéphanie Bougeard
- ANSES, Ploufragan-Plouzané-Niort Laboratory, Epidemiology and Welfare, France
| | - Joachim R de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, 75007, Uppsala, Sweden
| | - Maj Rundlöf
- Department of Biology, Lund University, Lund, Sweden
| | - Dimitry Wintermantel
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Straße 4, 79106, Freiburg, Germany
| | - Matthias Albrecht
- Agroecology and Environment, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Eleanor Attridge
- Federation of Irish Beekeepers' Associations, Tullamore, Ireland
| | - Irene Bottero
- Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Elena Cini
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, UK
| | - Cecilia Costa
- CREA Research Centre for Agriculture and Environment, Via di Corticella 133, 40128, Bologna, Italy
| | - Pilar De la Rúa
- Department of Zoology and Physical Anthropology, Faculty of Veterinary, University of Murcia, 30100, Murcia, Spain
| | - Gennaro Di Prisco
- CREA Research Centre for Agriculture and Environment, Via di Corticella 133, 40128, Bologna, Italy
- Institute for Sustainable Plant Protection, The Italian National Research Council, Piazzale E. Ferni 1, 80055, Portici, Napoli, Italy
| | - Christophe Dominik
- UFZ-Helmholtz Centre for Environmental Research, Department of Community Ecology, 06120, Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103, Leipzig, Germany
| | - Daniel Dzul
- Department of Zoology and Physical Anthropology, Faculty of Veterinary, University of Murcia, 30100, Murcia, Spain
| | - Simon Hodge
- Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Alexandra-Maria Klein
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Straße 4, 79106, Freiburg, Germany
| | - Jessica Knapp
- Department of Biology, Lund University, Lund, Sweden
- Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Anina C Knauer
- Agroecology and Environment, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Marika Mänd
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Vicente Martínez-López
- Department of Zoology and Physical Anthropology, Faculty of Veterinary, University of Murcia, 30100, Murcia, Spain
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Crown Street, Bioscience Building, L69 7ZB, Liverpool, UK
| | - Piotr Medrzycki
- CREA Research Centre for Agriculture and Environment, Via di Corticella 133, 40128, Bologna, Italy
| | - Maria Helena Pereira-Peixoto
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Straße 4, 79106, Freiburg, Germany
| | - Simon G Potts
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, UK
| | - Risto Raimets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Oliver Schweiger
- UFZ-Helmholtz Centre for Environmental Research, Department of Community Ecology, 06120, Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103, Leipzig, Germany
| | - Deepa Senapathi
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, UK
| | - José Serrano
- Department of Zoology and Physical Anthropology, Faculty of Veterinary, University of Murcia, 30100, Murcia, Spain
| | - Jane C Stout
- Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Giovanni Tamburini
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Straße 4, 79106, Freiburg, Germany
- University of Bari, Department of Soil, Plant and Food Sciences (DiSSPA-Entomology and Zoology), Bari, Italy
| | - Mark J F Brown
- Centre for Ecology, Evolution & Behaviour, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, UK
| | - Marion Laurent
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France
| | - Marie-Pierre Rivière
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France
| | - Marie-Pierre Chauzat
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France
- Paris-Est University, ANSES, Laboratory for Animal Health, 94701, Maisons-Alfort, France
| | - Eric Dubois
- ANSES, Sophia Antipolis Laboratory, Unit of Honey bee Pathology, 06902, Sophia Antipolis, France.
| |
Collapse
|
5
|
Sharpe SR, Morrow JL, Cook JM, Papanicolaou A, Riegler M. Transmission mode predicts coinfection patterns of insect-specific viruses in field populations of the Queensland fruit fly. Mol Ecol 2024; 33:e17226. [PMID: 38018898 DOI: 10.1111/mec.17226] [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: 05/03/2023] [Revised: 10/05/2023] [Accepted: 11/13/2023] [Indexed: 11/30/2023]
Abstract
Insect-specific viruses (ISVs) can affect insect health and fitness, but can also interact with other insect-associated microorganisms. Despite this, ISVs are often studied in isolation from each other, in laboratory populations. Consequently, their diversity, prevalence and associations with other viruses in field populations are less known, yet these parameters are important to understanding virus epidemiology. To help address this knowledge gap, we assessed the diversity, prevalence and coinfections of three ISVs (horizontally transmitted cripavirus, biparentally transmitted sigmavirus and maternally transmitted iflavirus) in 29 field populations of Queensland fruit fly, Australia's most significant horticultural pest, in the context of their different transmission modes. We detected new virus variant diversity. In contrast to the very high virus prevalence in laboratory populations, 46.8% of 293 field flies carried one virus and 4.8% had two viruses. Cripavirus and sigmavirus occurred in all regions, while iflavirus was restricted to subtropical and tropical regions. Cripavirus was most prevalent (37.5%), followed by sigmavirus (13.7%) and iflavirus (4.4%). Cripavirus coinfected some flies with either one of the two vertically transmitted viruses. However, sigmavirus did not coinfect individuals with iflavirus. Three different modelling approaches detected negative association patterns between sigmavirus and iflavirus, consistent with the absence of such coinfections in laboratory populations. This may be linked with their maternal transmission and the ineffective paternal transmission of sigmavirus. Furthermore, we found that, unlike sigmavirus and iflavirus, cripavirus load was higher in laboratory than field flies. Laboratory and mass-rearing conditions may increase ISV prevalence and load due to increased transmission opportunities. We conclude that a combination of field and laboratory studies is needed to uncover ISV interactions and further our understanding of ISV epidemiology.
Collapse
Affiliation(s)
- Stephen R Sharpe
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Jennifer L Morrow
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - James M Cook
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Alexie Papanicolaou
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Markus Riegler
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| |
Collapse
|
6
|
Doublet V, Oddie MAY, Mondet F, Forsgren E, Dahle B, Furuseth-Hansen E, Williams GR, De Smet L, Natsopoulou ME, Murray TE, Semberg E, Yañez O, de Graaf DC, Le Conte Y, Neumann P, Rimstad E, Paxton RJ, de Miranda JR. Shift in virus composition in honeybees ( Apis mellifera) following worldwide invasion by the parasitic mite and virus vector Varroa destructor. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231529. [PMID: 38204792 PMCID: PMC10776227 DOI: 10.1098/rsos.231529] [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: 10/09/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024]
Abstract
Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Varroa destructor that acts as potent virus vector among honeybees Apis mellifera, we investigated the impact of its recent global spread on the viral community of honeybees in a retrospective study of historical samples. We hypothesized that the vector has had an effect on the epidemiology of several bee viruses, potentially altering their transmissibility and/or virulence, and consequently their prevalence, abundance, or both. To test this, we quantified the prevalence and loads of 14 viruses from honeybee samples collected in mite-free and mite-infested populations in four independent geographical regions. The presence of the mite dramatically increased the prevalence and load of deformed wing virus, a cause of unsustainably high colony losses. In addition, several other viruses became more prevalent or were found at higher load in mite-infested areas, including viruses not known to be actively varroa-transmitted, but which may increase opportunistically in varroa-parasitized bees.
Collapse
Affiliation(s)
- Vincent Doublet
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Melissa A. Y. Oddie
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Fanny Mondet
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Eva Forsgren
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Bjørn Dahle
- Norwegian Beekeepers Association, Kløfta 2040, Norway
| | - Elisabeth Furuseth-Hansen
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Geoffrey R. Williams
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
- Entomology & Plant Pathology, Auburn University, Auburn, AL 36832, USA
| | - Lina De Smet
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Myrsini E. Natsopoulou
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Tomás E. Murray
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
| | - Emilia Semberg
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | - Orlando Yañez
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Dirk C. de Graaf
- Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium
| | - Yves Le Conte
- INRAE, UR 406 Abeilles et Environnement, Avignon 84914, France
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern 3097, Switzerland
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Ås 1432, Norway
| | - Robert J. Paxton
- Institute for Biology, Martin Luther University Halle-Wittenberg, Halle (Saale) 061200, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Germany
| | - Joachim R. de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| |
Collapse
|
7
|
Ng WH, Myers CR, McArt S, Ellner SP. A Time for Every Purpose: Using Time-Dependent Sensitivity Analysis to Help Understand and Manage Dynamic Ecological Systems. Am Nat 2023; 202:630-654. [PMID: 37963117 DOI: 10.1086/726143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
AbstractSensitivity analysis is often used to help understand and manage ecological systems by assessing how a constant change in vital rates or other model parameters might affect the management outcome. This allows the manager to identify the most favorable course of action. However, realistic changes are often localized in time-for example, a short period of culling leads to a temporary increase in the mortality rate over the period. Hence, knowing when to act may be just as important as knowing what to act on. In this article, we introduce the method of time-dependent sensitivity analysis (TDSA) that simultaneously addresses both questions. We illustrate TDSA using three case studies: transient dynamics in static disease transmission networks, disease dynamics in a reservoir species with seasonal life history events, and endogenously driven population cycles in herbivorous invertebrate forest pests. We demonstrate how TDSA often provides useful biological insights, which are understandable on hindsight but would not have been easily discovered without the help of TDSA. However, as a caution, we also show how TDSA can produce results that mainly reflect uncertain modeling choices and are therefore potentially misleading. We provide guidelines to help users maximize the utility of TDSA while avoiding pitfalls.
