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Eugene V. Ryabov - One of the best experts on this subject based on the ideXlab platform.
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Short Communication Recombinants between Deformed wing virus and Varroa Destructor virus-1 may prevail in Varroa Destructor-infested honeybee colonies
2011Co-Authors: Jonathan D. Moore, Aleksey Jironkin, David Chandler, Nigel John Burroughs, David J.a. Evans, Eugene V. RyabovAbstract:School of Life Sciences, University of Warvick, Coventry CV4 7AL, UKWe have used high-throughput Illumina sequencing to identify novel recombinants betweenDeformed wing virus (DWV) and Varroa Destructor virus-1 (VDV-1), which accumulate to higherlevels than DWV in both honeybees and Varroa Destructor mites. The recombinants, VDV-1
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recombinants between deformed wing virus and Varroa Destructor virus 1 may prevail in Varroa Destructor infested honeybee colonies
Journal of General Virology, 2011Co-Authors: Jonathan D. Moore, Aleksey Jironkin, Nigel John Burroughs, David J.a. Evans, Dave Chandler, Eugene V. RyabovAbstract:We have used high-throughput Illumina sequencing to identify novel recombinants between Deformed wing virus (DWV) and Varroa Destructor virus-1 (VDV-1), which accumulate to higher levels than DWV in both honeybees and Varroa Destructor mites. The recombinants, VDV-1VVD and VDV-1DVD, exhibit crossovers between the 5′-UTR and the regions encoding the structural (capsid) and non-structural viral proteins. This implies that the genomes are modular and that each region may evolve independently, as demonstrated in human enteroviruses. Individual honeybee pupae were infected with a mixture of observed recombinants and DWV. A strong correlation was observed between VDV-1DVD levels in honeybee pupae and associated mites, suggesting that this recombinant, with a DWV-derived 5′-UTR and non-structural protein region flanking a VDV-1-derived capsid-encoding region, is better adapted to transmission between V. Destructor and honeybees than the parental DWV or a recombinant bearing the VDV-1-derived 5′-UTR (VDV-1VVD).
Jonathan D. Moore - One of the best experts on this subject based on the ideXlab platform.
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Short Communication Recombinants between Deformed wing virus and Varroa Destructor virus-1 may prevail in Varroa Destructor-infested honeybee colonies
2011Co-Authors: Jonathan D. Moore, Aleksey Jironkin, David Chandler, Nigel John Burroughs, David J.a. Evans, Eugene V. RyabovAbstract:School of Life Sciences, University of Warvick, Coventry CV4 7AL, UKWe have used high-throughput Illumina sequencing to identify novel recombinants betweenDeformed wing virus (DWV) and Varroa Destructor virus-1 (VDV-1), which accumulate to higherlevels than DWV in both honeybees and Varroa Destructor mites. The recombinants, VDV-1
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recombinants between deformed wing virus and Varroa Destructor virus 1 may prevail in Varroa Destructor infested honeybee colonies
Journal of General Virology, 2011Co-Authors: Jonathan D. Moore, Aleksey Jironkin, Nigel John Burroughs, David J.a. Evans, Dave Chandler, Eugene V. RyabovAbstract:We have used high-throughput Illumina sequencing to identify novel recombinants between Deformed wing virus (DWV) and Varroa Destructor virus-1 (VDV-1), which accumulate to higher levels than DWV in both honeybees and Varroa Destructor mites. The recombinants, VDV-1VVD and VDV-1DVD, exhibit crossovers between the 5′-UTR and the regions encoding the structural (capsid) and non-structural viral proteins. This implies that the genomes are modular and that each region may evolve independently, as demonstrated in human enteroviruses. Individual honeybee pupae were infected with a mixture of observed recombinants and DWV. A strong correlation was observed between VDV-1DVD levels in honeybee pupae and associated mites, suggesting that this recombinant, with a DWV-derived 5′-UTR and non-structural protein region flanking a VDV-1-derived capsid-encoding region, is better adapted to transmission between V. Destructor and honeybees than the parental DWV or a recombinant bearing the VDV-1-derived 5′-UTR (VDV-1VVD).
Giorgio Della Vedova - One of the best experts on this subject based on the ideXlab platform.
