The ectoparasitic mite Tropilaelaps mercedesae reduces western honey bee, Apismellifera, longevity and emergence weight, and promotes Deformed wing virus infections

ABSTRACTHoney bee (Apis mellifera) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic miteVarroa destructor, honey bee viruses that are often closely associated with the mite, and pesticides used to control the mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, mite-infested pupae, their associatedVarroamites, and uninfested pupae, comparing these to similar samples from untreated control colonies. Titers of DWV increased initially with the onset of the acaricide application and then slightly decreased progressively coinciding with the removal of theVarroamite infestation. This initial increase in DWV titers suggests a physiological effect of tau-fluvalinate on the host's susceptibility to viral infection. DWV titers in adult bees and uninfested pupae remained higher in treated colonies than in untreated colonies. The titers of SBV and BQCV did not show any direct relationship with mite infestation and showed a variety of possible effects of the acaricide treatment. The results indicate that other factors besidesVarroamite infestation may be important to the development and maintenance of damaging DWV titers in colonies. Possible biochemical explanations for the observed synergistic effects between tau-fluvalinate and virus infections are discussed.

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Honey bee suppresses the parasitic mite Vitellogenin by antimicrobial peptide

10.1101/2020.02.29.970913 ◽

2020 ◽

Author(s):

Yunfei Wu ◽

Qiushi Liu ◽

Benjamin Weiss ◽

Martin Kaltenpoth ◽

Tatsuhiko Kadowaki

Keyword(s):

Viral Replication ◽

Honey Bee ◽

Fruit Fly ◽

Mite Infestation ◽

Negative Effects ◽

Deformed Wing Virus ◽

Active Viral Replication ◽

Tropilaelaps Mercedesae ◽

Parasitic Mite ◽

Physiological Outcomes

AbstractThe negative effects of honey bee parasitic mites and deformed wing virus (DWV) on honey bee and colony health have been well characterized. However, the relationship between DWV and mites, particularly viral replication inside the mites, remains unclear. Furthermore, the physiological outcomes of honey bee immune responses stimulated by DWV and the mite to the host (honey bee) and perhaps the pathogen/parasite (DWV/mite) are not yet understood. To answer these questions, we studied the tripartite interactions between the honey bee, Tropilaelaps mercedesae, and DWV as the model. T. mercedesae functioned as a vector for DWV without supporting active viral replication. Thus, DWV negligibly affected mite fitness. Mite infestation induced mRNA expression of antimicrobial peptides (AMPs), Defensin-1 and Hymenoptaecin, which correlated with DWV copy number in honey bee pupae and mite feeding, respectively. Feeding T. mercedesae with fruit fly S2 cells heterologously expressing honey bee Hymenoptaecin significantly downregulated mite Vitellogenin expression, indicating that the honey bee AMP manipulates mite reproduction upon feeding on bee. Our results provide insights into the mechanism of DWV transmission by the honey bee parasitic mite to the host, and the novel role of AMP in defending against mite infestation.

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Characterization of the Copy Number and Variants of Deformed Wing Virus (DWV) in the Pairs of Honey Bee Pupa and Infesting Varroa destructor or Tropilaelaps mercedesae

Frontiers in Microbiology ◽

10.3389/fmicb.2017.01558 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 18

Author(s):

Yunfei Wu ◽

Xiaofeng Dong ◽

Tatsuhiko Kadowaki

Keyword(s):

Honey Bee ◽

Varroa Destructor ◽

Copy Number ◽

Deformed Wing Virus ◽

Tropilaelaps Mercedesae

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Feeding by Tropilaelaps mercedesae on pre- and post-capped brood increases damage to Apis mellifera colonies

Scientific Reports ◽

10.1038/s41598-019-49662-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Patcharin Phokasem ◽