Collapse
|
8
|
McCormick EC, Cohen OR, Dolezal AG, Sadd BM. Consequences of microsporidian prior exposure for virus infection outcomes and bumble bee host health. Oecologia 2023:10.1007/s00442-023-05394-x. [PMID: 37284861 DOI: 10.1007/s00442-023-05394-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 05/24/2023] [Indexed: 06/08/2023]
Abstract
Host-parasite interactions do not occur in a vacuum, but in connected multi-parasite networks that can result in co-exposures and coinfections of individual hosts. These can affect host health and disease ecology, including disease outbreaks. However, many host-parasite studies examine pairwise interactions, meaning we still lack a general understanding of the influence of co-exposures and coinfections. Using the bumble bee Bombus impatiens, we study the effects of larval exposure to a microsporidian Nosema bombi, implicated in bumble bee declines, and adult exposure to Israeli Acute Paralysis Virus (IAPV), an emerging infectious disease from honey bee parasite spillover. We hypothesize that infection outcomes will be modified by co-exposure or coinfection. Nosema bombi is a potentially severe, larval-infecting parasite, and we predict that prior exposure will result in decreased host resistance to adult IAPV infection. We predict double parasite exposure will also reduce host tolerance of infection, as measured by host survival. Although our larval Nosema exposure mostly did not result in viable infections, it partially reduced resistance to adult IAPV infection. Nosema exposure also negatively affected survival, potentially due to a cost of immunity in resisting the exposure. There was a significant negative effect of IAPV exposure on survivorship, but prior Nosema exposure did not alter this survival outcome, suggesting increased tolerance given the higher IAPV infections in the bees previously exposed to Nosema. These results again demonstrate that infection outcomes can be non-independent when multiple parasites are present, even when exposure to one parasite does not result in a substantial infection.
Collapse
Affiliation(s)
- Elyse C McCormick
- School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA
| | - Olivia R Cohen
- School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA
| | - Adam G Dolezal
- School of Integrated Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ben M Sadd
- School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA.
| |
Collapse
|
9
|
Kandel M, Paxton RJ, Al Naggar Y. Nationwide Screening for Bee Viruses in Apis mellifera Colonies in Egypt. INSECTS 2023; 14:172. [PMID: 36835740 PMCID: PMC9964814 DOI: 10.3390/insects14020172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Honey bees are essential for crop and wild plant pollination. However, many countries have reported high annual colony losses caused by multiple possible stressors. Diseases, particularly those caused by viruses, are a major cause of colony losses. However, little is known about the prevalence of honey bee pathogens, particularly virus prevalence, in Egyptian honey bees. To address this shortfall, we determined the prevalence of widespread bee viruses in honey bee colonies in Egypt-whether it is affected by geography, the season, or infestation with Varroa destructor (varroa) mites. Honey bee worker samples were collected from 18 geographical regions across Egypt during two seasons: winter and summer of 2021. Three apiaries were chosen in each region, and a pooled sample of 150 worker bees was collected from five colonies in each apiary then screened by qPCR for 10 viral targets: acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV) genotypes A (DWV-A), B (DWV-B) and D (Egyptian bee virus), Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), sacbrood virus (SBV), and slow bee paralysis virus (SBPV). Our results revealed that DWV-A was the most prevalent virus, followed by BQCV and ABPV; the DWV genotype now spreading across the world, DWV-B, was not detected. There was no difference in varroa infestation rates as well as virus prevalence between winter and summer. However, colonies infected with BQCV had a significantly higher varroa count (adjusted p < 0.05) in the winter season, indicating that there is a seasonal association between the intensity of infestation by varroa and the presence of this virus. We provide data on the current virus prevalence in Egypt, which could assist in the protection of Egypt's beekeeping industry. Moreover, our study aids in the systematic assessment of the global honey bee virome by filling a knowledge gap about the prevalence of honey bee viruses in Egypt.
Collapse
Affiliation(s)
- Mohamed Kandel
- Plant Protection and Molecular Diagnosis, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
| | - Robert J. Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Yahya Al Naggar
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
- Zoology Department, Faculty of Science, Tanta University, Tanta 31527, Egypt
| |
Collapse
|
10
|
Fearon ML, Wood CL, Tibbetts EA. Habitat quality influences pollinator pathogen prevalence through both habitat-disease and biodiversity-disease pathways. Ecology 2023; 104:e3933. [PMID: 36448518 PMCID: PMC10078577 DOI: 10.1002/ecy.3933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 09/29/2022] [Accepted: 10/20/2022] [Indexed: 12/03/2022]
Abstract
The dilution effect hypothesis posits that increasing biodiversity reduces infectious disease transmission. Here, we propose that habitat quality might modulate this negative biodiversity-disease relationship. Habitat may influence pathogen prevalence directly by affecting host traits like nutrition and immune response (we coined the term "habitat-disease relationship" to describe this phenomenon) or indirectly by changing host biodiversity (biodiversity-disease relationship). We used a path model to test the relative strength of links between habitat, biodiversity, and pathogen prevalence in a pollinator-virus system. High-quality habitat metrics were directly associated with viral prevalence, providing evidence for a habitat-disease relationship. However, the strength and direction of specific habitat effects on viral prevalence varied based on the characteristics of the habitat, host, and pathogen. In general, more natural area and richness of land-cover types were directly associated with increased viral prevalence, whereas greater floral density was associated with reduced viral prevalence. More natural habitat was also indirectly associated with reduced prevalence of two key viruses (black queen cell virus and deformed wing virus) via increased pollinator species richness, providing evidence for a habitat-mediated dilution effect on viral prevalence. Biodiversity-disease relationships varied across viruses, with the prevalence of sacbrood virus not being associated with any habitat quality or pollinator community metrics. Across all viruses and hosts, habitat-disease and biodiversity-disease paths had effects of similar magnitude on viral prevalence. Therefore, habitat quality is a key driver of variation in pathogen prevalence among communities via both direct habitat-disease and indirect biodiversity-disease pathways, though the specific patterns varied among different viruses and host species. Critically, habitat-disease relationships could either contribute to or obscure dilution effects in natural systems depending on the relative strength and direction of the habitat-disease and biodiversity-disease pathways in that host-pathogen system. Therefore, habitat may be an important driver in the complex interactions between hosts and pathogens.
Collapse
Affiliation(s)
- Michelle L Fearon
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| | - Elizabeth A Tibbetts
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
11
|
Tian JX, Tsai WS, Sung IH. A Novel Variant of Deformed Wing Virus (DWV) from the Invasive Honeybee Apis florea (Apidae, Hymenoptera) and Its Ectoparasite Euvarroa sinhai (Acarina, Mesostigmata) in Taiwan. INSECTS 2023; 14:103. [PMID: 36835672 PMCID: PMC9958760 DOI: 10.3390/insects14020103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The invasion of Apis florea in Taiwan was first recorded in 2017. The deformed wing virus (DWV) has been identified as a common bee virus in apiculture around the world. Ectoparasitic mites are the main DWV vector for horizontal transmission. However, there are few studies about the ectoparasitic mite of Euvarroa sinhai, which has been found in A. florea. In this study, the prevalence of DWV among four hosts, including A. florea, Apis mellifera, E. sinhai, and Varroa destructor, was determined. The results showed that a high DWV-A prevalence rate in A. florea, ranging from 69.2% to 94.4%, was detected. Additionally, the genome of DWV isolates was sequenced and subjected to phylogenetic analysis based on the complete polyprotein sequence. Furthermore, isolates from A. florea and E. sinhai both formed a monophyletic group for the DWV-A lineage, and the sequence identity was 88% between the isolates and DWV-A reference strains. As noted above, two isolates could be the novel DWV strain. It cannot be excluded that novel DWV strains could pose an indirect threat to sympatric species, such as A. mellifera and Apis cerana.
Collapse
|
12
|
Rosa-Fontana AS, Dorigo AS, Malaquias JB, Pachú JKS, Nocelli RCF, Tosi S, Malaspina O. Fungivorous mites enhance the survivorship and development of stingless bees even when exposed to pesticides. Sci Rep 2022; 12:20948. [PMID: 36470975 PMCID: PMC9722777 DOI: 10.1038/s41598-022-25482-x] [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: 02/20/2022] [Accepted: 11/30/2022] [Indexed: 12/11/2022] Open
Abstract
Stingless bees are the largest group of eusocial bees in the world. They play an essential role as crop pollinators and have been considered for inclusion in pesticide risk assessments (RAs). Beyond the mutualism involving stingless bee larvae and fungi, the fungivorous mite Proctotydaeus (Neotydeolus) alvearii proved to be interesting for studies of associations with stingless bees. Their presence is related to colony strength and health, showing a permanent-host-association level. Here, we tested whether the coexistence with P. (N.) alvearii affects stingless bee larvae survivorship and development, including when fed pesticide-dosed food. We chose dimethoate, the reference standard for toxicity tests, and thiamethoxam, widely used in neotropical crops and listed to be reassessed in RAs. Bees associated with the mites showed higher larval survivorship rates, even in the dosed ones, and revealed changes in the developmental time and body size. Our study represents the first approach to stingless bee responses to the coexistence of fungivorous mites inside brood cells, leading us to believe that these mites play a beneficial role in stingless bees, including when they are exposed to pesticides.
