scholarly journals Resistance to amitraz in the parasitic honey bee mite Varroa destructor is associated with mutations in the β-adrenergic-like octopamine receptor

2021 ◽  
Author(s):  
Carmen Sara Hernández-Rodríguez ◽  
Sara Moreno-Martí ◽  
Gabrielle Almecija ◽  
Krisztina Christmon ◽  
Josephine D. Johnson ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Colony Losses ◽  
High Loss ◽  
Diagnostic Assays ◽  
Treatment Regimens ◽  
Taqman Technology ◽  
Evolution Of Resistance ◽  
Octopamine Receptor ◽  
High Loss Rate

AbstractVarroa destructor is considered a major reason for high loss rate of Western honey bee (Apis mellifera) colonies. To prevent colony losses caused by V. destructor, it is necessary to actively manage the mite population. Beekeepers, particularly commercial beekeepers, have few alternative treatments other than synthetic acaricides to control the parasite, resulting in intensive treatment regimens that led to the evolution of resistance in mite populations. To investigate the mechanism of the resistance to amitraz detected in V. destructor mites from French and U.S. apiaries, we identified and characterized octopamine and tyramine receptors (the known targets of amitraz) in this species. The comparison of sequences obtained from mites collected from different apiaries with different treatment regimens, showed that the amino acid substitutions N87S or Y215H in the OctβR were associated with treatment failures reported in French or U.S. apiaries, respectively. Based on our findings, we have developed and tested two high throughput diagnostic assays based on TaqMan technology able to accurately detect mites carrying the mutations in this receptor. This valuable information may be of help for beekeepers when selecting the most suitable acaricide to manage V. destructor.

scholarly journals Resistance to amitraz in the parasitic honey bee mite Varroa destructor is associated with mutations in the β-adrenergic-like octopamine receptor

2021 ◽  
Author(s):  
Carmen Sara Hernández-Rodríguez ◽  
Sara Moreno-Martí ◽  
Gabrielle Almecija ◽  
Krisztina Christmon ◽  
Josephine D. Johnson ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Loss Rate ◽  
Colony Losses ◽  
High Loss ◽  
Diagnostic Assays ◽  
Treatment Regimens ◽  
Evolution Of Resistance ◽  
Octopamine Receptor ◽  
High Loss Rate

Varroa destructor is considered a major reason for high loss rate of Western honey bee (Apis mellifera) colonies. To prevent colony losses caused by V. destructor it is necessary to actively manage the mite population. Beekeepers, particularly commercial beekeepers, have few alternative treatments other than synthetic acaricides to control the parasite, resulting in intensive treatment regimens that led to the evolution of resistance in mite populations. To investigate the mechanism of the resistance to amitraz detected in V. destructor mites from French and U.S. apiaries, we identified and characterized octopamine and tyramine receptors (the known targets of amitraz) in this species. The comparison of sequences obtained from mites collected from different apiaries with different treatment regimens, showed that the amino acid substitutions N87S or Y215H in the OctβR were associated with treatment failures reported in French or U.S. apiaries, respectively. Based on our findings, we have developed and tested two high throughput diagnostic assays based on TaqMan® able to accurately detect mites carrying the mutations in this receptor. This valuable information may be of help for beekeepers when selecting the most suitable acaricide to manage V. destructor.

scholarly journals Advances and perspectives in selecting resistance traits against the parasitic mite Varroa destructor in honey bees

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Matthieu Guichard ◽  
Vincent Dietemann ◽  
Markus Neuditschko ◽  
Benjamin Dainat
Keyword(s):  
Honey Bee ◽  
Environmental Effects ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Selection Strategy ◽  
Pollination Services ◽  
Colony Losses ◽  
New Host ◽  
Parasitic Mite ◽  
Resistance Traits

Abstract Background In spite of the implementation of control strategies in honey bee (Apis mellifera) keeping, the invasive parasitic mite Varroa destructor remains one of the main causes of colony losses in numerous countries. Therefore, this parasite represents a serious threat to beekeeping and agro-ecosystems that benefit from the pollination services provided by honey bees. To maintain their stocks, beekeepers have to treat their colonies with acaricides every year. Selecting lineages that are resistant to infestations is deemed to be a more sustainable approach. Review Over the last three decades, numerous selection programs have been initiated to improve the host–parasite relationship and to support honey bee survival in the presence of the parasite without the need for acaricide treatments. Although resistance traits have been included in the selection strategy of honey bees, it has not been possible to globally solve the V. destructor problem. In this study, we review the literature on the reasons that have potentially limited the success of such selection programs. We compile the available information to assess the relevance of selected traits and the potential environmental effects that distort trait expression and colony survival. Limitations to the implementation of these traits in the field are also discussed. Conclusions Improving our knowledge of the mechanisms underlying resistance to V. destructor to increase trait relevance, optimizing selection programs to reduce environmental effects, and communicating selection outcomes are all crucial to efforts aiming at establishing a balanced relationship between the invasive parasite and its new host.