Lilia I. de Guzman ◽

Kitiphong Khongphinitbunjong ◽

Amanda M. Frake ◽

Panuwan Chantawannakul

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Brood Production ◽

Deformed Wing Virus ◽

Larval Stages ◽

Queen Cell ◽

Tropilaelaps Mercedesae ◽

Management Approaches ◽

Mite Infestations

Abstract Tropilaelaps mercedesae parasitism can cause Apis mellifera colony mortality in Asia. Here, we report for the first time that tropilaelaps mites feed on both pre- and post-capped stages of honey bees. Feeding on pre-capped brood may extend their survival outside capped brood cells, especially in areas where brood production is year-round. In this study, we examined the types of injury inflicted by tropilaelaps mites on different stages of honey bees, the survival of adult honey bees, and level of honey bee viruses in 4th instar larvae and prepupae. The injuries inflicted on different developing honey bee stages were visualised by staining with trypan blue. Among pre-capped stages, 4th instar larvae sustained the highest number of wounds (4.6 ± 0.5/larva) while 2nd-3rd larval instars had at least two wounds. Consequently, wounds were evident on uninfested capped brood (5th-6th instar larvae = 3.91 ± 0.64 wounds; prepupae = 5.25 ± 0.73 wounds). Tropilaelaps mite infestations resulted in 3.4- and 6-fold increases in the number of wounds in 5th-6th instar larvae and prepupae as compared to uninfested capped brood, respectively. When wound-inflicted prepupae metamorphosed to white-eyed pupae, all wound scars disappeared with the exuviae. This healing of wounds contributed to the reduction of the number of wounds (≤10) observed on the different pupal stages. Transmission of mite-borne virus such as Deformed Wing Virus (DWV) was also enhanced by mites feeding on early larval stages. DWV and Black Queen Cell Virus (BQCV) were detected in all 4th instar larvae and prepupae analysed. However, viral levels were more pronounced in scarred 4th instar larvae and infested prepupae. The remarkably high numbers of wounds and viral load on scarred or infested developing honey bees may have caused significant weight loss and extensive injuries observed on the abdomen, wings, legs, proboscis and antennae of adult honey bees. Together, the survival of infested honey bees was significantly compromised. This study demonstrates the ability of tropilaelaps mites to inflict profound damage on A. mellifera hosts. Effective management approaches need to be developed to mitigate tropilaelaps mite problems.

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Metagenomic Approach with the NetoVIR Enrichment Protocol Reveals Virus Diversity within Ethiopian Honey Bees (Apis mellifera simensis)

Viruses ◽

10.3390/v12111218 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1218

Author(s):

Haftom Gebremedhn ◽

Ward Deboutte ◽

Karel Schoonvaere ◽

Peter Demaeght ◽

Lina De Smet ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Sampling Site ◽

Virus Species ◽

Virus Infections ◽

Deformed Wing Virus ◽

Virus Diversity ◽

Two Samples ◽

Enrichment Protocol ◽

Metagenomic Approach

Metagenomics studies have accelerated the discovery of novel or divergent viruses of the honey bee. However, most of these studies predominantly focused on RNA viruses, and many suffer from the relatively low abundance of viral nucleic acids in the samples (i.e., compared to that of the host). Here, we explored the virome of the Ethiopian honey bee, Apis mellifera simensis, using an unbiased metagenomic approach in which the next-generation sequencing step was preceded by an enrichment protocol for viral particles. Our study revealed five well-known bee viruses and 25 atypical virus species, most of which have never been found in A. mellifera before. The viruses belong to Iflaviridae, Dicistroviridae, Secoviridae, Partitiviridae, Parvoviridae, Potyviridae, and taxonomically unclassified families. Fifteen of these atypical viruses were most likely plant-specific, and the remaining ten were presumed to be insect-specific. Apis mellifera filamentous virus (AmFV) was found in one sampling site out of 10. Two samples contained high read counts of a virus similar to Diatraea saccharales densovirus (DsDNV), which is a virus that causes high mortality in the sugarcane borer. AmFV and the DsDNV-like virus were the only DNA viruses found. Three viruses that primarily infect Drosophila spp. were also discovered: La Jolla virus (LJV), Kilifi virus (KiV), and Thika virus. Our study suggests that phoretic varroa mites are involved in the transmission of LJV and KiV and that both viruses replicate in mites and adult bees. We also found an overwhelming dominance of the deformed wing virus type B variant, which fits well with the apparently harmless infestation by Varroa destructor. It was suggested that Ethiopian bees have developed tolerance against virus infections as the result of natural selection.