Collapse
Affiliation(s)
- Annelise S. Rosa-Fontana
- grid.410543.70000 0001 2188 478XState University of Sao Paulo Júlio de Mesquita Filho, Rio Claro, SP Brazil
| | - Adna Suelen Dorigo
- grid.410543.70000 0001 2188 478XState University of Sao Paulo Júlio de Mesquita Filho, Rio Claro, SP Brazil
| | - José Bruno Malaquias
- grid.11899.380000 0004 1937 0722Escola Superior de Agricultura “Luiz de Queiroz”, University of Sao Paulo, Piracicaba, SP Brazil
| | - Jéssica K. S. Pachú
- grid.11899.380000 0004 1937 0722Escola Superior de Agricultura “Luiz de Queiroz”, University of Sao Paulo, Piracicaba, SP Brazil
| | - Roberta C. F. Nocelli
- grid.411247.50000 0001 2163 588XCentre of Agrarian Science, Federal University of Sao Carlos, Araras, SP Brazil ,grid.7605.40000 0001 2336 6580Department of Agricultural, Forest, and Food Sciences, University of Torino, Grugliasco, Italy
| | - Simone Tosi
- grid.7605.40000 0001 2336 6580Department of Agricultural, Forest, and Food Sciences, University of Torino, Grugliasco, Italy
| | - Osmar Malaspina
- grid.410543.70000 0001 2188 478XState University of Sao Paulo Júlio de Mesquita Filho, Rio Claro, SP Brazil
| |
Collapse
|
13
|
Doublet V, Doyle T, Refoy I, Hedges S, Carvell C, Brown MJF, Wilfert L. Increasing flower species richness in agricultural landscapes alters insect pollinator networks: Implications for bee health and competition. Ecol Evol 2022; 12:e9442. [PMID: 36311409 PMCID: PMC9608809 DOI: 10.1002/ece3.9442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/18/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022] Open
Abstract
Ecological restoration programs are established to reverse land degradation, mitigate biodiversity loss, and reinstate ecosystem services. Following recent agricultural intensification that led to a decrease in flower diversity and density in rural areas and subsequently to the decline of many insects, conservation measures targeted at pollinators have been established, including sown wildflower strips (WFS) along field margins. Historically successful in establishing a high density of generalist bees and increasing pollinator diversity, the impact of enhanced flower provision on wider ecological interactions and the structure of pollinator networks has been rarely investigated. Here, we tested the effects of increasing flower species richness and flower density in agricultural landscapes on bee‐plant interaction networks. We measured plant species richness and flower density and surveyed honeybee and bumblebee visits on flowers across a range of field margins on 10 UK farms that applied different pollinator conservation measures. We found that both flower species richness and flower density significantly increased bee abundance, in early and late summer, respectively. At the network level, we found that higher flower species richness did not significantly alter bee species' generality indices, but significantly reduced network connectance and marginally reduced niche overlap across honeybees and bumblebee species, a proxy for insect competition. While higher connectance and niche overlap is believed to strengthen network robustness and often is the aim for the restoration of pollinator networks, we argue that carefully designed WFS may benefit bees by partitioning their foraging niche, limiting competition for resources and the potential for disease transmission via shared floral use. We also discuss the need to extend WFS and their positive effects into spring when wild bee populations are established.
Collapse
Affiliation(s)
- Vincent Doublet
- College of Life and Environmental SciencesUniversity of ExeterPenrynUK,Institute of Evolutionary Ecology and Conservation GenomicsUniversity of UlmUlmGermany
| | - Toby Doyle
- College of Life and Environmental SciencesUniversity of ExeterPenrynUK
| | - Isobel Refoy
- College of Life and Environmental SciencesUniversity of ExeterPenrynUK
| | - Sophie Hedges
- College of Life and Environmental SciencesUniversity of ExeterPenrynUK,Department of Comparative Biomedical SciencesThe Royal Veterinary CollegeHatfieldUK
| | | | - Mark J. F. Brown
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Lena Wilfert
- College of Life and Environmental SciencesUniversity of ExeterPenrynUK,Institute of Evolutionary Ecology and Conservation GenomicsUniversity of UlmUlmGermany
| |
Collapse
|
14
|
Cilia G, Flaminio S, Zavatta L, Ranalli R, Quaranta M, Bortolotti L, Nanetti A. Occurrence of Honey Bee (Apis mellifera L.) Pathogens in Wild Pollinators in Northern Italy. Front Cell Infect Microbiol 2022; 12:907489. [PMID: 35846743 PMCID: PMC9280159 DOI: 10.3389/fcimb.2022.907489] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Diseases contribute to the decline of pollinator populations, which may be aggravated by the interspecific transmission of honey bee pests and pathogens. Flowers increase the risk of transmission, as they expose the pollinators to infections during the foraging activity. In this study, both the prevalence and abundance of 21 honey bee pathogens (11 viruses, 4 bacteria, 3 fungi, and 3 trypanosomatids) were assessed in the flower-visiting entomofauna sampled from March to September 2021 in seven sites in the two North-Italian regions, Emilia-Romagna and Piedmont. A total of 1,028 specimens were collected, identified, and analysed. Of the twenty-one pathogens that were searched for, only thirteen were detected. Altogether, the prevalence of the positive individuals reached 63.9%, with Nosema ceranae, deformed wing virus (DWV), and chronic bee paralysis virus (CBPV) as the most prevalent pathogens. In general, the pathogen abundance averaged 5.15 * 106 copies, with CBPV, N. ceranae, and black queen cell virus (BQCV) as the most abundant pathogens, with 8.63, 1.58, and 0.48 * 107 copies, respectively. All the detected viruses were found to be replicative. The sequence analysis indicated that the same genetic variant was circulating in a specific site or region, suggesting that interspecific transmission events among honey bees and wild pollinators are possible. Frequently, N. ceranae and DWV were found to co-infect the same individual. The circulation of honey bee pathogens in wild pollinators was never investigated before in Italy. Our study resulted in the unprecedented detection of 72 wild pollinator species as potential hosts of honey bee pathogens. Those results encourage the implementation of monitoring actions aiming to improve our understanding of the environmental implications of such interspecific transmission events, which is pivotal to embracing a One Health approach to pollinators’ welfare.
Collapse
|
15
|
Bartlett LJ. Frontiers in effective control of problem parasites in beekeeping. Int J Parasitol Parasites Wildl 2022; 17:263-272. [PMID: 35309040 PMCID: PMC8924282 DOI: 10.1016/j.ijppaw.2022.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/27/2022] [Accepted: 03/01/2022] [Indexed: 12/21/2022]
Abstract
Demand for better control of certain parasites in managed western honey bees (Apis mellifera L.) remains apparent amongst beekeepers in both Europe and North America, and is of widespread public, scientific, and agricultural concern. Academically, interest from numerous fields including veterinary sciences has led to many exemplary reviews of the parasites of honey bees and the treatment options available. However, summaries of current research frontiers in treating both novel and long-known parasites of managed honey bees are lacking. This review complements the currently comprehensive body of literature summarizing the effectiveness of parasite control in managed honey bees by outlining where significant gaps in development, implementation, and uptake lie, including integration into IPM frameworks and separation of cultural, biological, and chemical controls. In particular, I distinguish where challenges in identifying appropriate controls exist in the lab compared to where we encounter hurdles in technology transfer due to regulatory, economic, or cultural contexts. I overview how exciting frontiers in honey bee parasite control research are clearly demonstrated by the abundance of recent publications on novel control approaches, but also caution that temperance must be levied on the applied end of the research engine in believing that what can be achieved in a laboratory research environment can be quickly and effectively marketed for deployment in the field.
Collapse
Affiliation(s)
- Lewis J Bartlett
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, 30602, USA
| |
Collapse
|
16
|
Piot N, Smagghe G. Critical View on the Importance of Host Defense Strategies on Virus Distribution of Bee Viruses: What Can We Learn from SARS-CoV-2 Variants? Viruses 2022; 14:503. [PMID: 35336909 PMCID: PMC8951442 DOI: 10.3390/v14030503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/22/2022] [Accepted: 02/26/2022] [Indexed: 02/05/2023] Open
Abstract
Bees, both wild and domesticated ones, are hosts to a plethora of viruses, with most of them infecting a wide range of bee species and genera. Although viral discovery and research on bee viruses date back over 50 years, the last decade is marked by a surge of new studies, new virus discoveries, and reports on viral transmission in and between bee species. This steep increase in research on bee viruses was mainly initiated by the global reports on honeybee colony losses and the worldwide wild bee decline, where viruses are regarded as one of the main drivers. While the knowledge gained on bee viruses has significantly progressed in a short amount of time, we believe that integration of host defense strategies and their effect on viral dynamics in the multi-host viral landscape are important aspects that are currently still missing. With the large epidemiological dataset generated over the last two years on the SARS-CoV-2 pandemic, the role of these defense mechanisms in shaping viral dynamics has become eminent. Integration of these dynamics in a multi-host system would not only greatly aid the understanding of viral dynamics as a driver of wild bee decline, but we believe bee pollinators and their viruses provide an ideal system to study the multi-host viruses and their epidemiology.