scholarly journals Reduced Postcapping Period in Honey Bees Surviving Varroa destructor by Means of Natural Selection

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 149 ◽  
Author(s):  
Melissa Oddie ◽  
Bjørn Dahle ◽  
Peter Neumann
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Common Garden ◽  
Colony Losses ◽  
Susceptible Population ◽  
Key Factor ◽  
Worker Brood ◽  
Colony Survival

The ectoparasitic mite Varroa destructor is a key factor for colony losses in European honey bee subspecies (Apis mellifera), but it is also known that some host populations have adapted to the mite by means of natural selection. The role of a shorter host brood postcapping period in reducing mite reproductive success has been investigated in other surviving subspecies, however its role in the adaptation of European honey bee populations has not been addressed. Here, we use a common garden approach to compare the length of the worker brood postcapping period in a Norwegian surviving honey bee population with the postcapping period of a local susceptible population. The data show a significantly shorter postcapping period in the surviving population for ~10% of the brood. Since even small differences in postcapping period can significantly reduce mite reproductive success, this mechanism may well contribute to natural colony survival. It appears most likely that several mechanisms acting together produce the full mite-surviving colony phenotype.

scholarly journals Accelerated Varroa destructor population growth in honey bee (Apis mellifera) colonies is associated with visitation from non-natal bees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kelly Kulhanek ◽  
Andrew Garavito ◽  
Dennis vanEngelsdorp
Keyword(s):  
Population Growth ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Management Implications ◽  
Treatment Regimens ◽  
Bee Colony ◽  
The Us ◽  
Return Home ◽  
Honey Bee Colony ◽  
Host Parasite

AbstractA leading cause of managed honey bee colony mortality in the US, Varroa destructor populations typically exceed damaging levels in the fall. One explanation for rapid population increases is migration of mite carrying bees between colonies. Here, the degree to which bees from high and low mite donor colonies move between apiaries, and the effect visitation has on Varroa populations was monitored. More bees from low mite colonies (n = 37) were detected in receiver apiaries than bees from high mite colonies (n = 10, p < 0.001). Receiver colony Varroa population growth was associated with visitation by non-natal bees (p = 0.03), but not high mite bees alone (p = 0.19). Finally, colonies lacking robbing screens experienced faster Varroa population growth than screened neighbors (p = 0.01). Results indicate visiting non-natal bees may vector mites to receiver colonies. These results do not support the current two leading theories regarding mite immigration – the “mite bomb” theory (bees from high mite colonies emigrating to collapsing colonies), or the “robbing” theory (natal robbing bees return home with mites from collapsing colonies). Potential host-parasite effects to bee behavior, as well as important management implications both for Varroa treatment regimens and breeding Varroa resistant bees are discussed.

scholarly journals Large-scale monitoring of resistance to coumaphos, amitraz and pyrethroids in Varroa destructor

2020 ◽  
Author(s):  
Carmen Sara Hernández-Rodríguez ◽  
Óscar Marín ◽  
Fernando Calatayud ◽  
María José Mahiques ◽  
Ana Mompó ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Significant Variation ◽  
Large Scale ◽  
The Other ◽  
List Type ◽  
The World ◽  
Evolution Of Resistance ◽  
Bee Colonies

ABSTRACTVarroa destructor is an ectoparasitic mite causing devastating damages to honey bee colonies around the world. Its impact is considered a major factor contributing to the significant seasonal losses of colonies recorded every year. Beekeepers are usually relying on a reduced set of acaricides to manage the parasite, usually the pyrethroids tau-fluvalinate or flumethrin, the organophosphate coumaphos and the formamidine amitraz. However, the evolution of resistance in the populations is leading to an unsustainable scenario with almost no alternatives to reach an adequate control of the mite.Here we present the results from the first, large-scale and extensive monitoring of the susceptibility to acaricides in the Comunitat Valenciana, one of the most prominent apicultural regions in Spain. Our ultimate goal was to provide beekeepers with timely information to help them decide what would be the best alternative for a long-term control of the mites in their apiaries. Our data show that there is a significant variation in the expected efficacy of coumaphos and pyrethroids across the region, indicating the presence of a different ratio of resistant individuals to these acaricides in each population. On the other hand, the expected efficacy of amitraz was more consistent, although slightly below the expected efficacy according to the label.HIGHLIGHTSVarroa destructor is causing severe damages to honey bee colonies worldwide.There are very few acaricides available to manage the parasite.The evolution of resistance is limiting our capacity to control the mite.We estimated the expected efficacy of the main acaricides in many Spanish apiaries.The information was shared with beekeepers for them to decide the best treatment to control the mite.