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Infection of a Lepidopteran Cell Line with Deformed Wing Virus

Viruses ◽

10.3390/v12070739 ◽

2020 ◽

Vol 12 (7) ◽

pp. 739 ◽

Cited By ~ 2

Author(s):

Tal Erez ◽

Nor Chejanovsky

Keyword(s):

Cell Line ◽

Honey Bee ◽

Cell Lines ◽

Cellular Level ◽

Pcr Analysis ◽

Virus Infections ◽

Rt Pcr ◽

Deformed Wing Virus ◽

Infected Cells ◽

Bee Virus

Many attempts to develop a reliable cell cultured-based system to study honey bee virus infections have encountered substantial difficulties. We investigated the ability of a cell line from a heterologous insect to sustain infection by a honey bee virus. For this purpose, we infected the Lepidopteran hemocytic cell line (P1) with Deformed wing virus (DWV). The genomic copies of DWV increased upon infection, as monitored by quantitative RT-PCR. Moreover, a tagged-primer-based RT-PCR analysis showed the presence of DWV negative-sense RNA in the cells, indicating virus replication. However, the DWV from infected cells was mildly infectious to P1 cells. Similar results were obtained when the virus was injected into Apis mellifera pupae. Thus, though the virus yields from the infected cells appeared to be very low, we show for the first time that DWV can replicate in a heterologous cell line. Given the availability of many other insect cell lines, our study paves the way for future exploration in this direction. In the absence of adequate A. mellifera cell lines, exploring the ability of alternative cell lines to enable honey bee virus infections could provide the means to study and understand the viral infectious cycle at the cellular level and facilitate obtaining purified isolates of these viruses.

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Impact of Chronic Exposure to Sublethal Doses of Glyphosate on Honey Bee Immunity, Gut Microbiota and Infection by Pathogens

Microorganisms ◽

10.3390/microorganisms9040845 ◽

2021 ◽

Vol 9 (4) ◽

pp. 845

Author(s):

Loreley Castelli ◽

Sofía Balbuena ◽

Belén Branchiccela ◽

Pablo Zunino ◽

Joanito Liberti ◽

...

Keyword(s):

Gut Microbiota ◽

Honey Bee ◽

Chronic Exposure ◽

Pollination Services ◽

Deformed Wing Virus ◽

Immune Genes ◽

Bee Health ◽

Honey Bee Health ◽

Sublethal Doses ◽

The Impact

Glyphosate is the most used pesticide around the world. Although different studies have evidenced its negative effect on honey bees, including detrimental impacts on behavior, cognitive, sensory and developmental abilities, its use continues to grow. Recent studies have shown that it also alters the composition of the honey bee gut microbiota. In this study we explored the impact of chronic exposure to sublethal doses of glyphosate on the honey bee gut microbiota and its effects on the immune response, infection by Nosema ceranae and Deformed wing virus (DWV) and honey bee survival. Glyphosate combined with N. ceranae infection altered the structure and composition of the honey bee gut microbiota, for example by decreasing the relative abundance of the core members Snodgrassella alvi and Lactobacillus apis. Glyphosate increased the expression of some immune genes, possibly representing a physiological response to mitigate its negative effects. However, this response was not sufficient to maintain honey bee health, as glyphosate promoted the replication of DWV and decreased the expression of vitellogenin, which were accompanied by a reduced life span. Infection by N. ceranae also alters honey bee immunity although no synergistic effect with glyphosate was observed. These results corroborate previous findings suggesting deleterious effects of widespread use of glyphosate on honey bee health, and they contribute to elucidate the physiological mechanisms underlying a global decline of pollination services.

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Comparing Survival of Israeli Acute Paralysis Virus Infection among Stocks of U.S. Honey Bees

Insects ◽

10.3390/insects12010060 ◽

2021 ◽

Vol 12 (1) ◽

pp. 60

Author(s):