Collapse
Affiliation(s)
- Niels Piot
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| |
Collapse
|
17
|
Tehel A, Streicher T, Tragust S, Paxton RJ. Experimental cross species transmission of a major viral pathogen in bees is predominantly from honeybees to bumblebees. Proc Biol Sci 2022; 289:20212255. [PMID: 35168401 PMCID: PMC8848241 DOI: 10.1098/rspb.2021.2255] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cross-species transmission of a pathogen from a reservoir to a recipient host species, spillover, can have major impacts on biodiversity, domestic species and human health. Deformed wing virus (DWV) is a panzootic RNA virus in honeybees that is causal in their elevated colony losses, and several correlative field studies have suggested spillover of DWV from managed honeybees to wild bee species such as bumblebees. Yet unequivocal demonstration of DWV spillover is lacking, while spillback, the transmission of DWV from a recipient back to the reservoir host, is rarely considered. Here, we show in fully crossed laboratory experiments that the transmission of DWV (genotype A) from honeybees to bumblebees occurs readily, yet we neither detected viral transmission from bumblebees to honeybees nor onward transmission from experimentally infected to uninoculated bumblebees. Our results support the potential for viral spillover from honeybees to other bee species in the field when robbing resources from heterospecific nests or when visiting the same flowers. They also underscore the importance of studies on the virulence of DWV in wild bee species so as to evaluate viral impact on individual and population fitness as well as viral adaption to new host species.
Collapse
Affiliation(s)
- Anja Tehel
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Tabea Streicher
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Simon Tragust
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Robert J. Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstrasse 4, 04103 Leipzig, Germany
| |
Collapse
|
18
|
Presence of Known and Emerging Honey Bee Pathogens in Apiaries of Veneto Region (Northeast of Italy) during Spring 2020 and 2021. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12042134] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A progressive honey bee population decline has been reported worldwide during the last decades, and it could be attributed to several causes, in particular to the presence of pathogens and parasites that can act individually or in synergy. The health status of nine apiaries located in different areas of the Veneto region (northeast of Italy) was assessed for two consecutive years (2020 and 2021) in spring, during the resumption of honey bee activity, for determining the presence of known (Nosema spp., Varroa mite and viruses) and less known or emerging pathogens (Lotmaria passim and Crithidia mellificae) in honey bees. After honey bees sampling from each of the nine apiaries, Nosema apis, Nosema ceranae, L. passim, C. mellificae, ABPV, CBPV, IAPV, KBV, BQCV, SBV, DWV-A, DWV-B and V. destructor were investigated either by microscopic observation or PCR protocols. The viruses BQCV, SBV, CBPV followed by N. ceranae and L. passim were the most prevalent pathogens, and many of the investigated hives, despite asymptomatic, had different degrees of co-infection. This study aimed to highlight, during the resumption of honey bee activity in spring, the prevalence and spreading in the regional territory of different honey bee pathogens, which could alone or synergistically alter the homeostasis of bees colonies. The information gathered would increase our knowledge about the presence of these microorganisms and parasites in the territory and could contribute to improve beekeepers practice.
Collapse
|
19
|
Honey bees and climate explain viral prevalence in wild bee communities on a continental scale. Sci Rep 2022; 12:1904. [PMID: 35115568 PMCID: PMC8814194 DOI: 10.1038/s41598-022-05603-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/23/2021] [Indexed: 01/10/2023] Open
Abstract
Viruses are omnipresent, yet the knowledge on drivers of viral prevalence in wild host populations is often limited. Biotic factors, such as sympatric managed host species, as well as abiotic factors, such as climatic variables, are likely to impact viral prevalence. Managed and wild bees, which harbor several multi-host viruses with a mostly fecal-oral between-species transmission route, provide an excellent system with which to test for the impact of biotic and abiotic factors on viral prevalence in wild host populations. Here we show on a continental scale that the prevalence of three broad host viruses: the AKI-complex (Acute bee paralysis virus, Kashmir bee virus and Israeli acute paralysis virus), Deformed wing virus, and Slow bee paralysis virus in wild bee populations (bumble bees and solitary bees) is positively related to viral prevalence of sympatric honey bees as well as being impacted by climatic variables. The former highlights the need for good beekeeping practices, including Varroa destructor management to reduce honey bee viral infection and hive placement. Furthermore, we found that viral prevalence in wild bees is at its lowest at the extreme ends of both temperature and precipitation ranges. Under predicted climate change, the frequency of extremes in precipitation and temperature will continue to increase and may hence impact viral prevalence in wild bee communities.
Collapse
|
20
|
de Miranda JR, Brettell LE, Chejanovsky N, Childers AK, Dalmon A, Deboutte W, de Graaf DC, Doublet V, Gebremedhn H, Genersch E, Gisder S, Granberg F, Haddad NJ, Kaden R, Manley R, Matthijnssens J, Meeus I, Migdadi H, Milbrath MO, Mondet F, Remnant EJ, Roberts JMK, Ryabov EV, Sela N, Smagghe G, Somanathan H, Wilfert L, Wright ON, Martin SJ, Ball BV. Cold case: The disappearance of Egypt bee virus, a fourth distinct master strain of deformed wing virus linked to honeybee mortality in 1970's Egypt. Virol J 2022; 19:12. [PMID: 35033134 PMCID: PMC8760790 DOI: 10.1186/s12985-022-01740-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 12/31/2021] [Indexed: 01/11/2023] Open
Abstract
In 1977, a sample of diseased adult honeybees (Apis mellifera) from Egypt was found to contain large amounts of a previously unknown virus, Egypt bee virus, which was subsequently shown to be serologically related to deformed wing virus (DWV). By sequencing the original isolate, we demonstrate that Egypt bee virus is in fact a fourth unique, major variant of DWV (DWV-D): more closely related to DWV-C than to either DWV-A or DWV-B. DWV-A and DWV-B are the most common DWV variants worldwide due to their close relationship and transmission by Varroa destructor. However, we could not find any trace of DWV-D in several hundred RNA sequencing libraries from a worldwide selection of honeybee, varroa and bumblebee samples. This means that DWV-D has either become extinct, been replaced by other DWV variants better adapted to varroa-mediated transmission, or persists only in a narrow geographic or host range, isolated from common bee and beekeeping trade routes.
Collapse
Affiliation(s)
- Joachim R de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, 750-07, Uppsala, Sweden.
| | - Laura E Brettell
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Renrith, NSW, 2751, Australia.,School of Environment and Life Sciences, University of Salford, Manchester, M5 4WT, UK.,Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Nor Chejanovsky
- Institute of Plant Protection, The Volcani Center, PO Box 15159, 7528809, Rishon Lezion, Israel
| | - Anna K Childers
- Bee Research Laboratory, Beltsville Agricultural Research Center, USDA, Beltsville, MD, 20705, USA
| | - Anne Dalmon
- Abeilles et Environnement, INRAE, 84914, Avignon, France
| | - Ward Deboutte
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, University of Leuven, 3000, Leuven, Belgium.,Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Dirk C de Graaf
- Laboratory of Molecular Entomology and Bee Pathology, Ghent University, 9000, Ghent, Belgium
| | - Vincent Doublet
- College of Life and Environmental Sciences, University of Exeter, Penryn, TR10 9FE, UK.,Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Haftom Gebremedhn
- Laboratory of Molecular Entomology and Bee Pathology, Ghent University, 9000, Ghent, Belgium.,Tigray Agricultural Research Institute, P.O. Box 492, Mekelle, Ethiopia
| | - Elke Genersch
- Institut Für Mikrobiologie Und Tierseuchen, Fachbereich Veterinärmedizin, Freie Universität Berlin, Berlin, Germany.,Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, Hohen Neuendorf, Germany
| | - Sebastian Gisder
- Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, Hohen Neuendorf, Germany
| | - Fredrik Granberg
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 750-07, Uppsala, Sweden
| | - Nizar J Haddad
- Bee Research Department, National Agricultural Research Center, Baq'a, Jordan
| | - Rene Kaden
- Department of Ecology, Swedish University of Agricultural Sciences, 750-07, Uppsala, Sweden.,Clinical Microbiology, Department of Medical Sciences, Uppsala University, 753 09, Uppsala, Sweden
| | - Robyn Manley
- College of Life and Environmental Sciences, University of Exeter, Penryn, TR10 9FE, UK
| | - Jelle Matthijnssens
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, University of Leuven, 3000, Leuven, Belgium
| | - Ivan Meeus
- Laboratory of Agrozoology, Department of Plants and Crops, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Hussein Migdadi
- Bee Research Department, National Agricultural Research Center, Baq'a, Jordan
| | - Meghan O Milbrath
- Department of Ecology, Swedish University of Agricultural Sciences, 750-07, Uppsala, Sweden
| | - Fanny Mondet
- Abeilles et Environnement, INRAE, 84914, Avignon, France
| | - Emily J Remnant
- Behaviour, Ecology and Evolution (BEE) Lab, School of Life and Environmental Sciences, The University of Sydney, Camperdown, 2006, Australia
| | - John M K Roberts
- Commonwealth Scientific and Industrial Research Organisation, Canberra, 2601, Australia
| | - Eugene V Ryabov
- Bee Research Laboratory, Beltsville Agricultural Research Center, USDA, Beltsville, MD, 20705, USA
| | - Noa Sela
- Institute of Plant Protection, The Volcani Center, PO Box 15159, 7528809, Rishon Lezion, Israel
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Hema Somanathan
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, 695551, India
| | - Lena Wilfert
- College of Life and Environmental Sciences, University of Exeter, Penryn, TR10 9FE, UK.,Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Owen N Wright
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QG, UK
| | - Stephen J Martin
- School of Environment and Life Sciences, University of Salford, Manchester, M5 4WT, UK.,Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Brenda V Ball
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| |
Collapse
|
21
|
Simone-Finstrom M, Strand MK, Tarpy DR, Rueppell O. Impact of Honey Bee Migratory Management on Pathogen Loads and Immune Gene Expression is Affected by Complex Interactions With Environment, Worker Life History, and Season. JOURNAL OF INSECT SCIENCE (ONLINE) 2022; 22:6523145. [PMID: 35137136 PMCID: PMC8825759 DOI: 10.1093/jisesa/ieab096] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 05/12/2023]
Abstract
The effects of honey bee management, such as intensive migratory beekeeping, are part of the ongoing debate concerning causes of colony health problems. Even though comparisons of disease and pathogen loads among differently managed colonies indicate some effects, the direct impact of migratory practices on honey bee pathogens is poorly understood. To test long- and short-term impacts of managed migration on pathogen loads and immunity, experimental honey bee colonies were maintained with or without migratory movement. Individuals that experienced migration as juveniles (e.g., larval and pupal development), as adults, or both were compared to control colonies that remained stationary and therefore did not experience migratory relocation. Samples at different ages and life-history stages (hive bees or foragers), taken at the beginning and end of the active season, were analyzed for pathogen loads and physiological markers of health. Bees exposed to migratory management during adulthood had increased levels of the AKI virus complex (Acute bee paralysis, Kashmir bee, and Israeli acute bee paralysis viruses) and decreased levels of antiviral gene expression (dicer-like). However, those in stationary management as adults had elevated gut parasites (i.e. trypanosomes). Effects of environment during juvenile development were more complex and interacted with life-history stage and season. Age at collection, life-history stage, and season all influenced numerous factors from viral load to immune gene expression. Although the factors that we examined are not independent, the results illuminate potential factors in both migratory and nonmigratory beekeeping that are likely to contribute to colony stress, and also indicate potential mitigation measures.