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A semiochemical from larval food influences the entrance of Varroa Destructor into brood cells
Apidologie, 2004Co-Authors: Francesco Nazzi, Norberto Milani, Giorgio Della VedovaAbstract:Chemical stimuli responsible for the biological activity of bee larval food on Varroa Destructor were studied both in the laboratory and under natural conditions. Loss of activity after neutralization and air entrainment experiments suggested that active substances were acidic and volatile. Linear, branched and aromatic carboxy-acids, as well as hydroxy-acids, were identified by GC-MS and SPME-GC-MS analysis in organic larval food extracts. The low molecular weight carboxy-acids identified were tested in a laboratory assay using a four-well arena. All the acids tested were inactive with the exception of 2- hydroxyhexanoic acid; comparison with related compounds and dose-response studies confirmed the activity of this acid at 10 and 100 ng per well showing that this is a semiochemical for the mite. One hundred nanograms of 2-hydroxyhexanoic acid applied to worker brood cells before capping increased by 36% the number of mites per cell in the treated brood compared to the control cells. 2-Hydroxyhexanoic acid / cell invasion / larval food / semiochemical / Varroa Destructor
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(Z)-8-Heptadecene reduces the reproduction of Varroa Destructor in brood cells
Apidologie, 2004Co-Authors: Norberto Milani, Giorgio Della Vedova, Francesco NazziAbstract:The alkene (Z)-8-heptadecene, a semiochemical which inhibits the reproduction of Varroa Destructor was tested in natural comb cells. One-hundred ng of (Z)-8-heptadecene applied under the capping of worker cells, sealed 0-15 h previously, caused a highly significant reduction both in the number of offspring (-12% reduction) and in the number of potentially mated daughters per female (-28% reduction) in single infested cells. No reduction was observed in multiple infested cells. A consistent, but not significant decrease was observed in cells treated at different times after capping. No decrease in mite reproduction was noted in cells treated 0-16 h before capping or 0-6 h after capping. However, infestation of cells treated before capping was reduced by 41%. In single infested cells in the control groups, the number of potentially mated daughters per female decreased from 1.5 in June to 0.78-0.94 in September. The proportion of treated cells emptied by bees was about 30% lower than that of control cells. (Z)-8-Heptadecene may play an important role in the host-parasite relationship. reproduction / Varroa Destructor / semiochemical / heptadecene
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A semiochemical from brood cells infested by Varroa Destructor triggers hygienic behaviour in Apis mellifera
Apidologie, 2004Co-Authors: Francesco Nazzi, Giorgio Della Vedova, Mauro D'agaroAbstract:Hygienic behaviour of bees towards mite infested brood is involved in the tolerance of some bee strains to Varroa Destructor. The stimuli triggering hygienic behaviour are olfactory cues emanating from cells containing infested brood but their identity is still unknown. After confirming the capacity of bees to detect and empty mite-infested cells, we studied the volatile chemicals released by artificially infested worker brood cells by means of SPME-GC-MS. The identified chemicals were then bioassayed by comparing the bees' hygienic behaviour towards treated cells into which 1 µg of each compound was injected and control cells which received the solvent alone. Z-(6)-pentadecene significantly increased the number of cells emptied by the bees. Varroa Destructor / semiochemicals / hygienic behaviour / removal / hydrocarbons
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(Z)-8-Heptadecene from infested cells reduces the reproduction of Varroa Destructor under laboratory conditions
Journal of Chemical Ecology, 2002Co-Authors: Francesco Nazzi, Norberto Milani, Giorgio Della VedovaAbstract:The parasitic mite Varroa Destructor Anderson and Trueman, the most serious threat to apiculture in many countries of the world, reproduces inside honeybee brood cells. Previous research, using artificial cells for rearing the mite on an Apis mellifera larva, indicated that semiochemicals affecting the reproduction of Varroa Destructor are released into such cells. In order to isolate these semiochemicals, infested artificial cells were extracted with hexane and the extract fractionated twice. Several unsaturated hydrocarbons were identified in the active fraction; some of them were released in higher amounts in case of infestation and were, therefore, bioassayed for their effect on the mite's reproduction. Of five alkenes tested under laboratory conditions, (Z)-8-heptadecene, caused a 30% reduction in the mean number of offspring of mites reared in cells treated with this compound.