scholarly journals Raised seasonal temperatures reinforce autumn Varroa destructor infestation in honey bee colonies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Szymon Smoliński ◽  
Aleksandra Langowska ◽  
Adam Glazaczow
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Extended Period ◽  
Effect Of Temperature ◽  
Time Lags ◽  
Climatic Effects ◽  
Colony Losses ◽  
Phenological Changes ◽  
Bee Colonies ◽  
Bee Abundance

AbstractVarroa destructor is the main pest of the honey bee Apis mellifera, causing colony losses. We investigated the effect of temperature on the autumn abundance of V. destructor in bee colonies over 1991–2020 in Central Europe. We tested the hypothesis that temperature can affect autumn mite populations with different time-lags modulating the bee abundance and brood availability. We showed that raised spring (March–May) and autumn (October) temperatures reinforce autumn V. destructor infestation in the bee colonies. The critical temperature signals embrace periods of bee activity, i.e., just after the first cleansing flights and just before the last observed bee flights, but no direct effects of phenological changes on V. destructor abundance were found. These effects were potentially associated with increased bee reproduction in the specific periods of the year and not with the extended period of activity or accelerated spring onset. We found significant effects of autumn bee abundance, autumn capped brood abundance, and the number of colonies merged on autumn mite infestation. We also observed differences in V. destructor abundance between bees derived from different subspecies. We indicated that climatic effects, through influence on the bee abundance and brood availability, are one of the main drivers regulating V. destructor abundance.

scholarly journals Evaluating toxicity of Varroa mite (Varroa destructor)-active dsRNA to monarch butterfly (Danaus plexippus) larvae

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251884
Author(s):  
Niranjana Krishnan ◽  
Maura J. Hall ◽  
Richard L. Hellmich ◽  
Joel R. Coats ◽  
Steven P. Bradbury
Keyword(s):  
Honey Bee ◽  
Base Pair ◽  
Varroa Destructor ◽  
Sublethal Effects ◽  
Larval Mortality ◽  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Varroa Mite ◽  
Colony Losses ◽  
Varroa Mites

Varroa mites (Varroa destructor) are parasitic mites that, combined with other factors, are contributing to high levels of honey bee (Apis mellifera) colony losses. A Varroa-active dsRNA was recently developed to control Varroa mites within honey bee brood cells. This dsRNA has 372 base pairs that are homologous to a sequence region within the Varroa mite calmodulin gene (cam). The Varroa-active dsRNA also shares a 21-base pair match with monarch butterfly (Danaus plexippus) calmodulin mRNA, raising the possibility of non-target effects if there is environmental exposure. We chronically exposed the entire monarch larval stage to common (Asclepias syriaca) and tropical (Asclepias curassavica) milkweed leaves treated with concentrations of Varroa-active dsRNA that are one- and ten-fold higher than those used to treat honey bee hives. This corresponded to concentrations of 0.025–0.041 and 0.211–0.282 mg/g leaf, respectively. Potassium arsenate and a previously designed monarch-active dsRNA with a 100% base pair match to the monarch v-ATPase A mRNA (leaf concentration was 0.020–0.034 mg/g) were used as positive controls. The Varroa mite and monarch-active dsRNA’s did not cause significant differences in larval mortality, larval or pupal development, pupal weights, or adult eclosion rates when compared to negative controls. Irrespective of control or dsRNA treatment, larvae that consumed approximately 7500 to 10,500-mg milkweed leaf within 10 to 12 days had the highest pupal weights. The lack of mortality and sublethal effects following dietary exposure to dsRNA with 21-base pair and 100% base pair match to mRNAs that correspond to regulatory genes suggest monarch mRNA may be refractory to silencing by dsRNA or monarch dsRNase may degrade dsRNA to a concentration that is insufficient to silence mRNA signaling.

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