scholarly journals Adapted tolerance to virus infections in four geographically distinct Varroa destructor-resistant honeybee populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Locke ◽  
Srinivas Thaduri ◽  
Jörg G. Stephan ◽  
Matthew Low ◽  
Tjeerd Blacquière ◽  
...  

AbstractThe ectoparasitic mite, Varroa destructor, is unarguably the leading cause of honeybee (Apis mellifera) mortality worldwide through its role as a vector for lethal viruses, in particular, strains of the Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV) complexes. Several honeybee populations across Europe have well-documented adaptations of mite-resistant traits but little is known about host adaptations towards the virus infections vectored by the mite. The aim of this study was to assess and compare the possible contribution of adapted virus tolerance and/or resistance to the enhanced survival of four well-documented mite-resistant honeybee populations from Norway, Sweden, The Netherlands and France, in relation to unselected mite-susceptible honeybees. Caged adult bees and laboratory reared larvae, from colonies of these four populations, were inoculated with DWV and ABPV in a series of feeding infection experiments, while control groups received virus-free food. Virus infections were monitored using RT-qPCR assays in individuals sampled over a time course. In both adults and larvae the DWV and ABPV infection dynamics were nearly identical in all groups, but all mite-resistant honeybee populations had significantly higher survival rates compared to the mite-susceptible honeybees. These results suggest that adapted virus tolerance is an important component of survival mechanisms.

2011 ◽  
Vol 78 (1) ◽  
pp. 227-235 ◽  
Author(s):  
Barbara Locke ◽  
Eva Forsgren ◽  
Ingemar Fries ◽  
Joachim R. de Miranda

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.


2004 ◽  
Vol 70 (12) ◽  
pp. 7185-7191 ◽  
Author(s):  
Diana Tentcheva ◽  
Laurent Gauthier ◽  
Nathalie Zappulla ◽  
Benjamin Dainat ◽  
François Cousserans ◽  
...  

ABSTRACT A survey of six bee viruses on a large geographic scale was undertaken by using seemingly healthy bee colonies and the PCR technique. Samples of adult bees and pupae were collected from 36 apiaries in the spring, summer, and autumn during 2002. Varroa destructor samples were collected at the end of summer following acaricide treatment. In adult bees, during the year deformed wing virus (DWV) was found at least once in 97% of the apiaries, sacbrood virus (SBV) was found in 86% of the apiaries, chronic bee paralysis virus (CBPV) was found in 28% of the apiaries, acute bee paralysis virus (ABPV) was found in 58% of the apiaries, black queen cell virus (BQCV) was found in 86% of the apiaries, and Kashmir bee virus (KBV) was found in 17% of the apiaries. For pupae, the following frequencies were obtained: DWV, 94% of the apiaries; SBV, 80% of the apiaries; CBPV, none of the apiaries; ABPV, 23% of the apiaries; BQCV, 23% of the apiaries; and KBV, 6% of the apiaries. In Varroa samples, the following four viruses were identified: DWV (100% of the apiaries), SBV (45% of the apiaries), ABPV (36% of the apiaries), and KBV (5% of the apiaries). The latter findings support the putative role of mites in transmitting these viruses. Taken together, these data indicate that bee virus infections occur persistently in bee populations despite the lack of clinical signs, suggesting that colony disease outbreaks might result from environmental factors that lead to activation of viral replication in bees.


2011 ◽  
Vol 78 (4) ◽  
pp. 981-987 ◽  
Author(s):  
Benjamin Dainat ◽  
Jay D. Evans ◽  
Yan Ping Chen ◽  
Laurent Gauthier ◽  
Peter Neumann

ABSTRACTElevated winter losses of managed honeybee colonies are a major concern, but the underlying mechanisms remain controversial. Among the suspects are the parasitic miteVarroa destructor, the microsporidianNosema ceranae, and associated viruses. Here we hypothesize that pathogens reduce the life expectancy of winter bees, thereby constituting a proximate mechanism for colony losses. A monitoring of colonies was performed over 6 months in Switzerland from summer 2007 to winter 2007/2008. Individual dead workers were collected daily and quantitatively analyzed for deformed wing virus (DWV), acute bee paralysis virus (ABPV),N. ceranae, and expression levels of thevitellogeningene as a biomarker for honeybee longevity. Workers from colonies that failed to survive winter had a reduced life span beginning in late fall, were more likely to be infected with DWV, and had higher DWV loads. Colony levels of infection with the parasitic miteVarroa destructorand individual infections with DWV were also associated with reduced honeybee life expectancy. In sharp contrast, the level ofN. ceranaeinfection was not correlated with longevity. In addition,vitellogeningene expression was significantly positively correlated with ABPV andN. ceranaeloads. The findings strongly suggest thatV. destructorand DWV (but neitherN. ceranaenor ABPV) reduce the life span of winter bees, thereby constituting a parsimonious possible mechanism for honeybee colony losses.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 372
Author(s):  
Antonio Nanetti ◽  
James D. Ellis ◽  
Ilaria Cardaio ◽  
Giovanni Cilia

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.