Shilpi Bhatia ◽

Saman S. Baral ◽

Carlos Vega Melendez ◽

Esmaeil Amiri ◽

Olav Rueppell

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Virus Infections ◽

Israeli Acute Paralysis Virus ◽

Immune Genes ◽

Starting Point ◽

Bee Health ◽

Honey Bee Health ◽

Survival Differences ◽

Paralysis Virus

Among numerous viruses that infect honey bees (Apis mellifera), Israeli acute paralysis virus (IAPV) can be linked to severe honey bee health problems. Breeding for virus resistance may improve honey bee health. To evaluate the potential for this approach, we compared the survival of IAPV infection among stocks from the U.S. We complemented the survival analysis with a survey of existing viruses in these stocks and assessing constitutive and induced expression of immune genes. Worker offspring from selected queens in a common apiary were inoculated with IAPV by topical applications after emergence to assess subsequent survival. Differences among stocks were small compared to variation within stocks, indicating the potential for improving honey bee survival of virus infections in all stocks. A positive relation between worker survival and virus load among stocks further suggested that honey bees may be able to adapt to better cope with viruses, while our molecular studies indicate that toll-6 may be related to survival differences among virus-infected worker bees. Together, these findings highlight the importance of viruses in queen breeding operations and provide a promising starting point for the quest to improve honey bee health by selectively breeding stock to be better able to survive virus infections.

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Detection of Lotmaria passim, Crithidia mellificae and Replicative Forms of Deformed Wing Virus and Kashmir Bee Virus in the Small Hive Beetle (Aethina tumida)

Pathogens ◽

10.3390/pathogens10030372 ◽

2021 ◽

Vol 10 (3) ◽

pp. 372

Author(s):

Antonio Nanetti ◽

James D. Ellis ◽

Ilaria Cardaio ◽

Giovanni Cilia

Keyword(s):

Honey Bee ◽

Aethina Tumida ◽

Small Hive Beetle ◽

Deformed Wing Virus ◽

Queen Cell ◽

Kashmir Bee Virus ◽

Acute Bee Paralysis Virus ◽

Bee Virus ◽

Paralysis Virus ◽

Lotmaria Passim

Knowledge regarding the honey bee pathogens borne by invasive bee pests remains scarce. This investigation aimed to assess the presence in Aethina tumida (small hive beetle, SHB) adults of honey bee pathogens belonging to the following groups: (i) bacteria (Paenibacillus larvae and Melissococcus plutonius), (ii) trypanosomatids (Lotmaria passim and Crithidia mellificae), and (iii) viruses (black queen cell virus, Kashmir bee virus, deformed wing virus, slow paralysis virus, sacbrood virus, Israeli acute paralysis virus, acute bee paralysis virus, chronic bee paralysis virus). Specimens were collected from free-flying colonies in Gainesville (Florida, U.S.A.) in summer 2017. The results of the molecular analysis show the presence of L. passim, C. mellificae, and replicative forms of deformed wing virus (DWV) and Kashmir bee virus (KBV). Replicative forms of KBV have not previously been reported. These results support the hypothesis of pathogen spillover between managed honey bees and the SHB, and these dynamics require further investigation.

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Deformed wing virus variant shift from 2010 to 2016 in managed and feral UK honey bee colonies

Archives of Virology ◽

10.1007/s00705-021-05162-3 ◽

2021 ◽

Author(s):

J. L. Kevill ◽

K. C. Stainton ◽

D. C. Schroeder ◽

S. J. Martin

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Small Study ◽

Deformed Wing Virus ◽

Virus Variant ◽

The Usa ◽

The Uk ◽

Bee Colonies ◽

Existing Data

AbstractDeformed wing virus (DWV) has been linked to the global decline of honey bees. DWV exists as three master variants (DWV-A, DWV-B, and DWV-C), each with differing outcomes for the honey bee host. Research in the USA showed a shift from DWV-A to DWV-B between 2010 to 2016 in honey bee colonies. Likewise, in the UK, a small study in 2007 found only DWV-A, whereas in 2016, DWV-B was the most prevalent variant. This suggests a shift from DWV-A to DWV-B might have occurred in the UK between 2007 and 2016. To investigate this further, data from samples collected in 2009/10 (n = 46) were compared to existing data from 2016 (n = 42). These samples also allowed a comparison of DWV variants between Varroa-untreated (feral) and Varroa-treated (managed) colonies. The results revealed that, in the UK, DWV-A was far more prevalent in 2009/10 (87%) than in 2016 (43%). In contrast, DWV-B was less prevalent in 2009/10 (76%) than in 2016 (93%). Regardless if colonies had been treated for Varroa (managed) or not (feral), the same trend from DWV-A to DWV-B occurred. Overall, the results reveal a decrease in DWV-A and an increase in DWV-B in UK colonies.

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