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New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera

Varroa destructor Anderson and Trueman, is an ectoparasitic mite of honey bees, Apis mellifera L., that has been considered a major cause of colony losses. Synthetic miticides have been developed and registered to manage this ectoparasite, however, resistance to registered pyrethroid and organophosp...

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Autores principales: Bahreini, Rassol, Nasr, Medhat, Docherty, Cassandra, Feindel, David, Muirhead, Samantha, de Herdt, Olivia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075223/
https://www.ncbi.nlm.nih.gov/pubmed/33901245
http://dx.doi.org/10.1371/journal.pone.0250594
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author Bahreini, Rassol
Nasr, Medhat
Docherty, Cassandra
Feindel, David
Muirhead, Samantha
de Herdt, Olivia
author_facet Bahreini, Rassol
Nasr, Medhat
Docherty, Cassandra
Feindel, David
Muirhead, Samantha
de Herdt, Olivia
author_sort Bahreini, Rassol
collection PubMed
description Varroa destructor Anderson and Trueman, is an ectoparasitic mite of honey bees, Apis mellifera L., that has been considered a major cause of colony losses. Synthetic miticides have been developed and registered to manage this ectoparasite, however, resistance to registered pyrethroid and organophosphate Varroacides have already been reported in Canada. To test toxicity of miticides, current contact-based bioassay methods are designed to evaluate mites and bees separately, however, these methods are unlikely to give an accurate depiction of how miticides interact at the colony level. Therefore, the objective of this study was to develop a bioassay cage for testing the toxicity of miticides on honey bees and Varroa mites simultaneously using amitraz as a reference chemical. A 800 mL polypropylene plastic cage holding 100–150 bees was designed and officially named “Apiarium”. A comparison of the effects of three subsequent dilutions of amitraz was conducted on: Varroa mites placed in glass vials, honey bees in glass Mason jars, and Varroa-infested bees in Apiariums. Our results indicated cumulative Varroa mortality was dose-dependent in the Apiarium after 4 h and 24 h assessments. Apiarium and glass vial treatments at 24 h also had high mite mortality and a positive polynomial regression between Varroa mortality and amitraz dose rates. Moreover, chemical application in the Apiarium was less toxic for bees compared to the Mason jar method. Considering these results, the Apiarium bioassay provides a simple, cheap and reliable method for simultaneous chemical screening on V. destructor and A. mellifera. Furthermore, as mites and bees are tested together, the Apiarium simulates a colony-like environment that provides a necessary bridge between laboratory bioassay testing and full field experimentation. The versatility of the Apiarium allows researchers to test a multitude of different honey bee bioassay experiments including miticide screening, delivery methods for chemical products, or development of new mite resistance-testing methodology.
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spelling pubmed-80752232021-05-05 New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera Bahreini, Rassol Nasr, Medhat Docherty, Cassandra Feindel, David Muirhead, Samantha de Herdt, Olivia PLoS One Research Article Varroa destructor Anderson and Trueman, is an ectoparasitic mite of honey bees, Apis mellifera L., that has been considered a major cause of colony losses. Synthetic miticides have been developed and registered to manage this ectoparasite, however, resistance to registered pyrethroid and organophosphate Varroacides have already been reported in Canada. To test toxicity of miticides, current contact-based bioassay methods are designed to evaluate mites and bees separately, however, these methods are unlikely to give an accurate depiction of how miticides interact at the colony level. Therefore, the objective of this study was to develop a bioassay cage for testing the toxicity of miticides on honey bees and Varroa mites simultaneously using amitraz as a reference chemical. A 800 mL polypropylene plastic cage holding 100–150 bees was designed and officially named “Apiarium”. A comparison of the effects of three subsequent dilutions of amitraz was conducted on: Varroa mites placed in glass vials, honey bees in glass Mason jars, and Varroa-infested bees in Apiariums. Our results indicated cumulative Varroa mortality was dose-dependent in the Apiarium after 4 h and 24 h assessments. Apiarium and glass vial treatments at 24 h also had high mite mortality and a positive polynomial regression between Varroa mortality and amitraz dose rates. Moreover, chemical application in the Apiarium was less toxic for bees compared to the Mason jar method. Considering these results, the Apiarium bioassay provides a simple, cheap and reliable method for simultaneous chemical screening on V. destructor and A. mellifera. Furthermore, as mites and bees are tested together, the Apiarium simulates a colony-like environment that provides a necessary bridge between laboratory bioassay testing and full field experimentation. The versatility of the Apiarium allows researchers to test a multitude of different honey bee bioassay experiments including miticide screening, delivery methods for chemical products, or development of new mite resistance-testing methodology. Public Library of Science 2021-04-26 /pmc/articles/PMC8075223/ /pubmed/33901245 http://dx.doi.org/10.1371/journal.pone.0250594 Text en © 2021 Bahreini et al https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Bahreini, Rassol
Nasr, Medhat
Docherty, Cassandra
Feindel, David
Muirhead, Samantha
de Herdt, Olivia
New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title_full New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title_fullStr New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title_full_unstemmed New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title_short New bioassay cage methodology for in vitro studies on Varroa destructor and Apis mellifera
title_sort new bioassay cage methodology for in vitro studies on varroa destructor and apis mellifera
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075223/
https://www.ncbi.nlm.nih.gov/pubmed/33901245
http://dx.doi.org/10.1371/journal.pone.0250594
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