Collapse
Affiliation(s)
- Michael Simone-Finstrom
- USDA-ARS Honey Bee Breeding, Genetics and Physiology Research Laboratory, 1157 Ben Hur Road, Baton Rouge, LA 70820, USA
- Corresponding author, e-mail:
| | - Micheline K Strand
- Life Sciences Branch, U.S. Army Research Office, 800 Park Office Drive, Research Triangle Park, NC 27703, USA
| | - David R Tarpy
- Department of Entomology and Plant Pathology, North Carolina State University, 100 Derieux Place, Raleigh, NC 27695, USA
- The W.M. Keck Center for Behavioral Biology, North Carolina State University, 112 Derieux Place, Raleigh, NC 27695, USA
- Current address: Department of Applied Ecology, North Carolina State University, 100 Eugene Brooks Avenue, Raleigh, NC 27695, USA
| | - Olav Rueppell
- Department of Biological Sciences, University of Alberta, CW 405 Biological Sciences Building, Edmonton, AB, T6G 2E9, Canada
- Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, Greensboro, NC 27412, USA
| |
Collapse
|
22
|
Ray AM, Davis SL, Rasgon JL, Grozinger CM. Simulated vector transmission differentially influences dynamics of two viral variants of deformed wing virus in honey bees ( Apis mellifera). J Gen Virol 2021; 102. [PMID: 34816791 PMCID: PMC8742989 DOI: 10.1099/jgv.0.001687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Understanding how vectors alter the interactions between viruses and their hosts is a fundamental question in virology and disease ecology. In honey bees, transmission of deformed wing virus (DWV) by parasitic Varroa mites has been associated with elevated disease and host mortality, and Varroa transmission has been hypothesized to lead to increased viral titres or select for more virulent variants. Here, we mimicked Varroa transmission by serially passaging a mixed population of two DWV variants, A and B, by injection through in vitro reared honey bee pupae and tracking these viral populations through five passages. The DWV-A and DWV-B variant proportions shifted dynamically through passaging, with DWV-B outcompeting DWV-A after one passage, but levels of both variants becoming equivalent by Passage 5. Sequencing analysis revealed a dominant, recombinant DWV-B strain (DWV-A derived 5′ IRES region with the rest of the genome DWV-B), with low nucleotide diversity that decreased through passaging. DWV-A populations had higher nucleotide diversity compared to DWV-B, but this also decreased through passaging. Selection signatures were found across functional regions of the DWV-A and DWV-B genomes, including amino acid mutations in the putative capsid protein region. Simulated vector transmission differentially impacted two closely related viral variants which could influence viral interactions with the host, demonstrating surprising plasticity in vector-host-viral dynamics.
Collapse
Affiliation(s)
- Allyson M Ray
- Molecular, Cellular, and Integrative Biosciences Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA.,Department of Entomology, Center for Infectious Disease Dynamics, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Sheldon L Davis
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Jason L Rasgon
- Molecular, Cellular, and Integrative Biosciences Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA.,Department of Entomology, Center for Infectious Disease Dynamics, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Christina M Grozinger
- Molecular, Cellular, and Integrative Biosciences Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA.,Department of Entomology, Center for Infectious Disease Dynamics, Center for Pollinator Research, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
23
|
Mráz P, Hýbl M, Kopecký M, Bohatá A, Hoštičková I, Šipoš J, Vočadlová K, Čurn V. Screening of Honey Bee Pathogens in the Czech Republic and Their Prevalence in Various Habitats. INSECTS 2021; 12:insects12121051. [PMID: 34940139 PMCID: PMC8706798 DOI: 10.3390/insects12121051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 01/04/2023]
Abstract
Western honey bee (Apis mellifera) is one of the most important pollinators in the world. Thus, a recent honey bee health decline and frequent honey bee mass losses have drawn attention and concern. Honey bee fitness is primarily reduced by pathogens, parasites, and viral load, exposure to pesticides and their residues, and inadequate nutrition from both the quality and amount of food resources. This study evaluated the prevalence of the most common honey bee pathogens and viruses in different habitats across the Czech Republic. The agroecosystems, urban ecosystems, and national park were chosen for sampling from 250 colonies in 50 apiaries. Surprisingly, the most prevalent honey bee pathogens belong to the family Trypanosomatidae including Lotmaria passim and Crithidia mellificae. As expected, the most prevalent viruses were DWV, followed by ABPV. Additionally, the occurrence of DWV-B and DWV-C were correlated with honey bee colony mortality. From the habitat point of view, most pathogens occurred in the town habitat, less in the agroecosystem and least in the national park. The opposite trend was observed in the occurrence of viruses. However, the prevalence of viruses was not affected by habitat.
Collapse
Affiliation(s)
- Petr Mráz
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
- Correspondence:
| | - Marian Hýbl
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| | - Marek Kopecký
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| | - Andrea Bohatá
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| | - Irena Hoštičková
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| | - Jan Šipoš
- Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic;
| | - Kateřina Vočadlová
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| | - Vladislav Čurn
- Faculty of Agriculture, University of South Bohemia in Ceske Budejovice, Studentska 1668, 370 05 Ceske Budejovice, Czech Republic; (M.H.); (M.K.); (A.B.); (I.H.); (K.V.); (V.Č.)
| |
Collapse
|
24
|
Wilfert L. Viral adaptations to vector-borne transmission can result in complex host-vector-pathogen interactions. J Anim Ecol 2021; 90:2230-2233. [PMID: 34609752 DOI: 10.1111/1365-2656.13570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/20/2021] [Indexed: 01/04/2023]
Abstract
Research Highlight: Norton, A. M., Remnant, E. J., Tom, J., Buchmann, G., Blacquiere, T., & Beekman, M. (2021). Adaptation to vector-based transmission in a honeybee virus. Journal of Animal Ecology, 90, https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2656.13493. In their paper on the adaptation to vector-based transmission via the mite Varroa destructor in a honeybee virus, Norton et al. study how high versus low levels of a viral vector affect viral load and potential competition between two strains of Deformed Wing Virus, an important highly virulent bee virus with the potential to spill-over into other pollinators and bee-associated insect species. This paper addresses two very timely issues, on the one hand on viral evolutionary ecology in response to vector-borne transmission, and on the other hand providing much needed information on an important honey bee pathogen. Using a complex natural system, this study shows that vector-borne transmission, and the control of the vector, can select for complex host-pathogen-vector interactions and that adaptations to changing transmission landscapes in fast evolving pathogens can create conditions for emerging pathogens to transition to endemic diseases.