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Decline in the proportion of mites resistant to fluvalinate in a population of Varroa Destructor not treated with pyrethroids
Apidologie, 2002Co-Authors: Norberto Milani, Giorgio Della VedovaAbstract:The reversion of resistance to pyrethroids in Varroa Destructor Anderson & Trueman was studied in Friuli (northern Italy), where resistance was detected in 1995 and pyrethroids had not been used since. Mites were sampled in seven localities each year between 1997 and 2000 and assayed in the laboratory for the resistance to fluvalinate by using paraffin coated capsules. Survival at the diagnostic concentration, expected to kill all susceptible mites (200 mg/kg), decreased in all the localities by about ten times in three years, from 19-66% to 1.3-7.8%. Thus, the disadvantage associated with the resistance to pyrethroids in V. Destructor is small, as usual when resistance is due to monooxygenases. Its impact on the selection of resistant mites during annual application of treatments is negligible; appreciable effects of reversion can be expected only over many generations of the mite. Varroa Destructor / reversion / resistance / pyrethroids
Nor Chejanovsky - One of the best experts on this subject based on the ideXlab platform.
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two novel viruses associated with the apis mellifera pathogenic mite Varroa Destructor
Scientific Reports, 2016Co-Authors: Sofia Levin, Noa Sela, Nor ChejanovskyAbstract:Varroa Destructor infestation of Apis mellifera colonies carries and/or promotes replication of honey bee viruses like the Deformed wing virus, the Varroa Destructor virus-1, the Acute bee paralysis virus, the Israeli acute bee paralysis virus and the Kashmir bee virus that have been well described and characterized; but viruses exclusively associated with Varroa were not found. To look for viruses that may associate with- or infect V. Destructor we performed deep sequencing (RNA-seq) of RNA extracted from honey bees and mites in Varroa-infested untreated colonies. Comparative bioinformatic analysis of the two separate contig-assemblies generated from the sequences’ reads annotated using Blastx enabled identification of new viruses unique to Varroa and absent in A. mellifera: an Iflavirus and a virus with homology to Ixodes scapularis associated virus 2, that we named Varroa Destructor virus 2 (VDV-2) and 3(VDV-3), respectively. We validated these findings sequencing the mite- and honey bee-viromes and in separate mites and honey bees randomly sampled. The complete genomes of VDV-2 and VDV-3 bear 9576 nucleotides and 4202 nucleotides, respectively. Phylogenetic analysis of VDV-3 suggests that it belongs to a new group of viruses. Our results open venues for investigating the pathogenicity of these V. Destructor viruses.
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Varroa Destructor research avenues towards sustainable control
Journal of Apicultural Research, 2012Co-Authors: Vincent Dietemann, Nor Chejanovsky, Benjamin Dainat, Jochen Pflugfelder, Denis L Anderson, Jeandaniel Charriere, Joachim R De Miranda, Keith S Delaplane, Franzxaver Dillier, Stefan FuchAbstract:SummaryPollination by honey bees plays a key role in the functioning of ecosystems and optimisation of agricultural yields. Severe honey bee colony losses worldwide have raised concerns about the sustainability of these pollination services. In many cases, bee mortality appears to be the product of many interacting factors, but there is a growing consensus that the ectoparasitic mite Varroa Destructor plays the role of the major predisposing liability. We argue that the fight against this mite should be a priority for future honey bee health research. We highlight the lack of efficient control methods currently available against the parasite and discuss the need for new approaches. Gaps in our knowledge of the biology and epidemiology of the mite are identified and a research road map towards sustainable control is drawn. Innovative and challenging approaches are suggested in order to stimulate research efforts and ensure that honey bees will be able to sustainably fulfil their role in the ecosystem.
Francesco Nazzi - One of the best experts on this subject based on the ideXlab platform.