2005 ◽  
Vol 86 (12) ◽  
pp. 3419-3424 ◽  
Author(s):  
Constanze Yue ◽  
Elke Genersch

Deformed wing virus (DWV) is a honeybee viral pathogen either persisting as an inapparent infection or resulting in wing deformity. The occurrence of deformity is associated with the transmission of DWV through Varroa destructor during pupal stages. Such infections with DWV add to the pathology of V. destructor and play a major role in colony collapse in the course of varroosis. Using a recently developed RT-PCR protocol for the detection of DWV, individual bees and mites originating from hives differing in Varroa infestation levels and the occurrence of crippled bees were analysed. It was found that 100 % of both crippled and asymptomatic bees were positive for DWV. However, a significant difference in the spatial distribution of DWV between asymptomatic and crippled bees could be demonstrated: when analysing head, thorax and abdomen of crippled bees, all body parts were always strongly positive for viral sequences. In contrast, for asymptomatic bees viral sequences could be detected in RNA extracted from the thorax and/or abdomen but never in RNA extracted from the head. DWV replication was demonstrated in almost all DWV-positive body parts of infected bees. Analysing individual mites for the presence of DWV revealed that the percentage of DWV-positive mites differed between mite populations. In addition, it was demonstrated that DWV was able to replicate in some but not all mites. Interestingly, virus replication in mites was correlated with wing deformity. DWV was also detected in the larval food, implicating that in addition to transmission by V. destructor DWV is also transmitted by feeding.


2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Giuseppina Tantillo ◽  
Marilisa Bottaro ◽  
Angela Di Pinto ◽  
Vito Martella ◽  
Pietro Di Pinto ◽  
...  

The health and vigour of honeybee colonies are threatened by numerous parasites (such as <em>Varroa destructor</em> and <em>Nosema</em> spp.) and pathogens, including viruses, bacteria, protozoa. Among honeybee pathogens, viruses are one of the major threats to the health and wellbeing of honeybees and cause serious concern for researchers and beekeepers. To tone down the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally benign disease control strategies. Here we summarize recent progress in the understanding of the morphology, genome organization, transmission, epidemiology and pathogenesis of eight honeybee viruses: Deformed wing virus (DWV) and Kakugo virus (KV); Sacbrood virus (SBV); Black Queen cell virus (BQCV); Acute bee paralysis virus (ABPV); Kashmir bee virus (KBV); Israeli Acute Paralysis Virus (IAPV); Chronic bee paralysis virus (CBPV). The review has been designed to provide researchers in the field with updated information about honeybee viruses and to serve as a starting point for future research.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Desiderato Annoscia ◽  
Gennaro Di Prisco ◽  
Andrea Becchimanzi ◽  
Emilio Caprio ◽  
Davide Frizzera ◽  
...  

AbstractThe neonicotinoid Clothianidin has a negative impact on NF-κB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees.


Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 133 ◽  
Author(s):  
Magen E. Francis ◽  
Mara McNeil ◽  
Nicholas J. Dawe ◽  
Mary K. Foley ◽  
Morgan L. King ◽  
...  

Influenza virus imprinting is now understood to significantly influence the immune responses and clinical outcome of influenza virus infections that occur later in life. Due to the yearly cycling of influenza viruses, humans are imprinted with the circulating virus of their birth year and subsequently build a complex influenza virus immune history. Despite this knowledge, little is known about how the imprinting strain influences vaccine responses. To investigate the immune responses of the imprinted host to split-virion vaccination, we imprinted ferrets with a sublethal dose of the historical seasonal H1N1 strain A/USSR/90/1977. After a +60-day recovery period to build immune memory, ferrets were immunized and then challenged on Day 123. Antibody specificity and recall were investigated throughout the time course. At challenge, the imprinted vaccinated ferrets did not experience significant disease, while naïve-vaccinated ferrets had significant weight loss. Haemagglutination inhibition assays showed that imprinted ferrets had a more robust antibody response post vaccination and increased virus neutralization activity. Imprinted-vaccinated animals had increased virus-specific IgG antibodies compared to the other experimental groups, suggesting B-cell maturity and plasticity at vaccination. These results should be considered when designing the next generation of influenza vaccines.


2014 ◽  
Vol 64 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Predrag Simeunović ◽  
Jevrosima Stevanović ◽  
Dejan Vidanović ◽  
Jakov Nišavić ◽  
Dejan Radović ◽  
...  

Abstract In this study 55 honey bee colonies from different Serbian regions were monitored for the presence of Deformed Wing Virus (DWV) and Acute Bee Paralysis Virus (ABPV) using TaqMan-based real-time RT-PCR assay. The results revealed the presence of DWV in each sampling location, and ABPV in 10 out of 11 apiaries. High frequency of DWV (76.4%) and ABPV (61.8%) positive samples in asymptomatic colonies can be the consequence of inefficient and postponed Varroa treatment concerning the role of this mite in the transmission and activation of honey bee viruses. The real-time RTPCR technique described in this paper is proved to be the most reliable method for this kind of investigation.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Morgan A Roth ◽  
James M Wilson ◽  
Keith R Tignor ◽  
Aaron D Gross

Abstract Varroa mite (Varroa destructor Anderson and Trueman) infestation of European honey bee (Apis mellifera L.) colonies has been a growing cause of international concern among beekeepers throughout the last 50 yr. Varroa destructor spread from the Asian honey bee (Apis cerana Fabricius [Hymenoptera: Apidae]) to A. mellifera populations in Europe in the 1970s, and subsequently traveled to the Americas. In addition to causing damage through feeding upon lipids of larval and adult bees, V. destructor also facilitates the spread of several viruses, with deformed wing virus being most prevalent. Several sampling methods have been developed for estimating infestation levels of A. mellifera colonies, and acaricide treatments have been implemented. However, overuse of synthetic acaricides in the past has led to widespread acaricide resistant V. destructor populations. The application of Integrated Pest Management (IPM) techniques is a more recent development in V. destructor control and is suggested to be more effective than only using pesticides, thereby posing fewer threats to A. mellifera colonies. When using IPM methods, informed management decisions are made based upon sampling, and cultural and mechanical controls are implemented prior to use of acaricide treatments. If acaricides are deemed necessary, they are rotated based on their mode of action, thus avoiding V. destructor resistance development.


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