Collapse
Affiliation(s)
- Lena Wilfert
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| |
Collapse
|
25
|
Nanetti A, Bortolotti L, Cilia G. Pathogens Spillover from Honey Bees to Other Arthropods. Pathogens 2021; 10:1044. [PMID: 34451508 PMCID: PMC8400633 DOI: 10.3390/pathogens10081044] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Honey bees, and pollinators in general, play a major role in the health of ecosystems. There is a consensus about the steady decrease in pollinator populations, which raises global ecological concern. Several drivers are implicated in this threat. Among them, honey bee pathogens are transmitted to other arthropods populations, including wild and managed pollinators. The western honey bee, Apis mellifera, is quasi-globally spread. This successful species acted as and, in some cases, became a maintenance host for pathogens. This systematic review collects and summarizes spillover cases having in common Apis mellifera as the mainteinance host and some of its pathogens. The reports are grouped by final host species and condition, year, and geographic area of detection and the co-occurrence in the same host. A total of eighty-one articles in the time frame 1960-2021 were included. The reported spillover cases cover a wide range of hymenopteran host species, generally living in close contact with or sharing the same environmental resources as the honey bees. They also involve non-hymenopteran arthropods, like spiders and roaches, which are either likely or unlikely to live in close proximity to honey bees. Specific studies should consider host-dependent pathogen modifications and effects on involved host species. Both the plasticity of bee pathogens and the ecological consequences of spillover suggest a holistic approach to bee health and the implementation of a One Health approach.
Collapse
Affiliation(s)
| | - Laura Bortolotti
- Council for Agricultural Research and Agricultural Economics Analysis, Centre for Agriculture and Environment Research (CREA-AA), Via di Saliceto 80, 40128 Bologna, Italy; (A.N.); (G.C.)
| | | |
Collapse
|
26
|
Burnham PA, Alger SA, Case B, Boncristiani H, Hébert‐Dufresne L, Brody AK. Flowers as dirty doorknobs: Deformed wing virus transmitted between
Apis mellifera
and
Bombus impatiens
through shared flowers. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13962] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Phillip Alexander Burnham
- Department of Biology University of Vermont Burlington VT USA
- Vermont Complex Systems Center University of Vermont Burlington VT USA
| | - Samantha A. Alger
- Plant and Soil Science University of Vermont Burlington VT USA
- Vanasse Hangen Brustlin, Inc South Burlington VT USA
| | - Brendan Case
- Vermont Complex Systems Center University of Vermont Burlington VT USA
- Computer Science Department University of Vermont Burlington VT USA
| | - Humberto Boncristiani
- Honeybee Research and Extension Laboratory Entomology and Nematology Department University of Florida Gainesville FL USA
| | - Laurent Hébert‐Dufresne
- Vermont Complex Systems Center University of Vermont Burlington VT USA
- Computer Science Department University of Vermont Burlington VT USA
| | - Alison K. Brody
- Department of Biology University of Vermont Burlington VT USA
| |
Collapse
|
27
|
|
28
|
The First Detection and Genetic Characterization of Four Different Honeybee Viruses in Wild Bumblebees from Croatia. Pathogens 2021; 10:pathogens10070808. [PMID: 34202101 PMCID: PMC8308666 DOI: 10.3390/pathogens10070808] [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: 05/29/2021] [Revised: 06/18/2021] [Accepted: 06/24/2021] [Indexed: 11/17/2022] Open
Abstract
To determine the presence and the prevalence of four different honeybee viruses (acute bee paralysis virus—ABPV, black queen cell virus—BQCV, chronic bee paralysis virus—CBPV, deformed wing virus—DWV) in wild bumblebees, pooled randomly selected bumblebee samples were collected from twenty-seven different locations in the territory of Croatia. All samples were prepared and examined using the RT-PCR methods for quantification of mentioned honeybee viruses. Determined prevalence (%) of identified positive viruses were in the following decreasing order: BQCV > DWV > ABPV, CBPV. Additionally, direct sequencing of samples positive for BQCV (n = 24) and DWV (n = 2) was performed, as well as a test of molecular phylogeny comparison with those available in GenBank. Selected positive field viruses’ strains showed 95.7 to 100% (BQCV) and 98.09% (DWV) nucleotide identity with previously detected and deposited honeybee virus strains in the geographic areas in Croatia and neighboring Slovenia. In this article, the first detection of four honeybee viruses with genetic characterization of high diversity strains circulating in wild bumblebees in Croatia is presented.
Collapse
|
29
|
Cilia G, Zavatta L, Ranalli R, Nanetti A, Bortolotti L. Replicative Deformed Wing Virus Found in the Head of Adults from Symptomatic Commercial Bumblebee ( Bombus terrestris) Colonies. Vet Sci 2021; 8:117. [PMID: 34201628 PMCID: PMC8310072 DOI: 10.3390/vetsci8070117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 02/05/2023] Open
Abstract
The deformed wing virus (DWV) is one of the most common honey bee pathogens. The virus may also be detected in other insect species, including Bombus terrestris adults from wild and managed colonies. In this study, individuals of all stages, castes, and sexes were sampled from three commercial colonies exhibiting the presence of deformed workers and analysed for the presence of DWV. Adults (deformed individuals, gynes, workers, males) had their head exscinded from the rest of the body and the two parts were analysed separately by RT-PCR. Juvenile stages (pupae, larvae, and eggs) were analysed undissected. All individuals tested positive for replicative DWV, but deformed adults showed a higher number of copies compared to asymptomatic individuals. Moreover, they showed viral infection in their heads. Sequence analysis indicated that the obtained DWV amplicons belonged to a strain isolated in the United Kingdom. Further studies are needed to characterize the specific DWV target organs in the bumblebees. The result of this study indicates the evidence of DWV infection in B. terrestris specimens that could cause wing deformities, suggesting a relationship between the deformities and the virus localization in the head. Further studies are needed to define if a specific organ could be a target in symptomatic bumblebees.
Collapse
Affiliation(s)
| | | | | | - Antonio Nanetti
- CREA Research Centre for Agriculture and Environment, Via di Saliceto 80, 40128 Bologna, Italy; (G.C.); (L.Z.); (R.R.); (L.B.)
| | | |
Collapse
|
30
|
Grindrod I, Kevill JL, Villalobos EM, Schroeder DC, Martin SJ. Ten Years of Deformed Wing Virus (DWV) in Hawaiian Honey Bees ( Apis mellifera), the Dominant DWV-A Variant Is Potentially Being Replaced by Variants with a DWV-B Coding Sequence. Viruses 2021; 13:969. [PMID: 34073733 PMCID: PMC8225128 DOI: 10.3390/v13060969] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022] Open
Abstract
The combination of Deformed wing virus (DWV) and Varroa destructor is arguably one of the greatest threats currently facing western honey bees, Apis mellifera. Varroa's association with DWV has decreased viral diversity and increased loads of DWV within honey bee populations. Nowhere has this been better studied than in Hawaii, where the arrival of Varroa progressively led to the dominance of the single master variant (DWV-A) on both mite-infested Hawaiian Islands of Oahu and Big Island. Now, exactly 10 years following the original study, we find that the DWV population has changed once again, with variants containing the RdRp coding sequence pertaining to the master variant B beginning to co-dominate alongside variants with the DWV-A RdRp sequence on the mite-infested islands of Oahu and Big Island. In speculation, based on other studies, it appears this could represent a stage in the journey towards the complete dominance of DWV-B, a variant that appears better adapted to be transmitted within honey bee colonies.
Collapse
Affiliation(s)
- Isobel Grindrod
- School of Environment and Life Sciences, University of Salford, Manchester M5 4WX, UK;
| | - Jessica L. Kevill
- Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA;
- School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK;
| | - Ethel M. Villalobos
- College of Tropical Agriculture and Human Resources, University of Hawaii at Mānoa, 3050 Maile Way, Honolulu, HI 96822, USA;
| | - Declan C. Schroeder
- School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK;
- Environmental Biology (Virology), School of Biological Sciences, University of Reading, Reading RG6 6AH, UK
| | - Stephen John Martin
- School of Environment and Life Sciences, University of Salford, Manchester M5 4WX, UK;
| |
Collapse
|
31
|
Pascall DJ, Tinsley MC, Clark BL, Obbard DJ, Wilfert L. Virus Prevalence and Genetic Diversity Across a Wild Bumblebee Community. Front Microbiol 2021; 12:650747. [PMID: 33967987 PMCID: PMC8100031 DOI: 10.3389/fmicb.2021.650747] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/24/2021] [Indexed: 12/16/2022] Open
Abstract
Viruses are key population regulators, but we have limited knowledge of the diversity and ecology of viruses. This is even the case in wild host populations that provide ecosystem services, where small fitness effects may have major ecological impacts in aggregate. One such group of hosts are the bumblebees, which have a major role in the pollination of food crops and have suffered population declines and range contractions in recent decades. In this study, we investigate the diversity of four recently discovered bumblebee viruses (Mayfield virus 1, Mayfield virus 2, River Liunaeg virus, and Loch Morlich virus), and two previously known viruses that infect both wild bumblebees and managed honeybees (Acute bee paralysis virus and Slow bee paralysis virus) from isolates in Scotland. We investigate the ecological and environmental factors that determine viral presence and absence. We show that the recently discovered bumblebee viruses were more genetically diverse than the viruses shared with honeybees. Coinfection is potentially important in shaping prevalence: we found a strong positive association between River Liunaeg virus and Loch Morlich virus presence after controlling for host species, location and other relevant ecological variables. We tested for a relationship between environmental variables (temperature, UV radiation, wind speed, and prevalence), but as we had few sampling sites, and thus low power for site-level analyses, we could not conclude anything regarding these variables. We also describe the relationship between the bumblebee communities at our sampling sites. This study represents a first step in the description of predictors of bumblebee infection in the wild.