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A semiochemical from larval food influences the entrance of Varroa Destructor into brood cells
Apidologie, 2004Co-Authors: Francesco Nazzi, Norberto Milani, Giorgio Della VedovaAbstract:Chemical stimuli responsible for the biological activity of bee larval food on Varroa Destructor were studied both in the laboratory and under natural conditions. Loss of activity after neutralization and air entrainment experiments suggested that active substances were acidic and volatile. Linear, branched and aromatic carboxy-acids, as well as hydroxy-acids, were identified by GC-MS and SPME-GC-MS analysis in organic larval food extracts. The low molecular weight carboxy-acids identified were tested in a laboratory assay using a four-well arena. All the acids tested were inactive with the exception of 2- hydroxyhexanoic acid; comparison with related compounds and dose-response studies confirmed the activity of this acid at 10 and 100 ng per well showing that this is a semiochemical for the mite. One hundred nanograms of 2-hydroxyhexanoic acid applied to worker brood cells before capping increased by 36% the number of mites per cell in the treated brood compared to the control cells. 2-Hydroxyhexanoic acid / cell invasion / larval food / semiochemical / Varroa Destructor
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(Z)-8-Heptadecene reduces the reproduction of Varroa Destructor in brood cells
Apidologie, 2004Co-Authors: Norberto Milani, Giorgio Della Vedova, Francesco NazziAbstract:The alkene (Z)-8-heptadecene, a semiochemical which inhibits the reproduction of Varroa Destructor was tested in natural comb cells. One-hundred ng of (Z)-8-heptadecene applied under the capping of worker cells, sealed 0-15 h previously, caused a highly significant reduction both in the number of offspring (-12% reduction) and in the number of potentially mated daughters per female (-28% reduction) in single infested cells. No reduction was observed in multiple infested cells. A consistent, but not significant decrease was observed in cells treated at different times after capping. No decrease in mite reproduction was noted in cells treated 0-16 h before capping or 0-6 h after capping. However, infestation of cells treated before capping was reduced by 41%. In single infested cells in the control groups, the number of potentially mated daughters per female decreased from 1.5 in June to 0.78-0.94 in September. The proportion of treated cells emptied by bees was about 30% lower than that of control cells. (Z)-8-Heptadecene may play an important role in the host-parasite relationship. reproduction / Varroa Destructor / semiochemical / heptadecene
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A semiochemical from brood cells infested by Varroa Destructor triggers hygienic behaviour in Apis mellifera
Apidologie, 2004Co-Authors: Francesco Nazzi, Giorgio Della Vedova, Mauro D'agaroAbstract:Hygienic behaviour of bees towards mite infested brood is involved in the tolerance of some bee strains to Varroa Destructor. The stimuli triggering hygienic behaviour are olfactory cues emanating from cells containing infested brood but their identity is still unknown. After confirming the capacity of bees to detect and empty mite-infested cells, we studied the volatile chemicals released by artificially infested worker brood cells by means of SPME-GC-MS. The identified chemicals were then bioassayed by comparing the bees' hygienic behaviour towards treated cells into which 1 µg of each compound was injected and control cells which received the solvent alone. Z-(6)-pentadecene significantly increased the number of cells emptied by the bees. Varroa Destructor / semiochemicals / hygienic behaviour / removal / hydrocarbons
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(Z)-8-Heptadecene from infested cells reduces the reproduction of Varroa Destructor under laboratory conditions
Journal of Chemical Ecology, 2002Co-Authors: Francesco Nazzi, Norberto Milani, Giorgio Della VedovaAbstract:The parasitic mite Varroa Destructor Anderson and Trueman, the most serious threat to apiculture in many countries of the world, reproduces inside honeybee brood cells. Previous research, using artificial cells for rearing the mite on an Apis mellifera larva, indicated that semiochemicals affecting the reproduction of Varroa Destructor are released into such cells. In order to isolate these semiochemicals, infested artificial cells were extracted with hexane and the extract fractionated twice. Several unsaturated hydrocarbons were identified in the active fraction; some of them were released in higher amounts in case of infestation and were, therefore, bioassayed for their effect on the mite's reproduction. Of five alkenes tested under laboratory conditions, (Z)-8-heptadecene, caused a 30% reduction in the mean number of offspring of mites reared in cells treated with this compound.
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Semiochemicals from larval food affect the locomotory behaviour of Varroa Destructor
Apidologie, 2001Co-Authors: Francesco Nazzi, Giorgio Della Vedova, Norberto Milani, Matteo NimisAbstract:The stimuli inducing cell invasion by Varroa Destructorwere studied using a bioassay in which a mite was observed in a glass arena with four wells, each containing a live bee larva, treated or not with the stimulus to be tested. Larval food collected from drone cells before capping elicited a strong response from V. Destructor. Both ether and acetone extracts of larval food induced the same response as larval food itself suggesting the existence of semiochemicals attracting or arresting the mite. Varroa Destructor / semiochemicals / larval food / brood cell invasion