Collapse
Affiliation(s)
- David J. Pascall
- Institute of Biodiversity, Animal Health and Comparative Medicine, Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow, Glasgow, United Kingdom
- Centre for Ecology and Conservation, University of Exeter, Cornwall, United Kingdom
| | - Matthew C. Tinsley
- Biological and Environmental Sciences, University of Stirling, Stirling, United Kingdom
| | - Bethany L. Clark
- BirdLife International, The David Attenborough Building, Cambridge, United Kingdom
- Environment and Sustainability Institute, University of Exeter, Cornwall, United Kingdom
| | - Darren J. Obbard
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Lena Wilfert
- Centre for Ecology and Conservation, University of Exeter, Cornwall, United Kingdom
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
| |
Collapse
|
32
|
Norton AM, Remnant EJ, Tom J, Buchmann G, Blacquiere T, Beekman M. Adaptation to vector-based transmission in a honeybee virus. J Anim Ecol 2021; 90:2254-2267. [PMID: 33844844 DOI: 10.1111/1365-2656.13493] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 04/06/2021] [Indexed: 11/27/2022]
Abstract
Global pollinator declines as a result of emerging infectious diseases are of major concern. Managed honeybees Apis mellifera are susceptible to numerous parasites and pathogens, many of which appear to be transmissible to sympatric non-Apis taxa. The ectoparasitic mite Varroa destructor is considered to be the most significant threat to honeybees due to its role in vectoring RNA viruses, particularly Deformed wing virus (DWV). Vector transmission of DWV has resulted in the accumulation of high viral loads in honeybees and is often associated with colony death. DWV has two main genotypes, A and B. DWV-A was more prevalent during the initial phase of V. destructor establishment. In recent years, the global prevalence of DWV-B has increased, suggesting that DWV-B is better adapted to vector transmission than DWV-A. We aimed to determine the role vector transmission plays in DWV genotype prevalence at a colony level. We experimentally increased or decreased the number of V. destructor mites in honeybee colonies, and tracked DWV-A and DWV-B loads over a period of 10 months. Our results show that the two DWV genotypes differ in their response to mite numbers. DWV-A accumulation in honeybees was positively correlated with mite numbers yet DWV-A was largely undetected in the absence of the mite. In contrast, colonies had high loads of DWV-B even when mite numbers were low. DWV-B loads persisted in miticide-treated colonies, indicating that this genotype has a competitive advantage over DWV-A irrespective of mite numbers. Our findings suggest that the global increase in DWV-B prevalence is not driven by selective pressure by the vector. Rather, DWV-B is able to persist in colonies at higher viral loads relative to DWV-A in the presence and absence of V. destructor. The interplay between V. destructor and DWV genotypes within honeybee colonies may have broad consequences upon viral diversity in sympatric taxa as a result of spillover.
Collapse
Affiliation(s)
- Amanda M Norton
- Behaviour, Ecology and Evolution (BEE) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Emily J Remnant
- Behaviour, Ecology and Evolution (BEE) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Jolanda Tom
- Wageningen University and Research, Wageningen, The Netherlands
| | - Gabriele Buchmann
- Behaviour, Ecology and Evolution (BEE) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | | | - Madeleine Beekman
- Behaviour, Ecology and Evolution (BEE) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.,Wissenschaftskolleg zu Berlin, Berlin, Germany
| |
Collapse
|
33
|
Dalmon A, Diévart V, Thomasson M, Fouque R, Vaissière BE, Guilbaud L, Le Conte Y, Henry M. Possible Spillover of Pathogens between Bee Communities Foraging on the Same Floral Resource. INSECTS 2021; 12:insects12020122. [PMID: 33573084 PMCID: PMC7911050 DOI: 10.3390/insects12020122] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 01/02/2023]
Abstract
Simple Summary Floral resource availability is one of the keys to preserving the health of bee communities. However, flowers also present a risk of pathogen transmission, as infected pollinators could deposit pathogens while foraging, exposing other pollinators to infection via the consumption of contaminated nectar or pollen. Here, we studied, over time, the prevalence of seven viruses in bee communities that share the same small surface of floral resource in order to assess the risk of virus spillover. In total, 2057 bee specimens from 30 species were caught, identified and checked for the presence of viruses. Specimens from the Halictidae family were the dominant wild bees. The prevalence of viruses was quite high: at least one virus was detected in 78% of the samples, and co-infections were frequent. The genetic diversity of the viruses was also investigated to look for the possible association of geographic origin or host with shared ancestry. Abstract Viruses are known to contribute to bee population decline. Possible spillover is suspected from the co-occurrence of viruses in wild bees and honey bees. In order to study the risk of virus transmission between wild and managed bee species sharing the same floral resource, we tried to maximize the possible cross-infections using Phacelia tanacetifolia, which is highly attractive to honey bees and a broad range of wild bee species. Virus prevalence was compared over two years in Southern France. A total of 1137 wild bees from 29 wild bee species (based on COI barcoding) and 920 honey bees (Apis mellifera) were checked for the seven most common honey bee RNA viruses. Halictid bees were the most abundant. Co-infections were frequent, and Sacbrood virus (SBV), Black queen cell virus (BQCV), Acute bee paralysis virus (ABPV) and Israeli acute paralysis virus (IAPV) were widespread in the hymenopteran pollinator community. Conversely, Deformed wing virus (DWV) was detected at low levels in wild bees, whereas it was highly prevalent in honey bees (78.3% of the samples). Both wild bee and honey bee virus isolates were sequenced to look for possible host-specificity or geographical structuring. ABPV phylogeny suggested a specific cluster for Eucera bees, while isolates of DWV from bumble bees (Bombus spp.) clustered together with honey bee isolates, suggesting a possible spillover.
Collapse
|
34
|
Occurrence of bee viruses and pathogens associated with emerging infectious diseases in native and non-native bumble bees in southern Chile. Biol Invasions 2021. [DOI: 10.1007/s10530-020-02428-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
35
|
Brettell LE, Schroeder DC, Martin SJ. RNAseq of Deformed Wing Virus and Other Honey Bee-Associated Viruses in Eight Insect Taxa with or without Varroa Infestation. Viruses 2020; 12:E1229. [PMID: 33138298 PMCID: PMC7692275 DOI: 10.3390/v12111229] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
The global spread of a parasitic mite (Varroa destructor) has resulted in Deformed wing virus (DWV), a previously rare pathogen, now dominating the viromes in honey bees and contributing to large-scale honey bee colony losses. DWV can be found in diverse insect taxa and has been implicated in spilling over from honey bees into associated ("apiary") and other ("non-apiary") insects. Here we generated next generation sequence data from 127 insect samples belonging to diverse taxa collected from Hawaiian islands with and without Varroa to identify whether the mite has indirectly affected the viral landscapes of key insect taxa across bees, wasps, flies and ants. Our data showed that, while Varroa was associated with a dramatic increase in abundance of (predominantly recombinant) DWV in honey bees (and no other honey bee-associated RNA virus), this change was not seen in any other taxa sampled. Honey bees share their environment with other insect populations and exist as a homogenous group, frequently sharing common viruses, albeit at low levels. Our data suggest that the threat of Varroa to increase viral load in an apiary does not automatically translate to an increase in virus load in other insects living in the wider community.
Collapse
Affiliation(s)
- Laura E. Brettell
- Hawkesbury Institute for the Environment, Western Sydney University, Locked bag 1797, Penrith, NSW 2751, Australia
- School of Environment and life Sciences, University of Salford, Manchester M5 5WT, UK;
| | - Declan C. Schroeder
- Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St Paul, MN 55108, USA;
- School of Biological Sciences, University of Reading, Reading RG6 6LA, UK
| | - Stephen J. Martin
- School of Environment and life Sciences, University of Salford, Manchester M5 5WT, UK;
| |
Collapse
|
36
|
Evidence for and against deformed wing virus spillover from honey bees to bumble bees: a reverse genetic analysis. Sci Rep 2020; 10:16847. [PMID: 33033296 PMCID: PMC7546617 DOI: 10.1038/s41598-020-73809-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 09/22/2020] [Indexed: 01/05/2023] Open
Abstract
Deformed wing virus (DWV) is a persistent pathogen of European honey bees and the major contributor to overwintering colony losses. The prevalence of DWV in honey bees has led to significant concerns about spillover of the virus to other pollinating species. Bumble bees are both a major group of wild and commercially-reared pollinators. Several studies have reported pathogen spillover of DWV from honey bees to bumble bees, but evidence of a sustained viral infection characterized by virus replication and accumulation has yet to be demonstrated. Here we investigate the infectivity and transmission of DWV in bumble bees using the buff-tailed bumble bee Bombus terrestris as a model. We apply a reverse genetics approach combined with controlled laboratory conditions to detect and monitor DWV infection. A novel reverse genetics system for three representative DWV variants, including the two master variants of DWV—type A and B—was used. Our results directly confirm DWV replication in bumble bees but also demonstrate striking resistance to infection by certain transmission routes. Bumble bees may support DWV replication but it is not clear how infection could occur under natural environmental conditions.
Collapse
|
37
|
Tehel A, Streicher T, Tragust S, Paxton RJ. Experimental infection of bumblebees with honeybee-associated viruses: no direct fitness costs but potential future threats to novel wild bee hosts. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200480. [PMID: 32874644 PMCID: PMC7428241 DOI: 10.1098/rsos.200480] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/10/2020] [Indexed: 05/05/2023]
Abstract
Pathogen spillover represents an important cause of biodiversity decline. For wild bee species such as bumblebees, many of which are in decline, correlational data point towards viral spillover from managed honeybees as a potential cause. Yet, impacts of these viruses on wild bees are rarely evaluated. Here, in a series of highly controlled laboratory infection assays with well-characterized viral inocula, we show that three viral types isolated from honeybees (deformed wing virus genotype A, deformed wing virus genotype B and black queen cell virus) readily replicate within hosts of the bumblebee Bombus terrestris. Impacts of these honeybee-derived viruses - either injected or fed - on the mortality of B. terrestris workers were, however, negligible and probably dependent on host condition. Our results highlight the potential threat of viral spillover from honeybees to novel wild bee species, though they also underscore the importance of additional studies on this and other wild bee species under field-realistic conditions to evaluate whether pathogen spillover has a negative impact on wild bee individuals and population fitness.
Collapse
Affiliation(s)
- Anja Tehel
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Tabea Streicher
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Simon Tragust
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Robert J. Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| |
Collapse
|
38
|
Norton AM, Remnant EJ, Buchmann G, Beekman M. Accumulation and Competition Amongst Deformed Wing Virus Genotypes in Naïve Australian Honeybees Provides Insight Into the Increasing Global Prevalence of Genotype B. Front Microbiol 2020; 11:620. [PMID: 32328051 PMCID: PMC7160646 DOI: 10.3389/fmicb.2020.00620] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/19/2020] [Indexed: 12/27/2022] Open
Abstract
Honeybee colony deaths are often attributed to the ectoparasitic mite Varroa destructor and deformed wing virus (DWV), vectored by the mite. In the presence of V. destructor both main genotypes (DWV-A and DWV-B) have been correlated with colony loss. Studies show that DWV-B is the most prevalent genotype in the United Kingdom and Europe. More recently DWV-B has increased in prevalence in the United States. The increasing prevalence of DWV-B at the expense of DWV-A suggests that competition exists between the genotypes. Competition may be due to disparities in virulence between genotypes, differences in fitness, such as rate of replication, or a combination of factors. In this study we investigated if DWV genotypes differ in their rate of accumulation in Australian honeybees naïve to both V. destructor and DWV, and if viral load was associated with mortality in honeybee pupae. We singly and co-infected pupae with DWV-A, DWV-B, and a recombinant strain isolated from a V. destructor tolerant bee population. We monitored viral accumulation throughout pupation, up to 192 h post-injection. We found significant differences in accumulation, where DWV-A accumulated to significantly lower loads than DWV-B and the DWV-recombinant. We also found evidence of competition, where DWV-B loads were significantly reduced in the presence of DWV-A, but still accumulated to the highest loads overall. In contrast to previous studies, we found significant differences in virulence between pupae injected with DWV-A and DWV-B. The average mortality associated with DWV-B (0.4% ± 0.33 SE) and DWV-recombinant (2.2% ± 0.83 SE) injection were significantly less than observed for DWV-A (11% ± 1.2 SE). Our results suggest that a higher proportion of DWV-B infected pupae will emerge into adults, compared to DWV-A. Overall, our data suggest that low mortality in pupae and the ability of DWV-B to accumulate to higher loads relative to DWV-A even during co-infection may favor vector transmission by V. destructor, and may thus be contributing factors to the increasing prevalence of DWV-B globally.
Collapse
Affiliation(s)
- Amanda M. Norton
- Behaviour, Ecology and Evolution (BEE) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | | | | | | |
Collapse
|
39
|
Manley R, Temperton B, Boots M, Wilfert L. Contrasting impacts of a novel specialist vector on multihost viral pathogen epidemiology in wild and managed bees. Mol Ecol 2020; 29:380-393. [PMID: 31834965 PMCID: PMC7003859 DOI: 10.1111/mec.15333] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 01/27/2023]
Abstract
Typically, pathogens infect multiple host species. Such multihost pathogens can show considerable variation in their degree of infection and transmission specificity, which has important implications for potential disease emergence. Transmission of multihost pathogens can be driven by key host species and changes in such transmission networks can lead to disease emergence. We study two viruses that show contrasting patterns of prevalence and specificity in managed honeybees and wild bumblebees, black queen cell virus (BQCV) and slow bee paralysis virus (SBPV), in the context of the novel transmission route provided by the virus‐vectoring Varroa destructor. Our key result is that viral communities and RNA virus genetic variation are structured by location, not host species or V. destructor presence. Interspecific transmission is pervasive with the same viral variants circulating between pollinator hosts in each location; yet, we found virus‐specific host differences in prevalence and viral load. Importantly, V. destructor presence increases the prevalence in honeybees and, indirectly, in wild bumblebees, but in contrast to its impact on deformed wing virus (DWV), BQCV and SBPV viral loads are not increased by Varroa presence, and do not show genetic evidence of recent emergence. Effective control of Varroa in managed honeybee colonies is necessary to mitigate further disease emergence, and alleviate disease pressure on our vital wild bee populations. More generally, our results highlight the over‐riding importance of geographical location to the epidemiological outcome despite the complexity of multihost‐parasite interactions.
Collapse
Affiliation(s)
- Robyn Manley
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK.,Department of Biosciences, University of Exeter, Exeter, UK
| | - Ben Temperton
- Department of Biosciences, University of Exeter, Exeter, UK
| | - Mike Boots
- Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Lena Wilfert
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK.,Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| |
Collapse
|
40
|
Schläppi D, Lattrell P, Yañez O, Chejanovsky N, Neumann P. Foodborne Transmission of Deformed Wing Virus to Ants ( Myrmica rubra). INSECTS 2019; 10:E394. [PMID: 31703426 PMCID: PMC6920936 DOI: 10.3390/insects10110394] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/28/2019] [Accepted: 11/05/2019] [Indexed: 11/17/2022]
Abstract
Virus host shifts occur frequently, but the whole range of host species and the actual transmission pathways are often poorly understood. Deformed wing virus (DWV), an RNA virus described from honeybees (Apis mellifera), has been shown to have a broad host range. Since ants are often scavenging on dead honeybees, foodborne transmission of these viruses may occur. However, the role of the ant Myrmica rubra as an alternative host is not known and foodborne transmission to ants has not been experimentally addressed yet. Here, we show with a 16-week feeding experiment that foodborne transmission enables DWV type-A and -B to infect M. rubra and that these ants may serve as a virus reservoir. However, the titers of both plus- and minus-sense viral RNA strands decreased over time. Since the ants were fed with highly virus-saturated honeybee pupae, this probably resulted in initial viral peaks, then approaching lower equilibrium titers in infected individuals later. Since DWV infections were also found in untreated field-collected M. rubra colonies, our results support the wide host range of DWV and further suggest foodborne transmission as a so far underestimated spread mechanism.
Collapse
Affiliation(s)
- Daniel Schläppi
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3097 Bern, Switzerland; (P.L.); (O.Y.); (N.C.); (P.N.)
| | - Patrick Lattrell
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3097 Bern, Switzerland; (P.L.); (O.Y.); (N.C.); (P.N.)
| | - Orlando Yañez
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3097 Bern, Switzerland; (P.L.); (O.Y.); (N.C.); (P.N.)
| | - Nor Chejanovsky
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3097 Bern, Switzerland; (P.L.); (O.Y.); (N.C.); (P.N.)
- Department of Entomology, Agricultural Research Organization, the Volcani Center, Bet Dagan 50250, Israel
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3097 Bern, Switzerland; (P.L.); (O.Y.); (N.C.); (P.N.)
- Swiss Bee Research Centre, Agroscope, 3097 Bern, Switzerland
| |
Collapse
|
41
|
Prevalence and population genetics of the emerging honey bee pathogen DWV in Chinese apiculture. Sci Rep 2019; 9:12042. [PMID: 31427723 PMCID: PMC6700284 DOI: 10.1038/s41598-019-48618-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 08/08/2019] [Indexed: 01/16/2023] Open
Abstract
Honey bees are agriculturally important, both as pollinators and by providing products such as honey. The sustainability of beekeeping is at risk through factors of global change such as habitat loss, as well as through the spread of infectious diseases. In China and other parts of Asia, beekeepers rely both on native Apis cerana and non-native Apis mellifera, putting bee populations at particular risk of disease emergence from multi-host pathogens. Indeed, two important honey bee parasites have emerged from East Asian honey bees, the mite Varroa destructor and the microsporidian Nosema ceranae. As V. destructor vectors viral bee diseases, we investigated whether another key bee pathogen, Deformed Wing Virus (DWV), may also have originated in East Asian honey bee populations. We use a large-scale survey of apiaries across China to investigate the prevalence and seasonality of DWV in managed A. mellifera and A. cerana colonies, showing that DWV-A prevalence was higher in A. mellifera, with a seasonal spike in prevalence in autumn and winter. Using phylogenetic and population genetic approaches, we show that while China and East Asian DWV isolates show comparatively high levels of genetic diversity, these bee populations are not a source for the current global DWV epidemic.
Collapse
|